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Xu F, An N, Lai C, Zhang M, Li B, Liu S, Li L, Qin L, Fu Y, Yi H, Yan H. Nitrogen-doping coupled with cerium oxide loading co-modified graphitic carbon nitride for highly enhanced photocatalytic degradation of tetracycline under visible light. CHEMOSPHERE 2022; 293:133648. [PMID: 35063563 DOI: 10.1016/j.chemosphere.2022.133648] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 12/11/2021] [Accepted: 01/14/2022] [Indexed: 06/14/2023]
Abstract
The increasingly serious pollution of antibiotics brings an enormous threat to the ecological environment and human health. Graphite phase carbon nitride (g-C3N4), as a popular photocatalytic material, is widely used in photocatalytic degradation of antibiotics in water. In order to make up for the shortage of g-C3N4 monomer, CeO2/N-doped g-C3N4 (CeNCN) composite photocatalysts co-modified with nitrogen doping and CeO2 loading were designed and synthesized with the idea of expanding visible light absorption and promoting photogenerated carrier separation. CeNCN exhibits excellent photodegradation performance, the removal rate of tetracycline reached 80.09% within 60 min, which is much higher than that of g-C3N4 (CN) and N-doped g-C3N4 (NCN); and the quasi-first-order degradation rate constant is 0.0291, which is 7.86 and 2.29 times higher than CN and NCN. Electron spin resonance and free radical trapping experiments confirmed that h+, O2- and OH are the active substances in the photocatalytic system. After 5 cycles, the degradation efficiency of tetracycline still exceeds 75%, which indicates that CeNCN has good stability. This work proves that N-doping and CeO2 loading can effectively broaden the photoresponse range of g-C3N4, facilitate the separation of photogenerated electron-hole pairs, and provide a reference for the construction of g-C3N4-based photocatalyst with high-efficiency photodegradation activity.
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Yeganeh M, Sobhi HR, Esrafili A. Efficient photocatalytic degradation of metronidazole from aqueous solutions using Co/g-C 3N 4/Fe 3O 4 nanocomposite under visible light irradiation. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:25486-25495. [PMID: 34843049 DOI: 10.1007/s11356-021-17077-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 10/12/2021] [Indexed: 06/13/2023]
Abstract
Herein, the efficient degradation of a highly consumed antibiotic known as metronidazole (MNZ) in aqueous solutions using Co/g-C3N4/Fe3O4 nanocomposite under visible light irradiation was accomplished. Initially, the photocatalyst (Co/g-C3N4/Fe3O4) was synthesized by a simple hydrothermal method and then characterized by several analytical techniques, namely EDS, SEM, XRD, UV-vis DRS, and FTIR. The efficiency of the synthesized photocatalyst with regard to the degradation of the studied antibiotic (MNZ) under visible light irradiation was fully evaluated. The influential operational parameters affecting the efficiency of the degradation process such as pH (2-10), nanocomposite dosage (0.2-1 g/L), MNZ concentration (5-20 mg/L), and irradiation time (0-80 min) were optimized. The results revealed that the maximum degradation efficiency for MNZ was obtained under the following conditions: irradiation time of 60 min, pH = 8, MNZ concentration of 5 mg/L, and photocatalyst dosage of 0.7 g/L. In addition, the degradation of MNZ followed the pseudo-first-order kinetic model. The best rate constant (k) value was determined to be 0.0102 min-1 with the correlation coefficient (R2) of 0.992. According to the results of the quenching tests, it was found out that hydroxyl radicals (OH°) were the main species responsible for the MNZ degradation. Furthermore, the applied photocatalyst (Co/g-C3N4/Fe3O4) exhibited a high level of recovery and stability after five cycles of reuse. Co/g-C3N4/Fe3O4/Vis system exhibited an excellent performance in the treatment of wastewater and real water samples. Finally, it was concluded that the synthesized nanocomposite could be potentially used as a promising and suitable photocatalyst in the degradation of other antibiotics.
