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Sayed M, Qi K, Wu X, Zhang L, García H, Yu J. Cu-based S-scheme photocatalysts. Chem Soc Rev 2025; 54:4874-4921. [PMID: 40171772 DOI: 10.1039/d4cs01091d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2025]
Abstract
S-scheme heterojunctions have become a hot topic in photocatalysis. Copper (Cu) compounds are a versatile family of photocatalytic materials, including oxides (CuO, Cu2O), binary oxides (CuBi2O4, CuFe2O4), sulfides (CuxS, (1 ≤ x ≤ 2)), selenides (CuSe), phosphides (Cu3P), metal organic frameworks (MOFs), etc. These materials are characterized by narrow bandgaps, large absorption coefficients, and suitable band positions. To further increase the efficiency of photoinduced charge separation, Cu-based photocatalytic materials are widely integrated into S-scheme heterojunctions and exploited for the hydrogen evolution reaction (HER), CO2 reduction, H2O2 generation, N2 fixation, and pollutant degradation. This review comprehensively discusses recent progress in Cu-based S-scheme heterojunctions, and highlights their considerable potential for targeted applications in sustainable energy conversion, environmental remediation, and beyond. The fundamentals of S-scheme charge transfer, the design principles and verification tools are summarized. Then, the review describes the Cu-based photocatalytic materials, categorized according to their chemical composition, and their integration in S-scheme heterojunctions for photocatalytic applications. In particular, the implications of the S-scheme charge transfer mechanism on promoting the catalytic activity of selected systems are analyzed. Finally, current limitations and outlooks are provided to motivate future studies on developing novel and advanced Cu-based S-scheme photocatalysts with high performance and studying the underlying photocatalytic mechanisms.
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Affiliation(s)
- Mahmoud Sayed
- Laboratory of Solar Fuel, Faculty of Materials Science and Chemistry, China University of Geosciences, 68 Jincheng Road, Wuhan 430078, P. R. China.
- Chemistry department, Faculty of Science, Fayoum University, Fayoum 63514, Egypt
| | - Kezhen Qi
- College of Pharmacy, Dali University, Dali 671003, P. R. China
| | - Xinhe Wu
- Laboratory of Solar Fuel, Faculty of Materials Science and Chemistry, China University of Geosciences, 68 Jincheng Road, Wuhan 430078, P. R. China.
| | - Liuyang Zhang
- Laboratory of Solar Fuel, Faculty of Materials Science and Chemistry, China University of Geosciences, 68 Jincheng Road, Wuhan 430078, P. R. China.
| | - Hermenegildo García
- Department of Chemistry, Universitat Politècnica de València, 46022 Valencia, Spain.
| | - Jiaguo Yu
- Laboratory of Solar Fuel, Faculty of Materials Science and Chemistry, China University of Geosciences, 68 Jincheng Road, Wuhan 430078, P. R. China.
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Zhang R, Zhang B, Liu H, Jewell L, Liu X, Qiao S. Homo-Nuclear Hetero-Atomic Conjugated Reticular Oligomers for Heterojunction: A Novel "Electron Medium" for Panel Photoelectrocatalysis. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2407834. [PMID: 39429204 PMCID: PMC11633481 DOI: 10.1002/advs.202407834] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2024] [Revised: 09/29/2024] [Indexed: 10/22/2024]
Abstract
A substantial challenge in employing covalent organic frameworks (COFs) for photoelectrochemical (PEC) water splitting lies in improving their solution-processability while concurrently facilitating the transfer of charges and mass to the catalytic sites. Herein, we synthesize a solution-processable conjugated reticular oligomers (CROs), and further embed ruthenium (Ru) into the CRO, forming a CRO-Ru with homo-nuclear hetero-atomic. Thereafter, CRO and CRO-Ru construct an organic-organic heterojunction membrane at the nanoscale. This design achieves perfect lattice matching, significantly reducing the energy barrier of mass transfer, and effectively lowering the recombination rate of charge carriers. The optimized photocathode, CuI/CRO-Bpy:CRO-Bpy-Ru-1:1+P3HT/SnO2/Pt, exhibits an efficiency of 111.0 µA cm-2 at 0.4 V versus a reversible hydrogen electrode (RHE). Compared with the original bulk COFs and CROs, the efficiency is significantly improved. The apparent improvements in charge carrier separation and transfer are responsible for the high PEC activity. In the heterojunction, the incorporation of CRO-Bpy-Ru with a longer excited-state lifetime and a substantial built-in electric field has effectively accelerated the photo-induced electron transfer from the conduction band (CB) of CRO-Bpy to the valence band (VB) of CRO-Bpy-Ru, effectively suppressing the recombination of charges. These findings offer significant guidance for the design and optimization of high-performance photoelectrochemical catalysts.
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Affiliation(s)
- Ruijuan Zhang
- College of Chemistry and Pharmaceutical EngineeringHebei University of Science and TechnologyShijiazhuang050018China
- Institute for Catalysis and Energy SolutionsUniversity of South AfricaPrivate Bag X6Florida1710South Africa
| | - Boying Zhang
- College of Chemistry and Pharmaceutical EngineeringHebei University of Science and TechnologyShijiazhuang050018China
- Department of Chemical EngineeringFaculty of Engineering and the Built EnvironmentUniversity of JohannesburgDoornfontein2028South Africa
| | - Haining Liu
- College of Chemistry and Pharmaceutical EngineeringHebei University of Science and TechnologyShijiazhuang050018China
- Hebei Engineering Research Center of Organic Solid Photoelectric Materials for electronic informationShijiazhuang050018China
| | - Linda Jewell
- Institute for Catalysis and Energy SolutionsUniversity of South AfricaPrivate Bag X6Florida1710South Africa
| | - Xinying Liu
- Institute for Catalysis and Energy SolutionsUniversity of South AfricaPrivate Bag X6Florida1710South Africa
| | - Shanlin Qiao
- College of Chemistry and Pharmaceutical EngineeringHebei University of Science and TechnologyShijiazhuang050018China
- Hebei Engineering Research Center of Organic Solid Photoelectric Materials for electronic informationShijiazhuang050018China
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Singh RV, Pai MR, Banerjee AM, Shrivastava A, Kumar U, Sinha I, Dutta B, Hassan PA, Ningthoujam RS, Ghosh R, Nath S, Sharma RK, Jagannath, Bapat RD. Interfacial Engineering over Pt-Calcium Ferrite/2D Carbon Nitride Nanosheet p-n Heterojunctions for Superior Photocatalytic Properties. ACS OMEGA 2024; 9:40182-40203. [PMID: 39346866 PMCID: PMC11425653 DOI: 10.1021/acsomega.4c06353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2024] [Revised: 08/03/2024] [Accepted: 08/08/2024] [Indexed: 10/01/2024]
Abstract
The present study discloses the fabrication of efficient p-n heterojunctions using n-type polymeric bulk carbon nitride (b-CN, E g = 2.7 eV) or exfoliated nanosheets of carbon nitride (NSCN, E g = 2.9 eV) with p-type spinel ferrite CaFe2O4 (CFO, E g = 1.9 eV) for photocatalytic hydrogen generation. A series of p-n combinations were fabricated and characterized by various techniques. The oxide-carbon nitride interactions, light absorption, band alignment at the interface, and water/H3O+ adsorption capability were elucidated over heterojunctions and correlated with the photocatalytic hydrogen yield. The main developments in the present study are as follows: (1) All heterojunctions were more active than pure phases. (2) The photocatalytic activity trend validated an increase in the lifetime of charge carriers from TRPL. Pt(1 wt %)-CFO(1 wt %)/NSCN (481.5 μmol/h/g under ultraviolet (UV)-visible-simulated light, 147.5 μmol/h/g under CFL illumination for 20 h, τavg = 10.33 ns) > Pt-NSCN > Pt-CFO/b-CN > CFO/NSCN > CFO/b-CN > NSCN > Pt/b-CN > mechanical mixture (MM) of 1 wt %CFO + NSCN-MM > 1 wt %CFO + b-CN-MM > CFO > b-CN (τavg = 4.5 ns). (3) Pt-CFO/NSCN was most active and exhibited 250 times enhanced photocatalytic activity as compared to parent bulk carbon nitride, 6.5 times more active than CFO/NSCN, and twice more active than Pt-NSCN. Thus, enhanced activity is attributed to the smooth channelizing of electrons across p-n junctions. (4) NSCN evidently offered improved characteristics as a support and photocatalyst over b-CN. The exfoliated NSCN occupied a superior few-layer morphology with 0.35 nm width as compared to parent b-CN. NSCN allowed 57% dispersion of 6 nm-sized CFO, while b-CN supported 14% dispersion of 7.8 nm-sized CFO particles, as revealed by small-angle X-ray scattering spectroscopy (SAXS). Sizes of 2-4 nm were observed for Pt nanoparticles in the 1 wt %Pt/1 wt % CFO/NSCN sample. A binding energy shift and an increase in the FWHM of X-ray photoelectron spectroscopy (XPS) core level peaks established charge transfer and enhanced band bending on p-n contact in Pt-CFO/NSCN. FsTAS revealed the decay of photogenerated electrons via trapping in shallow traps (τ1, τ2) and deep traps (τ3). Lifetimes τ1 (3.19 ps, 42%) and τ2 (187 ps, 31%) were higher in NSCN than those in b-CN (τ1 = 2.2 ps, 42%, τ2 = 30 ps, 31%), which verified that the recombination reaction rate was suppressed by 6 times in NSCN (k 2 = 0.53 × 1010 s-1) as compared to b-CN (k 2 = 3.33 × 1010 s-1). Deep traps lie below the H+/H2 reduction potential; thus, electrons in deep traps are not available for photocatalytic H2 generation. (5) The role of CFO in enhancing water adsorption capability was modeled by molecular dynamics. NSCN or b-CN both showed very poor interaction with water molecules; however, the CFO cluster adsorbed H3O+ ions very strongly through the electrostatic interaction between calcium and oxygen (of H3O+). Pt also showed a strong affinity for H2O but not for H3O+. Thus, both CFO and Pt facilitated NSCN to access water molecules, and CFO further sustained the adsorption of H3O+ molecules, crucial for the photocatalytic reduction of water molecules. (6) Band potentials of CFO and NSCN aligned suitably at the interface of CFO/NSCN, resulting in a type-II band structure. Valence band offset (VBO, ΔE VB) and conduction band offset (CBO, ΔE CB) were calculated at the interface, resulting in an effective band gap of 1.41 eV (2.9 - ΔE VB = 1.9 - ΔE CB), much lower than parent compounds. The interfacial band structure was efficient in driving photogenerated electrons from the CB of CFO to the CB of NSCN and holes from the VB of NSCN to the VB of CFO, thus successfully separating charge carriers, as supported by the increased lifetime of charge carriers and favorable photocatalytic H2 yield.