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153
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Wang C, Wu G, Zhu X, Xing Y, Yuan X, Qu J. Synergistic degradation for o-chlorophenol and enhancement of power generation by a coupled photocatalytic-microbial fuel cell system. CHEMOSPHERE 2022; 293:133517. [PMID: 34995621 DOI: 10.1016/j.chemosphere.2022.133517] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 12/24/2021] [Accepted: 12/31/2021] [Indexed: 06/14/2023]
Abstract
A hierarchically photocatalytic microbial fuel cell system (PMFC) coupled with TiO2 photoanode and bioanode was established to enhance the power generation based on single-chamber MFC. Compared with the conventional anaerobic mode, oxygen in the solution could be utilized by the photoanode of PMFC to improve the removal of o-chlorophenol (2-CP). The maximum power densities were increasing from 261 (MFC) to 301 mW/m2 (PMFC). The removal efficiency of 2-CP (5 mg/L) in PMFC was 76.20% and higher than that in MFC (19.33%) and by photocatalysis (49.23%). The electron-hole separation efficiencies were decreasing with the increasing of dissolved oxygen, causing a low efficiency of photocatalysis, due to the reduction of the current density of the systems. The abundance of Geobacter sp., PHOS-HE36 fam., and Pseudomonas sp. was increased with illumination, contributing to improve the electricity production and 2-CP degradation. The only detective intermediate of 1,2-dichlorobenzene in PMFC indicated that the microbes could regulate the degradation pathway of 2-CP in the coupling system. These findings provided an feasible method for the effective degradation of refractory organic compounds and simultaneous energy recovery by combining photocatalysis and microbial power generation.
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AlAbdulaal T, AlShadidi M, Hussien M, Ganesh V, Bouzidi AF, Rafique S, Algarni H, Zahran H, Abdel-Wahab M, Yahia I. Multifunctional and smart Er 2O 3-ZnO nanocomposites for electronic ceramic varistors and visible light degradation of wastewater treatment. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:19109-19131. [PMID: 34713401 DOI: 10.1007/s11356-021-16754-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 09/22/2021] [Indexed: 06/13/2023]
Abstract
In this proposed study, erbium (Er3+)-doped ZnO nanocomposites were prepared through the effective, basic, and green combustion method. The significant effects of Er dopants on the structural, morphological features, dielectric, and optical behaviors of the pure ZnO matrix as well as Er2O3-ZnO nanostructured materials were investigated applying X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transformation infrared (FT-IR) spectroscopy, and UV-Vis spectrophotometer techniques. These results showed that the synthesized Er2O3-ZnO nanocomposites are well polycrystalline. The Er2O3-ZnO nanocomposites are almost uniformly distributed on the surface morphologies. Furthermore, UV-Vis diffuse reflectance spectroscopy, AC electrical conductivity, and dielectric properties' current-voltage characteristics were utilized to examine the influence of erbium doping on the optical properties, energy bandgaps of the proposed Er2O3-ZnO nanostructured powder. The tested nano-samples were applied for the visible light photodegradation of p-chlorophenol(4-CP) and p-nitrophenol (4-NP). The Er-doped ZnO ratio affects the photocatalytic activity of the ZnO matrix. This current research substantiated that more than 99.5% of 4-CP and 4-NP were photodegraded through 30 min of irradiation. Four times, the Er:ZnO nanocatalysts were used and still displayed an efficiency of more than 96.5% for 4-CP and 4-NP degradations in the specified period of 30 min. The as-prepared Er2O3-ZnO nanostructures are considered novel potential candidates in broad nano-applications from visible photocatalytic degradation of waste pollutants to the electronic varistor devices.