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Affiliation(s)
- Rajendra V Singh
- Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400085, India
| | - Mrinal R Pai
- Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400085, India
| | - Atindra M Banerjee
- Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400085, India
| | - Anshu Shrivastava
- Department of Chemistry, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005, India
| | - Uttam Kumar
- Department of Chemistry, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005, India
| | - Indrajit Sinha
- Department of Chemistry, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005, India
| | - Bijaideep Dutta
- Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - Puthusserickal A Hassan
- Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400085, India
| | - Raghumani S Ningthoujam
- Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400085, India
| | - Rajib Ghosh
- Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - Sukhendu Nath
- Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400085, India
| | - Rajendra K Sharma
- Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - Jagannath
- Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - Rudheer D Bapat
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Colaba, Mumbai 400005, India
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Wang W, Zhou T, Yang Y, Du L, Xia R, Shang C, Phillips DL, Guo Z. Sub-Band Assisted Z-Scheme for Effective Non-Sacrificial H 2O 2 Photosynthesis. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2312022. [PMID: 38698610 DOI: 10.1002/smll.202312022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 03/07/2024] [Indexed: 05/05/2024]
Abstract
Photosynthesis of H2O2 from earth-abundant O2 and H2O molecules offers an eco-friendly route for solar-to-chemical conversion. The persistent challenge is to tune the photo-/thermo- dynamics of a photocatalyst toward efficient electron-hole separation while maintaining an effective driving force for charge transfer. Such a case is achieved here by way of a synergetic strategy of sub-band-assisted Z-Scheme for effective H2O2 photosynthesis via direct O2 reduction and H2O oxidation without a sacrificial agent. The optimized SnS2/g-C3N4 heterojunction shows a high reactivity of 623.0 µmol g-1 h-1 for H2O2 production under visible-light irradiation (λ > 400 nm) in pure water, ≈6 times higher than pristine g-C3N4 (100.5 µmol g-1 h-1). Photodynamic characterizations and theoretical calculations reveal that the enhanced photoactivity is due to a markedly promoted lifetime of trapped active electrons (204.9 ps in the sub-band and >2.0 ns in a shallow band) and highly improved O2 activation, as a result of the formation of a suitable sub-band and catalytic sites along with a low Gibbs-free energy for charge transfer. Moreover, the Z-Scheme heterojunction creates and sustains a large driving force for O2 and H2O conversion to high value-added H2O2.
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Affiliation(s)
- Wenchao Wang
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR, 999077, P. R. China
- School of New Energy, Nanjing University of Science & Technology, Jiangyin, 214443, P. R. China
| | - Tao Zhou
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR, 999077, P. R. China
| | - Yuchen Yang
- Zhejiang Institute of Research and Innovation, The University of Hong Kong, Hangzhou, 311305, P. R. China
| | - Lili Du
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR, 999077, P. R. China
| | - Ruiqin Xia
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR, 999077, P. R. China
| | - Congxiao Shang
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR, 999077, P. R. China
| | - David Lee Phillips
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR, 999077, P. R. China
| | - Zhengxiao Guo
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, SAR, 999077, P. R. China
- Zhejiang Institute of Research and Innovation, The University of Hong Kong, Hangzhou, 311305, P. R. China
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5
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Kumar A, Singh P, Nguyen VH, Le QV, Ahamad T, Thakur S, Matsagar BM, Kaya S, Maslov MM, Wu KCW, Nguyen LH, Raizada P. DFT and experimental studies of the facet-dependent oxygen vacancies modulated WS 2/BiOCl-OV S-scheme structure for enhanced photocatalytic removal of ciprofloxacin from wastewater. ENVIRONMENTAL RESEARCH 2024; 250:118519. [PMID: 38382660 DOI: 10.1016/j.envres.2024.118519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 02/09/2024] [Accepted: 02/17/2024] [Indexed: 02/23/2024]
Abstract
The present study explores visible light-assisted photodegradation of ciprofloxacin hydrochloride (CIP) antibiotic as a promising solution to water pollution. The focus is on transforming the optical and electronic properties of BiOCl through the generation of oxygen vacancies (OVs) and the exposure of (110) facets, forming a robust S-scheme heterojunction with WS2. The resultant OVs mediated composite with an optimal ratio of WS2 and BiOCl-OV (4-WS2/BiOCl-OV) demonstrated remarkable efficiency (94.3%) in the visible light-assisted photodegradation of CIP antibiotic within 1.5 h. The CIP degradation using 4-WS2/BiOCl-OV followed pseudo-first-order kinetics with the rate constant of 0.023 min-1, outperforming bare WS2, BiOCl, and BiOCl-OV by 8, 6, and 4 times, respectively. Density functional theory (DFT) analysis aligned well with experimental results, providing insights into the structural arrangement and bandgap analysis of the photocatalysts. Liquid chromatography-mass spectrometry (LC-MS) analysis utilized for identifying potentially degraded products while scavenging experiments and electron paramagnetic resonance (EPR) spin trapping analysis elucidated the S-scheme charge transfer mechanism. This research contributes to advancing the design of oxygen vacancy-mediated S-scheme systems in the realm of photocatalysis, with potential implications for addressing water pollution concerns.
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Affiliation(s)
- Abhinandan Kumar
- School of Advanced Chemical Sciences, Shoolini University, Solan, Himachal Pradesh, 173212, India
| | - Pardeep Singh
- School of Advanced Chemical Sciences, Shoolini University, Solan, Himachal Pradesh, 173212, India
| | - Van-Huy Nguyen
- Centre for Herbal Pharmacology and Environmental Sustainability, Chettinad Hospital and Research Institute, Chettinad Academy of Research and Education, Kelambakkam, 603103, Tamil Nadu, India.
| | - Quyet Van Le
- Department of Materials Science and Engineering, Korea University, 145, Anamro, Seongbuk-gu, Seoul, 02841, Republic of Korea
| | - Tansir Ahamad
- Department of Chemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Sourbh Thakur
- Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Silesian University of Technology, B. Krzywoustego 4, 44-100, Gliwice, Poland
| | - Babasaheb M Matsagar
- Department of Chemical Engineering, National Taiwan University (NTU), No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Savas Kaya
- Department of Chemistry, Faculty of Science, Sivas Cumhuriyet University, 58140, Sivas, Turkey
| | - Mikhail M Maslov
- Nanoengineering in Electronics, Spintronics and Photonics Institute, National Research Nuclear University "MEPhI", Kashirskoe Shosse 31, Moscow, 115409, Russia
| | - Kevin C-W Wu
- Department of Chemical Engineering, National Taiwan University (NTU), No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan
| | - Lan Huong Nguyen
- Faculty of Biology and Environment, Ho Chi Minh City University of Industry and Trade (HUIT), 140 Le Trong Tan Street, Tay Thanh Ward, Tan Phu District, Ho Chi Minh City, Viet Nam
| | - Pankaj Raizada
- School of Advanced Chemical Sciences, Shoolini University, Solan, Himachal Pradesh, 173212, India.
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Fang Y, Yang H, Hou Y, Li W, Shen Y, Liu S, Zhang Y. Timescale correlation of shallow trap states increases electrochemiluminescence efficiency in carbon nitrides. Nat Commun 2024; 15:3597. [PMID: 38678039 PMCID: PMC11519465 DOI: 10.1038/s41467-024-48011-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 04/18/2024] [Indexed: 04/29/2024] Open
Abstract
Highly efficient interconversion of different types of energy plays a crucial role in both science and technology. Among them, electrochemiluminescence, an emission of light excited by electrochemical reactions, has drawn attention as a powerful tool for bioassays. Nonetheless, the large differences in timescale among diverse charge-transfer pathways from picoseconds to seconds significantly limit the electrochemiluminescence efficiency and hamper their broad applications. Here, we report a timescale coordination strategy to improve the electrochemiluminescence efficiency of carbon nitrides by engineering shallow electron trap states via Au-N bond functionalization. Quantitative electrochemiluminescence kinetics measurements and theoretic calculations jointly disclose that Au-N bonds endow shallow electron trap states, which coordinate the timescale of the fast electron transfer in the bulk emitter and the slow redox reaction of co-reagent at diffusion layers. The shallow electron trap states ultimately accelerate the rate and kinetics of emissive electron-hole recombination, setting a new cathodic electrochemiluminescence efficiency record of carbon nitrides, and empowering a visual electrochemiluminescence sensor for nitrite ion, a typical environmental contaminant, with superior detection range and limit.
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Affiliation(s)
- Yanfeng Fang
- Jiangsu Engineering Research Center for Carbon-Rich Materials and Devices, Jiangsu Province Hi-Tech Key Laboratory for Bio-Medical Research, School of Chemistry and Chemical Engineering, Nanjing, 211189, China
| | - Hong Yang
- Jiangsu Engineering Research Center for Carbon-Rich Materials and Devices, Jiangsu Province Hi-Tech Key Laboratory for Bio-Medical Research, School of Chemistry and Chemical Engineering, Nanjing, 211189, China
| | - Yuhua Hou
- Jiangsu Engineering Research Center for Carbon-Rich Materials and Devices, Jiangsu Province Hi-Tech Key Laboratory for Bio-Medical Research, School of Chemistry and Chemical Engineering, Nanjing, 211189, China
| | - Wang Li
- Jiangsu Engineering Research Center for Carbon-Rich Materials and Devices, Jiangsu Province Hi-Tech Key Laboratory for Bio-Medical Research, School of Chemistry and Chemical Engineering, Nanjing, 211189, China
| | - Yanfei Shen
- Medical School, Southeast University, Nanjing, 210009, China.
| | - Songqin Liu
- Jiangsu Engineering Research Center for Carbon-Rich Materials and Devices, Jiangsu Province Hi-Tech Key Laboratory for Bio-Medical Research, School of Chemistry and Chemical Engineering, Nanjing, 211189, China
| | - Yuanjian Zhang
- Jiangsu Engineering Research Center for Carbon-Rich Materials and Devices, Jiangsu Province Hi-Tech Key Laboratory for Bio-Medical Research, School of Chemistry and Chemical Engineering, Nanjing, 211189, China.
- Department of Oncology, Zhongda Hospital, Southeast University, Nanjing, 210009, China.
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7
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Xue J, Fujitsuka M, Tachikawa T, Bao J, Majima T. Charge Trapping in Semiconductor Photocatalysts: A Time- and Space-Domain Perspective. J Am Chem Soc 2024; 146:8787-8799. [PMID: 38520348 DOI: 10.1021/jacs.3c14757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/25/2024]
Abstract
Harnessing solar energy to produce value-added fuels and chemicals through photocatalysis techniques holds promise for establishing a sustainable and environmentally friendly energy economy. The intricate dynamics of photogenerated charge carriers lies at the core of the photocatalysis. The balance between charge trapping and band-edge recombination has a crucial influence on the activity of semiconductor photocatalysts. Consequently, the regulation of traps in photocatalysts becomes the key to optimizing their activities. Nevertheless, our comprehension of charge trapping, compared to that of well-studied charge recombination, remains somewhat limited. This limitation stems from the inherently heterogeneous nature of traps at both temporal and spatial scales, which renders the characterization of charge trapping a formidable challenge. Fortunately, recent advancements in both time-resolved spectroscopy and space-resolved microscopy have paved the way for considerable progress in the investigation and manipulation of charge trapping. In this Perspective, we focus on charge trapping in photocatalysts with the aim of establishing a direct link to their photocatalytic activities. To achieve this, we begin by elucidating the principles of advanced time-resolved spectroscopic techniques such as femtosecond time-resolved transient absorption spectroscopy and space-resolved microscopic methods, such as single-molecule fluorescence microscopy and surface photovoltage microscopy. Additionally, we provide an overview of noteworthy research endeavors dedicated to probing charge trapping using time- and space-resolved techniques. Our attention is then directed toward recent achievements in the manipulation of charge trapping in photocatalysts through defect engineering. Finally, we summarize this Perspective and discuss the future challenges and opportunities that lie ahead in the field.
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Affiliation(s)
- Jiawei Xue
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Mamoru Fujitsuka
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
| | - Takashi Tachikawa
- Department of Chemistry, Graduate School of Science and Molecular Photoscience Research Center, Kobe University, Kobe 657-8501, Japan
| | - Jun Bao
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, China
- iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), University of Science and Technology of China, Hefei, Anhui 230029, China
- Key Laboratory of Precision and Intelligent Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Tetsuro Majima
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan
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Liu Y, Li HY, Cao HX, Zheng XY, Yin Shi B, Yin HT. Defect and interface/surface engineering synergistically modulated electron transfer and nonlinear absorption properties in MoX 2 (X = Se, S, Te)@ZnO heterojunction. NANOSCALE 2024; 16:1865-1879. [PMID: 38168696 DOI: 10.1039/d3nr05766f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Systematic interface and defect engineering strategies have been demonstrated to be an effective way to modulate the electron transfer and nonlinear absorption properties in semiconductor heterojunctions. However, the role played by defects and interfacial strain in electron transfer at the interface of the MoX2 (X = Se, S, Te)@ZnO heterojunction remains poorly understood. Herein, using the MoX2@ZnO heterojunction, we reveal that vacancies play a critical role in the interfacial electron transfer of heterojunctions. Specifically, we present the defect and interface engineering of the MoX2@ZnO heterojunction for controlled charge transfer and electron excitation-relaxation. The experimental characterization combined with first-principles calculations showed that the presence of defects promoted the transport of photogenerated carriers at the heterojunction interface, thereby inhibiting their rapid recombination. The DFT calculation confirmed that the electron band structure, density of states and charge density distribution in the system changed after the formation of Mo-O bonds. On the basis of defects and interfacial stress and the effective charge transfer, the MoX2@ZnO heterojunction exhibited excellent excitation and emission behaviors. The nonlinear optical regulation behavior of TMDs is expected to be realized with the help of the defects and interface/surface synergistically modulated effect of ZnO nanoparticles. The local strain generation on the MoX2@ZnO heterojunction boundary provides a new method for the design of new heterogeneous materials and will be of great significance to investigate the contact physical behavior and application of metals and two-dimensional (2D) semiconductors. This work provides some inspiration for the construction of heterojunctions with rich defects and surface/interface charge transfer channels to promote tunable electron transfer dynamics, thereby achieving a good nonlinear optical conversion efficiency and efficient charge separation in optoelectronic functional materials.
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Affiliation(s)
- Yu Liu
- Key Laboratory of Photonic and electric Bandgap materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin, 150025, Heilongjiang Province, China.
| | - Hong-Yu Li
- Key Laboratory of Photonic and electric Bandgap materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin, 150025, Heilongjiang Province, China.
| | - Hong-Xu Cao
- Key Laboratory of Photonic and electric Bandgap materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin, 150025, Heilongjiang Province, China.
| | - Xin-Yu Zheng
- Key Laboratory of Photonic and electric Bandgap materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin, 150025, Heilongjiang Province, China.
| | - Bing- Yin Shi
- Key Laboratory of Photonic and electric Bandgap materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin, 150025, Heilongjiang Province, China.
| | - Hai-Tao Yin
- Key Laboratory of Photonic and electric Bandgap materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin, 150025, Heilongjiang Province, China.