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155
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Chen ML, Lu TH, Li SS, Wen L, Xu Z, Cheng YH. Photocatalytic degradation of imidacloprid by optimized Bi 2WO 6/NH 2-MIL-88B(Fe) composite under visible light. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:19583-19593. [PMID: 34719759 DOI: 10.1007/s11356-021-17187-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 10/20/2021] [Indexed: 05/19/2023]
Abstract
Imidacloprid as a widely used neonicotinoid insecticide can cause harmful pesticide residue inevitably. Metal-organic frameworks (MOFs) were innovatively composited to improve the light absorption and degradation performance of Bi2WO6 semiconductor, which expanded the photodegradation application in solving environmental problems. Based on the synergistic effect of Bi2WO6 and NH2-MIL-88B(Fe), a Bi2WO6/NH2-MIL-88B(Fe) (BNM) heterojunction photocatalyst with high-performance of photocatalytic degradation activities was successfully synthesized. The optimized BNM catalyst had a good degradation rate under visible light, which was mainly caused by generation of the active ·OH. Transient photocurrent response and electrochemical impedance tests verified that 1:2 BNM exhibits a highest charge separation and a lowest carrier recombination rate which were favorable to the photocatalytic activity. Cycle experiments show that the composite photocatalyst had good reusability and stability which were very important for potential industry applications.
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156
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Li Z, Li D, Xue R, Zang L, Ma H, Guo S, Shi L. Ni-MOL/In 2Se 3 heterostructure construction with mixed metal (Ti/Ni) for efficient photocatalytic tetracycline degradation. CHEMOSPHERE 2022; 291:132743. [PMID: 34743801 DOI: 10.1016/j.chemosphere.2021.132743] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/27/2021] [Accepted: 10/28/2021] [Indexed: 06/13/2023]
Abstract
To investigate the mechanism of bimetallic 2-dimension (2D) catalyst existing in the current photocatalytic degradation process, the tetracycline (TC) degradation performance and mechanism by bimetallic 2D photocatalyst was studied extensively. Nickel metal-organic layer (Ni-MOL) and In2Se3, a typical 2D semiconductor photocatalyst, shows great potential for photocatalytic degradation of TC. Herein, an In2Se3 assisted Ni-MOL composite bimetallic photocatalyst was assembled, of which could obtain the degradation rate of 96.4% within 90 min for TC under visible light. Ni-MOL was the main active site for TC degradation by photo-induced holes which located at the Ni atom active site during the photocatalytic process. The role of In2Se3 and the element of Ti in Ni-MOL was to assist Ni-MOL by providing more photo-induced carriers and inhibiting carrier recombination. This work makes a contribution to the application of 2D bimetallic photocatalytic in TC degradation.
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157
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Zhang H, Zhang Y, Zhong Y, Ding J. Novel strategies for 2,8-dichlorodibenzo-p-dioxin degradation using ternary Au-modified iron doped TiO 2 catalysts under UV-vis light illumination. CHEMOSPHERE 2022; 291:132826. [PMID: 34774912 DOI: 10.1016/j.chemosphere.2021.132826] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 10/25/2021] [Accepted: 11/05/2021] [Indexed: 06/13/2023]
Abstract
Polychlorinated dibenzo-p-dioxins (PCDDs), characterized by their extreme toxicity, high persistency and bioaccumulation, regard as one of the most concerned environmental pollutants on the priority list. In this study, microwave-hydrothermal and photoreduction methods were adopted for fabrication of ternary Au@Fe/TiO2 composites for removal of 2,8-dichlorodibenzo-p-dioxin (2,8-DCDD) under UV-Vis light irradiation. The acquired materials were characterized and analyzed by XRD, TEM, XPS, UV-Vis DRS, PL, etc. As a result, the 1%Au@1%Fe/TiO2 exhibited much higher photocatalytic activity that 96.3% of 2,8-DCDD was removed within 160 min with respect to that of Fe/TiO2 (3.0 times) and TiO2 (5.5 times). It revealed the active substances might be produced, which were verified by ESR analysis. In a comparison, the 1%Au@1%Fe/TiO2 also exhibited high activity in that 97.2% of 2,8-DCDD was removed within 240 min under an anoxic atmosphere. The 1%Au@1%Fe/TiO2 systems were all pH-dependent that 2,8-DCDD could be fully degraded in neutral conditions. The results of repeatability on 1%Au@1%Fe/TiO2 showed that the sample was high stability. Fe doping improved the charge separation of TiO2 and Au modification improved the activity via SPR effect and Mott-Schottky barrier. The degradation mechanisms and pathways were proposed and discussed in detail. The current work develops a new approach on photocatalytic oxidation and reductive dechlorination of dioxins and may open a new opportunity to extend the application range of TiO2 catalysts.