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9
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Zheng XY, Li HY, Shi BY, Cao HX, Liu Y, Yin HT. Study on interface engineering and chemical bonding of the ReS 2@ZnO heterointerface for efficient charge transfer and nonlinear optical conversion efficiency. Phys Chem Chem Phys 2024; 26:3008-3019. [PMID: 38179673 DOI: 10.1039/d3cp04775j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
Rhenium sulfide (ReS2) has emerged as a promising two-dimensional material, demonstrating broad-spectrum visible absorption properties that make it highly relevant for diverse optoelectronic applications. Manipulating and optimizing the pathway of photogenerated carriers play a pivotal role in enhancing the efficiency of charge separation and transfer in novel semiconductor composites. This study focuses on the strategic construction of a semiconductor heterostructure by synthesizing ZnO on vacancy-containing ReS2 (VRe-ReS2) through chemical bonding processes. The ingeniously engineered built-in electric field within the heterostructure effectively suppresses the recombination of photogenerated electron-hole pairs. A direct and well-established interfacial connection between VRe-ReS2 and ZnO is achieved through a robust Zn-S bond. This distinctive bond configuration leads to enhanced nonlinear optical conversion efficiency, attributed to shortened carrier migration distances and accelerated charge transfer rates. Furthermore, theoretical calculations unveil the superior chemical interactions between Re vacancies and sulfide moieties, facilitating the formation of Zn-S bonds. The photoluminescence (PL) intensity is increased by the formation of VRe-ReS2 and ZnO heterostructure and the PL quantum yield of VRe-ReS2 is improved. The intricate impact of the Zn-S bond on the nonlinear absorption behavior of the VRe-ReS2@ZnO heterostructure is systematically investigated using femtosecond Z-scan techniques. The charge transfer from ZnO to ReS2 defect levels induces a transition from saturable absorption to reverse saturable absorption in the VRe-ReS2@ZnO heterostructure. Transient absorption measurements further confirm the presence of the Zn-S bond between the interfaces, as evidenced by the prolonged relaxation time (τ3) in the VRe-ReS2@ZnO heterostructure. This study offers valuable insights into the rational construction of heterojunctions through tailored interfacial bonding and surface/interface charge transfer pathways. These endeavors facilitate the modulation of electron transfer dynamics, ultimately yielding superior nonlinear optical conversion efficiency and effective charge regulation in optoelectronic functional materials.
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Affiliation(s)
- Xin-Yu Zheng
- Key Laboratory of Photonic and electric Bandgap materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin, 150025, Heilongjiang Province, China.
| | - Hong-Yu Li
- Key Laboratory of Photonic and electric Bandgap materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin, 150025, Heilongjiang Province, China.
| | - Bing-Yin Shi
- Key Laboratory of Photonic and electric Bandgap materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin, 150025, Heilongjiang Province, China.
| | - Hong-Xu Cao
- Key Laboratory of Photonic and electric Bandgap materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin, 150025, Heilongjiang Province, China.
| | - Yu Liu
- Key Laboratory of Photonic and electric Bandgap materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin, 150025, Heilongjiang Province, China.
| | - Hai-Tao Yin
- Key Laboratory of Photonic and electric Bandgap materials, Ministry of Education, School of Physics and Electronic Engineering, Harbin Normal University, Harbin, 150025, Heilongjiang Province, China.
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10
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Rezaei M, Nezamzadeh-Ejhieh A, Massah AR. A comprehensive review on the boosted effects of anion vacancy in the heterogeneous photocatalytic degradation, part I: Focus on sulfur, nitrogen, carbon, and halogen vacancies. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 269:115927. [PMID: 38181561 DOI: 10.1016/j.ecoenv.2024.115927] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 11/07/2023] [Accepted: 01/01/2024] [Indexed: 01/07/2024]
Abstract
The greenest environmental remediation way is the photocatalytic degradation of organic pollutants. However, limited photocatalytic applications are due to poor sunlight absorption and photogenerated charge carriers' recombination. These limitations can be overcome by introducing anion vacancy (AV) (O, S, N, C, and Halogen) defects in semiconductors that enhance light harvesting, facilitate charge separation, modulate electronic structure, and produce reactive radicals. In continuing part A of this review, in this part, we summarized the recent AVs' research, including S, N, C, and halogen vacancies on the boosted photocatalytic features of semiconductor materials, like metal oxides/sulfides, oxyhalides, and nitrides in detail. Also, we outline the recently developed AV designs for the photocatalytic degradation of organic pollutants. The AV creating and analysis methods and the recent photocatalytic applications and mechanisms of AV-mediated photocatalysts are reviewed. AV engineering photocatalysts' challenges and development prospects are illustrated to get a promising research direction.
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Affiliation(s)
- Mahdieh Rezaei
- Department of Chemistry, Shahreza Branch, Islamic Azad University, P.O. Box 311-86145, Shahreza, Isfahan, Iran
| | - Alireza Nezamzadeh-Ejhieh
- Department of Chemistry, Shahreza Branch, Islamic Azad University, P.O. Box 311-86145, Shahreza, Isfahan, Iran; Department of Chemistry, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran.
| | - Ahmad Reza Massah
- Department of Chemistry, Shahreza Branch, Islamic Azad University, P.O. Box 311-86145, Shahreza, Isfahan, Iran; Department of Chemistry, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran
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11
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Yuan C, Yin H, Lv H, Zhang Y, Li J, Xiao D, Yang X, Zhang Y, Zhang P. Defect and Donor Manipulated Highly Efficient Electron-Hole Separation in a 3D Nanoporous Schottky Heterojunction. JACS AU 2023; 3:3127-3140. [PMID: 38034977 PMCID: PMC10685433 DOI: 10.1021/jacsau.3c00482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 09/29/2023] [Accepted: 10/03/2023] [Indexed: 12/02/2023]
Abstract
Given the rapid recombination of photogenerated charge carriers and photocorrosion, transition metal sulfide photocatalysts usually suffer from modest photocatalytic performance. Herein, S-vacancy-rich ZnIn2S4 (VS-ZIS) nanosheets are integrated on 3D bicontinuous nitrogen-doped nanoporous graphene (N-npG), forming 3D heterostructures with well-fitted geometric configuration (VS-ZIS/N-npG) for highly efficient photocatalytic hydrogen production. The VS-ZIS/N-npG presents ultrafast interfacial photogenerated electrons captured by the S vacancies in VS-ZIS and holes neutralization behaviors by the extra free electrons in N-npG during photocatalysis, which are demonstrated by in situ XPS, femtosecond transient absorption (fs-TA) spectroscopy, and transient-state surface photovoltage (TS-SPV) spectra. The simulated interfacial charge rearrangement behaviors from DFT calculations also verify the separation tendency of photogenerated charge carriers. Thus, the optimized VS-ZIS/N-npG 3D hierarchical heterojunction with 1.0 wt % N-npG exhibits a comparably high hydrogen generation rate of 4222.4 μmol g-1 h-1, which is 5.6-fold higher than the bare VS-ZIS and 12.7-fold higher than the ZIS without S vacancies. This work sheds light on the rational design of photogenerated carrier transfer paths to facilitate charge separation and provides further hints for the design of hierarchical heterostructure photocatalysts.
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Affiliation(s)
- Chunyu Yuan
- School
of Physics and Physical Engineering, Qufu
Normal University, Qufu 273165, China
| | - Hongfei Yin
- School
of Physics and Physical Engineering, Qufu
Normal University, Qufu 273165, China
| | - Huijun Lv
- School
of Physics and Physical Engineering, Qufu
Normal University, Qufu 273165, China
| | - Yujin Zhang
- School
of Physics and Physical Engineering, Qufu
Normal University, Qufu 273165, China
| | - Jing Li
- Key
Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese
Academy of Sciences, Beijing 100190, China
| | - Dongdong Xiao
- Institute
of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xiaoyong Yang
- School
of Physics and Physical Engineering, Qufu
Normal University, Qufu 273165, China
- Condensed
Matter Theory Group, Materials Theory Division, Department of Physics
and Astronomy, Uppsala University, Box 516, 75120 Uppsala, Sweden
| | - Yongzheng Zhang
- School
of Physics and Physical Engineering, Qufu
Normal University, Qufu 273165, China
| | - Ping Zhang
- School
of Physics and Physical Engineering, Qufu
Normal University, Qufu 273165, China
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12
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Rawool SA, Pai MR, Banerjee AM, Nath S, Bapat RD, Sharma RK, Jagannath, Dutta B, Hassan PA, Tripathi AK. Superior Interfacial Contact Yields Efficient Electron Transfer Rate and Enhanced Solar Photocatalytic Hydrogen Generation in M/C 3N 4 Schottky Junctions. ACS APPLIED MATERIALS & INTERFACES 2023; 15:39926-39945. [PMID: 37556210 DOI: 10.1021/acsami.3c05833] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/11/2023]
Abstract
Various literature studies (Table 6) have reported that dispersion of metal nanoparticles (NPs) on graphitic carbon nitride g-C3N4 (M/CN) has considerably improved the photocatalytic hydrogen yield. It is understood that metal NPs create active sites on the surface of CN and act as a cocatalyst. However, the precise changes induced by different metal NPs on the surface of CN still elude us. Here, we report a thorough understanding and comparison of the morphology, metal-support interactions, interfacial charge transfer kinetics, and band characteristics in different M/CN (M = Pt, Pd, Au, Ag, Cu) correlated with photocatalytic activity. Among all metals, Pt/CN was found to be the best performer both under sunlight and UV-visible irradiation. Under sunlight, maximum H2@ 2.7 mmol/h/g was observed over Pt/CN followed by Pd/CN > Au/CN > Ag/CN > Cu/CN ≈ CN. The present study revealed that among all metals, Pt formed superior interfacial contact with g-C3N4 as compared to other metals. The maximum Schottky barrier height (Φb,Pt) of 0.66 V was observed at Pt/CN followed by Φb,Au/CN (0.46 V) and Φb,Pd/CN (0.05 V). The presence of electron-deficient Pt in Pt-XPS, decrease in the intensity of d-DOS of Pt near the Fermi level in VB-XPS, increase in CB tail states, and cathodic shift in Vfb in MS plots sufficiently confirmed strong metal-support interactions in Pt/CN. Due to the SPR effect, Au and Ag NPs suffered from agglomeration and poor dispersion during photodeposition. Finely dispersed Pt NPs (2-4 nm, 53% dispersion) successfully competed with shallow/deep trap states and drove the photogenerated electrons to active metallic sites in a drastically reduced time period as investigated by femtosecond transient absorption spectroscopy. Typically, an interfacial electron transfer rate, KIET,avg, of 2.5 × 1010 s-1 was observed for Pt/CN, while 0.087 × 1010 s-1 was observed in Au/CN. Band alignment/potentials at M/CN Schottky junctions were derived and most favorable in Pt/CN with CB tail states much above the water reduction potential; however, in the case of Pd, these extend much below the H+/H2 potential and hence behave like deep trap states. Thus, in Pd/CN (τ0 = 4200 ps, 49%) and Ag/CN (3870 ps, 53%), electron deep trapping dominates over charge transfer to active sites. The present study will help in designing futuristic new cocatalyst-photocatalyst systems.
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Affiliation(s)
- Sushma A Rawool
- Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, Maharashtra India
| | - Mrinal R Pai
- Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, Maharashtra India
| | - A M Banerjee
- Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, Maharashtra India
| | - S Nath
- Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, Maharashtra India
| | - R D Bapat
- Department of Condensed Matter Physics and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, Maharashtra India
| | - R K Sharma
- Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India
| | - Jagannath
- Technical Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra, India
| | - B Dutta
- Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra India
| | - P A Hassan
- Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, Maharashtra India
| | - A K Tripathi
- Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, Maharashtra India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, Maharashtra India
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13
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Shen R, Liang G, Hao L, Zhang P, Li X. In Situ Synthesis of Chemically Bonded 2D/2D Covalent Organic Frameworks/O-Vacancy WO 3 Z-Scheme Heterostructure for Photocatalytic Overall Water Splitting. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2303649. [PMID: 37319036 DOI: 10.1002/adma.202303649] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 05/29/2023] [Indexed: 06/17/2023]
Abstract
Covalent organic frameworks (COFs) have shown great promise for photocatalytic hydrogen evolution via water splitting. However, the four-electron oxidation of water remains elusive toward oxygen evolution. Enabling this water oxidation pathway is critical to improve the yield and maximize atom utilization efficiency. A Z-scheme heterojunction is proposed for overcoming fundamental issues in COF-based photocatalytic overall water splitting (OWS), such as inefficient light absorption, charge recombination, and poor water oxidation ability. It is shown that the construction of a novel 2D/2D Z-scheme heterojunction through in situ growth of COFs on the O-vacancy WO3 nanosheets (Ov-WO3 ) via the WOC chemical bond can remarkably promote photocatalytic OWS. Benefiting from the synergistic effect between the enhanced built-in electric field by the interfacial WOC bond, the strong water oxidation ability of Ov-WO3, and the ultrathin structure of TSCOF, both separation and utilization efficiency of photogenerated electron-hole pairs can be significantly enhanced. An impressive photocatalytic hydrogen evolution half-rection rate of 593 mmol h-1 g-1 and overall water splitting rate of 146 (hydrogen) and 68 (oxygen) µmol h-1 g-1 are achieved on the COF-WO3 (TSCOFW) composite. This 2D/2D Z-scheme heterojunction with two-step excitation and precisely cascaded charge-transfer pathway makes it responsible for the efficient solar-driven OWS without a sacrificial agent.
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Affiliation(s)
- Rongchen Shen
- Institute of Biomass Engineering, Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, 510642, P. R. China
| | - Guijie Liang
- Hubei Key Lab Low Dimens Optoelect Mat & Devices, Hubei University of Arts and Science, Xiangyang, 441053, P. R. China
| | - Lei Hao
- Institute of Biomass Engineering, Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, 510642, P. R. China
| | - Peng Zhang
- State Centre for International Cooperation on Designer Low-Carbon & Environmental Materials (CDLCEM), School of Materials Science and Engineering, Zhengzhou University, Zhengzhou, Henan, 450001, P. R. China
| | - Xin Li
- Institute of Biomass Engineering, Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, 510642, P. R. China
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14
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Gai Q, Ren S, Zheng X, Liu W. Enhanced plasmonic photocatalytic performance of C 3N 4/Cu by the introduction of a reduced graphene oxide interlayer. Phys Chem Chem Phys 2023; 25:12754-12766. [PMID: 37128700 DOI: 10.1039/d3cp01118f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Cu nanoparticles (NPs) are low-cost surface plasmonic resonance (SPR) metal nanostructures, and their SPR properties can be used to enhance the photocatalytic hydrogen evolution performance of carbon nitride (C3N4). But their actual performance is usually limited, and one key factor is their poor interfacial quality. In this work, a highly conductive reduced graphene oxide (RGO) interlayer is introduced between protonated C3N4 (PCN) nanosheets and Cu NPs, which can act as an efficient sink for photogenerated electrons from C3N4 and hot electrons from Cu NPs, and simultaneously serve as reaction sites for the hydrogen evolution reaction, and accelerate the charge transport by the formed C-O-C and C-O-Cu bonds. The optimal hydrogen evolution rate of the optimized PCN/RGO/Cu is 1.30 mmol g-1 h-1, which is 6.76, 2.47 and 2.41 times that of PCN, PCN/RGO and PCN/Cu, respectively, and it can further reach up to 13.22 mmol g-1 h-1 by loading moderate Pt NPs. Meanwhile, the introduced RGO can effectively anchor Cu NPs to enhance the stability of the photocatalyst. In addition, due to the broad SPR response of Cu NPs, a near-infrared photocatalytic performance is realized for PCN/RGO/Cu with an apparent quantum efficiency of 0.46% at 765 nm.
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Affiliation(s)
- Qixiao Gai
- Department of Optoelectronic Science, Harbin Institute of Technology at Weihai, Weihai 264209, P. R. China.
- Department of Physics, Harbin Institute of Technology, Harbin 150001, P. R. China
| | - Shoutian Ren
- Department of Optoelectronic Science, Harbin Institute of Technology at Weihai, Weihai 264209, P. R. China.
| | - Xiaochun Zheng
- Department of Optoelectronic Science, Harbin Institute of Technology at Weihai, Weihai 264209, P. R. China.
- Department of Physics, Harbin Institute of Technology, Harbin 150001, P. R. China
| | - Wenjun Liu
- Department of Optoelectronic Science, Harbin Institute of Technology at Weihai, Weihai 264209, P. R. China.