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158
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Zhang T, Huang H, Zhang W, Lu Z, Shen M, Liu T, Bai J, Yang Y, Zhang J. Free-standing hybrid film for separation of dye pollutant with self-cleaning ability under visible light. CHEMOSPHERE 2022; 291:132725. [PMID: 34718025 DOI: 10.1016/j.chemosphere.2021.132725] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 10/24/2021] [Accepted: 10/26/2021] [Indexed: 06/13/2023]
Abstract
The development of low cost and environmental-friendly materials has long been an ambition for effective removal of dye pollutants in complex water environments. In this study, a free-standing separation film of bacterial cellulose reinforced/functionalized by graphitic phase carbon nitride is developed by a facile suction filtration strategy, of which the former is precoated by polypyrrole, and the latter is pre-doped by oxygen to endow the as-obtained film an enhanced photocatalytic performance and self-cleaning ability. The as-obtained film exhibits a high tensile stress of 51.8 ± 1.1 MPa, and a high resistance to cold, heat, acid and alkali. For typical dyes of methylene blue and rhodamine B, a high dye rejection rate of 99.9% at 138 L/m2•h•bar feed flux is obtained by the as-obtained film. Even at a salt concentration higher than 5%, it still maintained high dye removal rates and achieves effective separation of dye and salt. Simultaneously, a high dye photocatalytic degradation of the composite films rates up to 98% in only 90 min, and a high self-cleaning ability demonstrated by recovery of flux after light treatment in cyclic tests. The density functional theory calculation validates the beneficial effects of improved light response range and separated photogenerated electron/holes for the effective degradation of dyes by oxygen-doped carbon nitride coupled with one-dimensional polypyrrole chains. Overall, this study proposes a new direction for the separation of dye pollutants with a high visible-light self-cleaning capacity by structural tailoring of bacterial cellulose with carbon nitride.
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159
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Wu Y, Ji H, Liu Q, Sun Z, Li P, Ding P, Guo M, Yi X, Xu W, Wang CC, Gao S, Wang Q, Liu W, Chen S. Visible light photocatalytic degradation of sulfanilamide enhanced by Mo doping of BiOBr nanoflowers. JOURNAL OF HAZARDOUS MATERIALS 2022; 424:127563. [PMID: 34736201 DOI: 10.1016/j.jhazmat.2021.127563] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 10/11/2021] [Accepted: 10/18/2021] [Indexed: 06/13/2023]
Abstract
Design of high-efficiency visible light photocatalysts is critical in the degradation of antibiotic pollutants in water, a key step towards environmental remediation. In the present study, Mo-doped BiOBr nanocomposites are prepared hydrothermally at different feed ratios, and display remarkable visible light photocatalytic activity towards the degradation of sulfanilamide, a common antibacterial drug. Among the series, the sample with 2% Mo dopants exhibits the best photocatalytic activity, with a performance 2.3 times better that of undoped BiOBr. This is attributed to Mo doping that narrows the band gap of BiOBr and enhances absorption in the visible region. Additional contributions arise from the unique materials morphology, where the highly exposed (102) crystal planes enrich the photocatalytic active sites, and facilitate the adsorption of sulfanilamide molecules and their eventual attack by free radicals. The reaction mechanism and pathways are then unraveled based on theoretical calculations of the Fukui index and liquid chromatography/mass spectrometry measurements of the reaction intermediates and products. Results from this study indicate that deliberate structural engineering based on heteroatom doping and morphological control may serve as an effective strategy in the design of highly active photocatalysts towards antibiotic degradation.