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15
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Ultralow–biased solar photoelectrochemical hydrogen generation by Ag2S/ZnO heterojunction with high efficiency. J Taiwan Inst Chem Eng 2022. [DOI: 10.1016/j.jtice.2022.104554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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16
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Xu Y, Wang M, Liu Y, Yu R, Xu Q, Meng S, Jiang D, Chen M. Efficient charge transfer in Co-doped CeO 2/graphitic carbon nitride with N vacancies heterojunction for photocatalytic hydrogen evolution. J Colloid Interface Sci 2022; 627:261-269. [PMID: 35849859 DOI: 10.1016/j.jcis.2022.07.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 07/04/2022] [Accepted: 07/07/2022] [Indexed: 10/17/2022]
Abstract
Photocatalytic hydrogen evolution is a promising and environmentally friendly strategy to prepare renewable energy sources thus addressing the energy crisis and environmental issues, and it is crucial to develop an ideal photocatalytic for highly efficient H2 production. Herein, the Co-doped CeO2 decorated on graphitic carbon nitride with N vacancies (NVs) heterostructure photocatalyst (Co-CeO2/DCN) is prepared via a simple self-assembly method. Due to the extended light absorption range, and efficient charge separation and migration derived from the introduction of NVs and the heterojunction structure, the photocatalytic activity of the Co-CeO2/DCN is largely promoted. The optimal sample 20-Co-CeO2/DCN shows a high H2 evolution rate of 1077.02 μmol g-1h-1 (λ > 400 nm), which is 113 and 33 times higher than the bare bulk graphitic carbon nitride (BCN) and CeO2, respectively. This work will provide a new strategy to develop high-performance photocatalysts using defect engineering and heterojunction engineering for H2 evolution.
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Affiliation(s)
- Yuyan Xu
- School of Chemistry and Chemical Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang 212013, China
| | - Mengqi Wang
- School of Chemistry and Chemical Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang 212013, China
| | - Ying Liu
- School of Chemistry and Chemical Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang 212013, China
| | - Rui Yu
- School of Chemistry and Chemical Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang 212013, China
| | - Qing Xu
- School of Chemistry and Chemical Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang 212013, China
| | - Suci Meng
- School of Chemistry and Chemical Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang 212013, China
| | - Deli Jiang
- School of Chemistry and Chemical Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang 212013, China
| | - Min Chen
- School of Chemistry and Chemical Engineering, Jiangsu University, Xuefu Road 301, Zhenjiang 212013, China.
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17
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Gai Q, Ren S, Zheng X, Liu W, Dong Q. Optimized hot electron injection from Cu nanoparticles to S-doped C 3N 4 by the formed S-Cu bonds for an enhanced photocatalytic performance. Phys Chem Chem Phys 2022; 24:7521-7530. [PMID: 35289814 DOI: 10.1039/d1cp05743j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Low-cost and high-abundance Cu nanostructures are potential near-infrared (NIR) surface plasmonic resonance (SPR) photosensitizers for carbon nitride (C3N4) photocatalysts, but their low activity and stability need to be improved. In this article, doping S into C3N4 (S-C3N4) creates anchoring sites for photo-deposited Cu nanoparticles (NPs), and the spontaneous construction of S-Cu bonds is realized between S-C3N4 and Cu NPs. The optimal hydrogen evolution rate of 1.64 mmol g-1 h-1 is obtained for S-C3N4-Cu, which is 5.5, 4.6 and 1.7 times that of pure C3N4, S-C3N4 and S-C3N4-Cu, respectively. With further loading of a Pt co-catalyst to confirm the role of Cu NPs and improve the photocatalytic activity of the SCN-Cu, the photocatalytic rate can reach up to 14.34 mmol g-1 h-1. Due to the NIR SPR effect of Cu NPs, the apparent quantum efficiency (AQE) of S-C3N4-Cu at 600 and 765 nm is 2.02% and 0.47%, respectively. The enhanced photocatalytic performance of S-C3N4-Cu compared with C3N4-Cu is mainly due to the introduced S-Cu bonds that improve the injection rate of hot electrons. This solution provides a simple and efficient interface optimization strategy for the construction of efficient NIR-driven photocatalysts.
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Affiliation(s)
- Qixiao Gai
- Department of Optoelectronic Science, Harbin Institute of Technology at Weihai, Weihai 264209, People's Republic of China. .,Department of Physics, Harbin Institute of Technology, Harbin 150001, People's Republic of China
| | - Shoutian Ren
- Department of Optoelectronic Science, Harbin Institute of Technology at Weihai, Weihai 264209, People's Republic of China.
| | - Xiaochun Zheng
- Department of Optoelectronic Science, Harbin Institute of Technology at Weihai, Weihai 264209, People's Republic of China. .,Department of Physics, Harbin Institute of Technology, Harbin 150001, People's Republic of China
| | - Wenjun Liu
- Department of Optoelectronic Science, Harbin Institute of Technology at Weihai, Weihai 264209, People's Republic of China.
| | - Quanli Dong
- Department of Optoelectronic Science, Harbin Institute of Technology at Weihai, Weihai 264209, People's Republic of China.
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18
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Goswami T, Bhatt H, Yadav DK, Ghosh HN. Interfacing g-C 3N 4 Nanosheets with CdS Nanorods for Enhanced Photocatalytic Hydrogen Evolution: An Ultrafast Investigation. J Phys Chem B 2022; 126:572-580. [PMID: 34994569 DOI: 10.1021/acs.jpcb.1c10336] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Effective separation of electron-hole and utilization of hot charge carriers are known to be the most important factors influencing the activity of a good photocatalyst. Herein, we developed a 1D/2D heterojunction in the composite of CdS nanorod and g-C3N4 (CN) nanosheets. These two form a quasi-type-II junction at the heterointerface. The photoexcited electrons are supposed to be transferred from CN to CdS, as observed from the enhanced photoluminescence of CdS. Transient studies revealed an absolute dominance of CdS exciton formation even in the composite system, although the dynamics were substantially modified in the presence of CN. The rise time of CdS band edge excitons were increased in the composite material, owing to the migration of hot electrons from CN to CdS. The hot electron transfer time was found to be ∼0.5 ps (rate constant ∼1.98 ps-1). The excitons decay in a much slower manner than that of the pristine CdS, confirming enhanced electron population in CdS. This migration of charge carriers was found to be immensely dependent on the applied excitation photon energy. Efficient migration of charge carriers leads to enhanced photocatalytic activity in the composite and an increased evolution of H2 evolution rate was witnessed. This detailed spectroscopic study toward the mechanistic pathway of the catalytic activity of an 1D/2D heterocomposite would be immensely helpful in fabricating many other effective heterojunctions which will advance the catalysis research.
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Affiliation(s)
- Tanmay Goswami
- Institute of Nano Science and Technology, Knowledge City, Sector 81, SAS Nagar, Punjab 140306, India
| | - Himanshu Bhatt
- Institute of Nano Science and Technology, Knowledge City, Sector 81, SAS Nagar, Punjab 140306, India
| | - Dharmendra Kumar Yadav
- Institute of Nano Science and Technology, Knowledge City, Sector 81, SAS Nagar, Punjab 140306, India
| | - Hirendra N Ghosh
- Institute of Nano Science and Technology, Knowledge City, Sector 81, SAS Nagar, Punjab 140306, India.,Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India
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19
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Preeyanghaa M, Vinesh V, Neppolian B. Complete removal of Tetracycline by sonophotocatalysis using ultrasound-assisted hierarchical graphitic carbon nitride nanorods with carbon vacancies. CHEMOSPHERE 2022; 287:132379. [PMID: 34597637 DOI: 10.1016/j.chemosphere.2021.132379] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 09/16/2021] [Accepted: 09/25/2021] [Indexed: 06/13/2023]
Abstract
Tuning a graphitic carbon nitride (CN) structure is an effective strategy to advance its physicochemical and electronic properties. Herein, hierarchical CN nanorods with carbon vacancy were synthesized via ultrasound-assisted thermal polycondensation method wherein melamine-HONH2·HCl complex acts as a template. The hierarchical CN nanorods can facilitate multiple light scattering, provide large specific surface area with extensive reactive sites and endow abundant mass-transport channels for charge migration. The existence of carbon vacancies can serve as shallow charge trapping sites and prompt charge separation. Consequently, hierarchical CN nanorod possessed excellent sonophotodegradation efficiency of ∼100% towards Tetracycline (TC) antibiotic within 60 min under ultrasonic irradiation and visible light illumination. Moreover, the sonophotocatalytic degradation was higher than the sum of sonocatalytic and photocatalytic TC degradation using hierarchical CN nanorods due to its synergistic performance. A plausible sonophotocatalytic mechanism and TC degradation pathway using hierarchical CN nanorod were proposed. Lastly, hierarchical CN nanorod is durable and stable which can withstand the sonophotocatalytic condition even after the fifth run. This work offers an insight into hierarchical CN nanorod to advance sonophotocatalytic degradation performance for highly efficient removal of various recalcitrant pollutants.
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Affiliation(s)
- Mani Preeyanghaa
- Departments of Physics and Nanotechnology, SRM Research Institute, SRM Institute of Science and Technology, Kattankulathur, Chennai, 603203, India
| | - Vasudevan Vinesh
- Departments of Physics and Nanotechnology, SRM Research Institute, SRM Institute of Science and Technology, Kattankulathur, Chennai, 603203, India
| | - Bernaurdshaw Neppolian
- Departments of Physics and Nanotechnology, SRM Research Institute, SRM Institute of Science and Technology, Kattankulathur, Chennai, 603203, India.
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20
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Ghosh HNATH, Goswami T, Bhatt H, Yadav DK. Atomically Thin 2D Photocatalysts for Boosted H2 Production from the perspective of Transient Absorption Spectroscopy. Phys Chem Chem Phys 2022; 24:19121-19143. [DOI: 10.1039/d2cp02148j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Excited state photophysical processes play the most important role in deciding the efficiency of any photonic applications like solar light driven H2 evolution, which is considered to be the next...
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21
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Bhatt H, Goswami T, Yadav DK, Ghorai N, Shukla A, Kaur G, Kaur A, Ghosh HN. Ultrafast Hot Electron Transfer and Trap-State Mediated Charge Carrier Separation toward Enhanced Photocatalytic Activity in g-C 3N 4/ZnIn 2S 4 Heterostructure. J Phys Chem Lett 2021; 12:11865-11872. [PMID: 34874742 DOI: 10.1021/acs.jpclett.1c03356] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Comprehensive understanding of charge carrier dynamics in the heterostructure based photocatalytic materials will strengthen their candidature as future solar energy harvesting resources. Here, in this work, the g-C3N4(CN)/ZnIn2S4 (ZIS) heterostructure was successfully synthesized and a direct spectroscopic correlation was established between excited-state charge carrier dynamics and enhanced photocatalytic activity using ultrafast transient absorption (TA) spectroscopy. TA analysis demonstrated the dominance of hot electron transfer over the band edge one. The photogenerated hot electrons migrated from the high-energy excitonic states of CN toward ZIS in the subpicosecond time scale. Broad-band (UV to NIR) ultrafast transient pump-probe spectroscopy revealed the collective effect of hot electron transfer as well as trap-state mediated electron delocalization in the enhanced photocatalytic H2 evolution. This work reveals the role of photogenerated carriers in the photocatalytic performance of the CN/ZIS heterostructure and would create a new avenue toward the advancement of CN based heterostructure in photocatalytic devices.
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Affiliation(s)
- Himanshu Bhatt
- Institute of Nano Science and Technology, Knowledge City, Sector 81, SAS Nagar, Punjab 140306, India
| | - Tanmay Goswami
- Institute of Nano Science and Technology, Knowledge City, Sector 81, SAS Nagar, Punjab 140306, India
| | - Dharmendra Kumar Yadav
- Institute of Nano Science and Technology, Knowledge City, Sector 81, SAS Nagar, Punjab 140306, India
| | - Nandan Ghorai
- Institute of Nano Science and Technology, Knowledge City, Sector 81, SAS Nagar, Punjab 140306, India
| | - Ayushi Shukla
- Institute of Nano Science and Technology, Knowledge City, Sector 81, SAS Nagar, Punjab 140306, India
| | - Gurpreet Kaur
- Institute of Nano Science and Technology, Knowledge City, Sector 81, SAS Nagar, Punjab 140306, India
| | - Arshdeep Kaur
- Institute of Nano Science and Technology, Knowledge City, Sector 81, SAS Nagar, Punjab 140306, India
| | - Hirendra N Ghosh
- Institute of Nano Science and Technology, Knowledge City, Sector 81, SAS Nagar, Punjab 140306, India
- Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085, India
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22
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Chae SY, Kim Y, Park ED, Im SH, Joo OS. CuInS 2 Photocathodes with Atomic Gradation-Controlled (Ta,Mo) x(O,S) y Passivation Layers for Efficient Photoelectrochemical H 2 Production. ACS APPLIED MATERIALS & INTERFACES 2021; 13:58447-58457. [PMID: 34450006 DOI: 10.1021/acsami.1c09560] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
An atomic gradient passivation layer, (Ta,Mo)x(O,S)y, is designed to improve the charge transportation and photoelectrochemical activity of CuInS2-based photoelectrodes. We found that Mo spontaneously diffused to the a-TaOx layer during e-beam evaporation. This result indicates that the gradient profile of MoOx/TaOx is formed in the sublayer of (Ta,Mo)x(O,S)y. To understand the atomic-gradation effects of the (Ta,Mo)x(O,S)y passive layer, the composition and (photo)electrochemical properties have been characterized in detail. When this atomic gradient-passive layer is applied to CuInS2-based photocathodes, promising photocurrent and onset potential are seen without using Pt cocatalysts. This is one of the highest activities among reported CuInS2 photocathodes, which are not combined with noble metal cocatalysts. Excellent photoelectrochemical activity of the photoelectrode can be mainly achieved by (1) the electron transient time improved due to the conductive Mo-incorporated TaOx layer and (2) the boosted electrocatalytic activity by Mox(O,S)y formation.
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Affiliation(s)
- Sang Youn Chae
- Institute of NT-IT Fusion Technology, Ajou University, Suwon 16499, Republic of Korea
| | - Yoolim Kim
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
- Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Eun Duck Park
- Department of Chemical Engineering and Department of Energy Systems Research, Ajou University, Suwon 16499, Republic of Korea
| | - Sang Hyuk Im
- Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Oh-Shim Joo
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
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23
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Mitchell E, Law A, Godin R. Interfacial charge transfer in carbon nitride heterojunctions monitored by optical methods. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C: PHOTOCHEMISTRY REVIEWS 2021. [DOI: 10.1016/j.jphotochemrev.2021.100453] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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24
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Liang H, Yu M, Guo J, Zhan R, Chen J, Li D, Zhang L, Niu J. A novel vacancy-strengthened Z-scheme g-C3N4/Bp/MoS2 composite for super-efficient visible-light photocatalytic degradation of ciprofloxacin. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2021.118891] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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25
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Liang H, Guo J, Yu M, Zhou Y, Zhan R, Liu C, Niu J. Porous loofah-sponge-like ternary heterojunction g-C 3N 4/Bi 2WO 6/MoS 2 for highly efficient photocatalytic degradation of sulfamethoxazole under visible-light irradiation. CHEMOSPHERE 2021; 279:130552. [PMID: 33901890 DOI: 10.1016/j.chemosphere.2021.130552] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/08/2021] [Accepted: 04/09/2021] [Indexed: 06/12/2023]
Abstract
A novel porous loofah-sponge-like ternary heterojunction g-C3N4/Bi2WO6/MoS2 (CN-BM) was prepared via a facile method. The introduction of binary Bi2WO6/MoS2 into g-C3N4 could be qualified for constructing reasonable heterostructure while regulating photocatalysts morphology. Benefiting from the unique structure, the ternary heterojunction composites not only inhibited the agglomeration but also exhibited the prominent visible-light harvest capacity and abundant active sites, which could accelerate the photogenerated carriers separation and preserve the robust redox ability. The results showed that the optimized sample (CN-BM2) displayed the excellent degradation efficiency of sulfamethoxazole (SMX) under visible-light irradiation (over 99% within 60 min), and the fitted pseudo-first-order kinetic rate constant reached to 0.089 min-1, where it was 3.17 times than that of pure CN. Additionally, the radical scavenger experiments and electron spin resonance experiments indicated that the active species super-oxide radical and hole played a major role in the degradation experiment. The charge transfer mechanism was proposed and the main intermediates indicated that the active radicals attacked on the benzene ring and isoxazole ring in SMX, and further mineralized to inorganic molecules eventually.
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Affiliation(s)
- Huanjing Liang
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China
| | - Jiaying Guo
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China
| | - Mingchuan Yu
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China.
| | - Yufei Zhou
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China
| | - Ruonan Zhan
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China
| | - Cong Liu
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China
| | - Junfeng Niu
- Research Center for Eco-environmental Engineering, Dongguan University of Technology, Dongguan, 523808, China.
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26
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Tsao CW, Fang MJ, Hsu YJ. Modulation of interfacial charge dynamics of semiconductor heterostructures for advanced photocatalytic applications. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2021.213876] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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27
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Xue J, Fujitsuka M, Majima T. Defect-mediated electron transfer in photocatalysts. Chem Commun (Camb) 2021; 57:3532-3542. [PMID: 33729263 DOI: 10.1039/d1cc00204j] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Photocatalysis holds great potential in alleviating the growing energy crisis and environmental issues. Defect engineering has been demonstrated as an effective method to modulate the electronic structure of semiconductor photocatalysts for enhanced visible light absorption. However, the effect of defects on photocatalytic activity is still under debate because of the elusive charge transfer process mediated by defects. In this feature article, we summarize our recent progress in unraveling the defect-mediated electron transfer of the widely studied TiO2 and polymeric carbon nitride photocatalysts by combining ultrafast time-resolved spectroscopy and theoretical simulations. We find that the photogenerated electron transfer is greatly dependent on the type and concentration of defects. The location and occupation of defect states, and the dispersion degree of the energy band should be carefully tuned to maximize the advantages of defects for photocatalytic reactions.