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160
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Sanito RC, You SJ, Wang YF. Degradation of contaminants in plasma technology: An overview. JOURNAL OF HAZARDOUS MATERIALS 2022; 424:127390. [PMID: 34879580 PMCID: PMC8500698 DOI: 10.1016/j.jhazmat.2021.127390] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 09/27/2021] [Accepted: 09/28/2021] [Indexed: 05/19/2023]
Abstract
The information of plasma technologies applications for environmental clean-up on treating and degrading metals, metalloids, dyes, biomass, antibiotics, pesticides, volatile organic compounds (VOCs), bacteria, virus and fungi is compiled and organized in the review article. Different reactor configurations of plasma technology have been applied for reactive species generation, responsible for the pollutants removal, hydrogen and methane production and microorganism inactivation. Therefore, in this review article, the reactive species from discharge plasma are presented here to provide the insight into the environmental applications. The combinations of plasma technology with flux agent and photocatalytic are also given in this review paper associated with the setup of the plasma system on the removal process of metals, VOCs, and microorganisms. Furthermore, the potential of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) inactivation via plasma technology is also described in this review paper. Detailed information of plasma parameter configuration is given to support the influence of the critical process in the plasma system to deal with contaminants.
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161
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In situ grown bacterial cellulose/MoS 2 composites for multi-contaminant wastewater treatment and bacteria inactivation. Carbohydr Polym 2022; 277:118853. [PMID: 34893262 DOI: 10.1016/j.carbpol.2021.118853] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/08/2021] [Accepted: 11/02/2021] [Indexed: 01/06/2023]
Abstract
For the purpose of developing multifunctional water purification materials capable of degrading organic pollutants while simultaneously inactivating microorganisms from contaminated wastewater streams, we report here a facile and eco-friendly method to immobilize molybdenum disulfide into bacterial cellulose via a one-step in-situ biosynthetic method. The resultant nanocomposite, termed BC/MoS2, was shown to possess a photocatalytic activity capable of generating •OH from H2O2, while also exhibiting photodynamic/photothermal mechanisms, the combination of which exhibits synergistic activity for the degradation of pollutants as well as for bacterial inactivation. In the presence of H2O2, the BC/MoS2 nanocomposite exhibited excellent antibacterial efficacy upwards of 99.9999% (6 log units) for the photoinactivation of both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus upon infrared (IR) lamp illumination (100 W, 760 nm ≤ λ ≤ 5000 nm, 15 cm vertical distance; 5 min). Mechanistic studies revealed synergistic pathogen inactivation resulting from the combination of photocatalytically generated •OH and hyperthermia induced by the photothermal conversion of the near-IR light. In addition, the BC/MoS2 nanocomposite also showed excellent photodegradation activity for common aqueous contaminants in the presence of H2O2, including malachite green (a textile dye), catechol violet (a phenol) and formaldehyde. Taken together, our findings demonstrate that sustainable materials such as BC/MoS2 have potential applications in wastewater treatment and microorganism disinfection.
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162
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Xu K, Jiao L, Wang C, Bu Y, Tang Y, Qiu L, Zhang Q, Wang L. Nonylphenol photodegradation by novel ternary MIL-100(Fe)/ZnFe 2O 4/PCN composite under visible light irradiation via double charge transfer process. J Environ Sci (China) 2022; 111:93-103. [PMID: 34949377 DOI: 10.1016/j.jes.2021.03.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 03/10/2021] [Accepted: 03/11/2021] [Indexed: 06/14/2023]
Abstract
Nonylphenol (NP) residues, as a typical endocrine disrupting chemical (EDC), frequently exist in sewage, surface water, groundwater and even drinking water, which poses a serious threat to human health due to its bioaccumulation. In order to remove NP, a series of MIL-100(Fe)/ZnFe2O4/flake-like porous carbon nitride (MIL/ZC) was synthesized through in-situ synthesis at room temperature. High performance of ternary MIL/ZC is used to degrade NP under visible light irradiation. The results show that 30MIL/ZC2 (20 wt.% ZnFe2O4) ternary composite had the best photocatalytic activity (99.84%) when the dosage was 30 mg. Further mechanism analysis shows that the excellent photocatalytic activity of 30MIL/ZC2 could be ascribed to the double charge transfer process between flake-like porous carbon nitride (PCN) and other catalysts in the ternary heterojunction, and the separation of photogenerated electron-hole pairs was more effective. In addition, the 30MIL/ZC2 also showed high stability after five cycles of the photodegradation reaction. Furthermore, the active substance (•O2-) was considered to be the main active substance in the NP degradation process. Based on the research results, the possible photocatalytic reaction mechanism of 30MIL/ZC2 ternary composite was proposed and discussed in detail.