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Affiliation(s)
- Jiawei Xue
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, P. R. China
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28
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Iqbal A, Kafizas A, Sotelo-Vazquez C, Wilson R, Ling M, Taylor A, Blackman C, Bevan K, Parkin I, Quesada-Cabrera R. Charge Transport Phenomena in Heterojunction Photocatalysts: The WO 3/TiO 2 System as an Archetypical Model. ACS APPLIED MATERIALS & INTERFACES 2021; 13:9781-9793. [PMID: 33595275 DOI: 10.1021/acsami.0c19692] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Recent studies have demonstrated the high efficiency through which nanostructured core-shell WO3/TiO2 (WT) heterojunctions can photocatalytically degrade model organic pollutants (stearic acid, QE ≈ 18% @ λ = 365 nm), and as such, has varied potential environmental and antimicrobial applications. The key motivation herein is to connect theoretical calculations of charge transport phenomena, with experimental measures of charge carrier behavior using transient absorption spectroscopy (TAS), to develop a fundamental understanding of how such WT heterojunctions achieve high photocatalytic efficiency (in comparison to standalone WO3 and TiO2 photocatalysts). This work reveals an order of magnitude enhancement in electron and hole recombination lifetimes, respectively located in the TiO2 and WO3 sides, when an optimally designed WT heterojunction photocatalyst operates under UV excitation. This observation is further supported by our computationally captured details of conduction band and valence band processes, identified as (i) dominant electron transfer from WO3 to TiO2 via the diffusion of excess electrons; and (ii) dominant hole transfer from TiO2 to WO3 via thermionic emission over the valence band edge. Simultaneously, our combined theoretical and experimental study offers a time-resolved understanding of what occurs on the micro- to milliseconds (μs-ms) time scale in this archetypical photocatalytic heterojunction. At the microsecond time scale, a portion of the accumulated holes in WO3 contribute to the depopulation of W5+ polaronic states, whereas the remaining accumulated holes in WO3 are separated from adjacent electrons in TiO2 up to 3 ms after photoexcitation. The presence of these exceptionally long-lived photogenerated carriers, dynamically separated by the WT heterojunction, is the origin of the superior photocatalytic efficiency displayed by this system (in the degradation of stearic acid). Consequently, our combined computational and experimental approach delivers a robust understanding of the direction of charge separation along with critical time-resolved insights into the evolution of charge transport phenomena in this model heterojunction photocatalyst.
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Affiliation(s)
- Asif Iqbal
- Materials Engineering, McGill University, 3610 University Street, Montréal Quebec H3A 0C5, Canada
| | - Andreas Kafizas
- Department of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom
- The Grantham Institute, Imperial College London, London SW7 2AZ, United Kingdom
| | - Carlos Sotelo-Vazquez
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Rachel Wilson
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Min Ling
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Alaric Taylor
- Department of Electronic & Electrical Engineering, University College London, Torrington Place, London WC1E 7JE, United Kingdom
| | - Chris Blackman
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Kirk Bevan
- Materials Engineering, McGill University, 3610 University Street, Montréal Quebec H3A 0C5, Canada
| | - Ivan Parkin
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
| | - Raul Quesada-Cabrera
- Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom
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29
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Mitchell E, Law A, Godin R. Experimental determination of charge carrier dynamics in carbon nitride heterojunctions. Chem Commun (Camb) 2021; 57:1550-1567. [PMID: 33491708 DOI: 10.1039/d0cc06841a] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Carbon nitride (CNx) is an emerging photocatalyst with the potential to efficiently produce solar fuels. CNx heterojunctions often show significant photocatalytic activity improvements. We review the charge carrier dynamics in a range of CNx heterojunctions including carbon-based material, black phosphorus, Ru complexes, molybdenum sulphide and metal phosphides. Time resolved photoluminescence (TRPL) and transient absorption spectroscopy (TAS) were the most common techniques employed for experimental charge carrier dynamics measurements. The low photoluminescence quantum yield of CNx appeared to limit the depth of conclusions from TRPL, with both lengthening and shortening of the TRPL lifetimes observed and attributed to enhanced charge separation. Overall, the charge carrier dynamics studies often showed a relative lifetime change of ∼2-fold and an activity improvement of >10-fold. We highlight the need for the use of a wider range of techniques to monitor the charge carrier dynamics for conclusive determination of photophysics-activity relationships and elucidation of improvement mechanisms.
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Affiliation(s)
- Emma Mitchell
- Department of Chemistry, The University of British Columbia, 3247 University Way, Kelowna, BC, V1V 1V7, Canada
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30
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Intrinsic carbon-doping induced synthesis of oxygen vacancies-mediated TiO2 nanocrystals: Enhanced photocatalytic NO removal performance and mechanism. J Catal 2021. [DOI: 10.1016/j.jcat.2020.11.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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31
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Wang M, Tan G, Dang M, Wang Y, Zhang B, Ren H, Lv L, Xia A. Dual defects and build-in electric field mediated direct Z-scheme W18O49/g-C3N4−x heterojunction for photocatalytic NO removal and organic pollutant degradation. J Colloid Interface Sci 2021; 582:212-226. [DOI: 10.1016/j.jcis.2020.08.040] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 07/31/2020] [Accepted: 08/11/2020] [Indexed: 12/12/2022]
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32
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Han C, Du L, Konarova M, Qi DC, Phillips DL, Xu J. Beyond Hydrogen Evolution: Solar-Driven, Water-Donating Transfer Hydrogenation over Platinum/Carbon Nitride. ACS Catal 2020. [DOI: 10.1021/acscatal.0c01932] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Chenhui Han
- School of Chemistry and Physics, Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Lili Du
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, China
- Institute of Life Sciences, Jiangsu University, Zhenjiang 212013, China
| | - Muxina Konarova
- Australian Institute of Bioengineering and Nanotechnology (AIBN), University of Queensland, Brisbane, QLD 4072, Australia
| | - Dong-Chen Qi
- School of Chemistry and Physics, Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD 4000, Australia
- Centre for Materials Science, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - David Lee Phillips
- Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, China
| | - Jingsan Xu
- School of Chemistry and Physics, Science and Engineering Faculty, Queensland University of Technology, Brisbane, QLD 4000, Australia
- Centre for Materials Science, Queensland University of Technology, Brisbane, QLD 4000, Australia
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33
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Xue J, Fujitsuka M, Majima T. Shallow trap state-enhanced photocatalytic hydrogen evolution over thermal-decomposed polymeric carbon nitride. Chem Commun (Camb) 2020; 56:5921-5924. [PMID: 32342976 DOI: 10.1039/d0cc01870h] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We investigate the photogenerated electron kinetics of a thermal-decomposed polymeric carbon nitride (TCN) synthesized in air using femtosecond time-resolved diffuse reflectance spectroscopy. We find that the oxygen functional groups in TCN contribute to the formation of reactive shallow trap states for photogenerated electrons, leading to an enhanced activity for photocatalytic hydrogen evolution.
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Affiliation(s)
- Jiawei Xue
- The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan.
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34
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Xue J, Fujitsuka M, Majima T. Near Bandgap Excitation Inhibits the Interfacial Electron Transfer of Semiconductor/Cocatalyst. ACS APPLIED MATERIALS & INTERFACES 2020; 12:5920-5924. [PMID: 31913002 DOI: 10.1021/acsami.9b20247] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Understanding the ultrafast interfacial electron transfer (IET) process is essential for establishing the structure-property relationship of the semiconductor/cocatalyst system for photocatalytic H2 evolution. However, the IET kinetics for the near bandgap excitation has not been reported. Herein, we investigate the IET kinetics of g-C3N4/Pt as a semiconductor/cocatalyst prototype by femtosecond time-resolved diffuse reflectance spectroscopy. We find that the near bandgap excitation of g-C3N4 inhibits the IET of g-C3N4/Pt due to electron deep trapping, resulting in a markedly decreased apparent quantum efficiency for photocatalytic H2 evolution. This work complements the kinetic understanding for the photocatalytic mechanism of the semiconductor/cocatalyst system in its whole light absorption range.
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Affiliation(s)
- Jiawei Xue
- The Institute of Scientific and Industrial Research (SANKEN) , Osaka University , Mihogaoka 8-1 , Osaka , Ibaraki 567-0047 , Japan
| | - Mamoru Fujitsuka
- The Institute of Scientific and Industrial Research (SANKEN) , Osaka University , Mihogaoka 8-1 , Osaka , Ibaraki 567-0047 , Japan
| | - Tetsuro Majima
- The Institute of Scientific and Industrial Research (SANKEN) , Osaka University , Mihogaoka 8-1 , Osaka , Ibaraki 567-0047 , Japan
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