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163
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Zhao Y, Li L, Zuo Y, He G, Chen Q, Meng Q, Chen H. Reduced graphene oxide supported ZnO/CdS heterojunction enhances photocatalytic removal efficiency of hexavalent chromium from aqueous solution. CHEMOSPHERE 2022; 286:131738. [PMID: 34388437 DOI: 10.1016/j.chemosphere.2021.131738] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/12/2021] [Accepted: 07/28/2021] [Indexed: 06/13/2023]
Abstract
The removal of toxic and harmful heavy metal contaminants from wastewater is of great importance for global environmental health. The development of efficient photocatalysts is attracting increasing interest with a current focus on material design for improved efficiency. Accordingly, this study aims to optimize the conformation of nanocomposite prepared from a CdS/ZnO heterojunction on reduced graphene oxide (RGO) for boosting the photocatalytic removal of heavy metal contaminants of aqueous systems. Under visible light, the candidate nanocomposites exhibited a range of photocatalytic activity in reducing hexavalent chromium [Cr(VI)] to trivalent chromium [Cr(III)] at room temperature. Among these different nanocomposites, the photocatalytic removal rate constant of Cr(VI) ranged as follows: ZnO/CdS6:5/RGO6 (0.106 min-1) > ZnO/CdS6:5 (0.0630 min-1) > CdS (0.0335 min-1) > ZnO (0.00121 min-1). Moreover, after five cycles of use, the photocatalytic reduction rate of ZnO/CdS6:5/RGO6 was 93.2 %, which signifies its strong re-cycling performance. These results reveal the feasibility of using CdS/ZnO6:5/RGO6 to reduce heavy metal ions from wastewater and provide insights for efficiently removing heavy metal ions without additional chemical trapping agents in the photocatalytic process.
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164
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Zhang Y, Zhao Y, Xiong Z, Gao T, Xiao R, Liu P, Liu J, Zhang J. Photo- and thermo-catalytic mechanisms for elemental mercury removal by Ce doped commercial selective catalytic reduction catalyst (V 2O 5/TiO 2). CHEMOSPHERE 2022; 287:132336. [PMID: 34826952 DOI: 10.1016/j.chemosphere.2021.132336] [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: 07/08/2021] [Revised: 09/03/2021] [Accepted: 09/21/2021] [Indexed: 06/13/2023]
Abstract
The elemental mercury was catalytically removed by V2O5/TiO2 and Ce doped V2O5/TiO2 catalysts under the UV irradiation at 30-160 °C to determine whether the catalysts could simultaneously have both thermo- and photo-catalytic activities. The physicochemical properties of catalysts were characterized by XRD, SEM, EDX, BET, XPS, UV-visible, PER and EIS. The experimental results demonstrated that V2O5/TiO2 and Ce-doped catalysts possessed both thermo- and photo-catalytic reactivities. A suitable reaction temperature (120 °C) and UV light had promoting effects on mercury removal efficiency. In addition, owing to the high oxidation capability as well good oxygen storage performance of Ce4+, Ce doping could greatly improve the mercury removal properties of the catalyst, reduce the inhibition of SO2 and make NO the component with enhanced effect. Ce doping also had the capability of enhancing the light absorption intensity in the UV region as well as the separation rate of photoinduced carriers. Finally, DFT calculations of V-Ti and Ce-V-Ti for Hg0 removal were investigated to further verify the experimental conclusion.
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165
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Jiang B, Bai J, Li L, He N, Zhang Q, Wang B, Tang D. Boosting power density of photocatalytic fuel cells with integrated supercapacitive photoanode. CHEMOSPHERE 2022; 286:131657. [PMID: 34351279 DOI: 10.1016/j.chemosphere.2021.131657] [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: 05/17/2021] [Revised: 06/24/2021] [Accepted: 07/21/2021] [Indexed: 06/13/2023]
Abstract
The photocatalytic fuel cell (PFC) is a promising energy conversion technology for effective solar energy utilization, wastewater treatment, and electricity generation by photoelectrochemical reactions. Nevertheless, the discharging current output and stability of the PFC are still plagued by the low photoelectron conversion efficiency and time-varying light intensity, respectively. Herein, we integrated a RuO2 capacitive layer and a TiO2 photocatalytic layer into a capacitive photoanode, finally designing a PFC with the capacitive photoanode. Not only can the successful integration of the capacitive layer augment the discharging current, but it can also balance the solar intensity fluctuation by the ability of electron storage. The capacitive photoanode showed a high areal capacitance of 1040.7 mFcm-2 at a current density of 0.5 mAcm-2, was continuously charged and discharged for 1000 cycles, and maintained 87 % of the original capacitance after cycles. The superior rate capability, high capacitance, and good cycle performance of the capacitive photoanode originate from the "crack mud" structure in the capacitive layer. The discharging current of the capacitive photoanode was 32.0 mAcm-2 under one sun illumination, and the electrochemical performance of the capacitive photoanode was better than that of the conventional TiO2 photoanode. The capacitive photoanode PFC possessed a maximum short-circuit current of 300.0 μA⋅cm-2 at the beginning of discharge, which is independent of the light intensity. The capacitive photoanode PFC adopts a new working mode and provides a unique solution for the practical application of PFC.
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Liu J, Lin H, Dong Y, He Y, Liu C. MoS 2 nanosheets loaded on collapsed structure zeolite as a hydrophilic and efficient photocatalyst for tetracycline degradation and synergistic mechanism. CHEMOSPHERE 2022; 287:132211. [PMID: 34826913 DOI: 10.1016/j.chemosphere.2021.132211] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 09/05/2021] [Accepted: 09/07/2021] [Indexed: 05/14/2023]
Abstract
In this study, MoS2@Z photocatalysts were synthesized by combining ultrasonic and hydrothermal methods, and used for the degradation of tetracycline. The structure characteristics and photocatalytic degradation mechanism of photocatalysts were also systematically investigated. The obtained MoS2@Z-5 exhibits the highest photo-degradation efficiency of tetracycline (87.23%), which is 3.58 times more than alkali-modified zeolite (24.34%) and 1.80 times more than pure MoS2 (48.53%). Furthermore, the MoS2@Z-5 showed significant stability in three times photocatalytic recycles and the removal efficiency only decrease by 9.03%. Crystal structure and micromorphology analysis show modified zeolite with collapsed structure can regulate the morphology of nano-MoS2 and make MoS2 appear fault structure, which can expose more active sites. In addition, low Si/Al ratio zeolite increases the hydrophilia of MoS2@Z-5. Reactive-species-trapping experiments show that the hole is the main reactive oxidizing species. The superior photo-degradation efficiency is mainly attributed to outstanding hydrophilia, exposure of the edge active sites, and efficient separation of photogenerated charge and holes. A possible photocatalytic mechanism and degradation pathways of tetracycline were proposed. The results indicate that MoS2@Z-5 may become an efficient, stable, and promising photocatalyst in tetracycline wastewater treatment.
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Parra-Ortiz E, Malmsten M. Photocatalytic nanoparticles - From membrane interactions to antimicrobial and antiviral effects. Adv Colloid Interface Sci 2022; 299:102526. [PMID: 34610862 DOI: 10.1016/j.cis.2021.102526] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 09/24/2021] [Accepted: 09/24/2021] [Indexed: 12/23/2022]
Abstract
As a result of increasing resistance among pathogens against antibiotics and anti-viral therapeutics, nanomaterials are attracting current interest as antimicrobial agents. Such materials offer triggered functionalities to combat challenging infections, based on either direct membrane action, effects of released ions, thermal shock induced by either light or magnetic fields, or oxidative photocatalysis. In the present overview, we focus on photocatalytic antimicrobial effects, in which light exposure triggers generation of reactive oxygen species. These, in turn, cause oxidative damage to key components in bacteria and viruses, including lipid membranes, lipopolysaccharides, proteins, and DNA/RNA. While an increasing body of studies demonstrate that potent antimicrobial effects can be achieved by photocatalytic nanomaterials, understanding of the mechanistic foundation underlying such effects is still in its infancy. Addressing this, we here provide an overview of the current understanding of the interaction of photocatalytic nanomaterials with pathogen membranes and membrane components, and how this translates into antibacterial and antiviral effects.
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168
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Vasseghian Y, Dragoi EN, Almomani F, Le VT. Graphene-based materials for metronidazole degradation: A comprehensive review. CHEMOSPHERE 2022; 286:131727. [PMID: 34352554 DOI: 10.1016/j.chemosphere.2021.131727] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 07/21/2021] [Accepted: 07/28/2021] [Indexed: 06/13/2023]
Abstract
Due to its cytotoxic effect, metronidazole (MNZ) is a drug commonly used to treat bacterial, protozoal, and microaerophilic bacterial infections. After consumption, it undergoes a series of metamorphic reactions that lead to the degradation of oxidized, acetylated, and hydrolyzed metabolites in the environment. To eliminate such pollutants, due to their high potential, adsorption and photocatalysis extensive processes are used in which graphene can be used to improve efficiency. This review analyses the use of graphene as an absorbent and catalyst with a focus on absorption and photocatalytic degradation of MNZ by graphene-based materials (GBMs). The parameters affecting the adsorption, and photocatalytic degradation of MNZ are investigated and discussed. Besides, the basic mechanisms occurring in these processes are summarized and analyzed. This work provides a theoretical framework that can direct future research in the field of MNZ removal from aqueous solutions.
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169
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Fan G, Chen C, Chen X, Li Z, Bao S, Luo J, Tang D, Yan Z. Enhancing the antifouling and rejection properties of PVDF membrane by Ag 3PO 4-GO modification. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 801:149611. [PMID: 34428657 DOI: 10.1016/j.scitotenv.2021.149611] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 08/02/2021] [Accepted: 08/08/2021] [Indexed: 06/13/2023]
Abstract
Ultrafiltration is an environmentally friendly water treatment technology, but membrane fouling significantly impacts membrane performance and service life. Photocatalytic modification of membrane is regarded as an effective way for membrane fouling control. In this study, graphite oxide (GO), Ag3PO4 and Ag3PO4-GO nanomaterials were applied in polyvinylidene fluoride (PVDF) ultrafiltration membranes modification, and the membranes was denoted as P-GO, P-AgP and P-AgP@GO, respectively. Filtration of humic acid (HA) at different operating conditions was adopted in evaluation of membrane performance. Among them, P-AgP@GO had the best permeation, rejection and antifouling performances, and could maintain excellent properties when operation conditions (HA concentration, operation pressure, pH and ionic strength) were changed. Furthermore, the effect of photocatalysis on the self-cleaning performance and its mechanism were revealed. The overall performance of P-AgP@GO could be enhanced by visible light irradiation, and extending the visible illumination time during the filtration was conducive to the reusability.
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170
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Teng M, Shi J, Qi H, Shi C, Wang W, Kang F, Eqi M, Huang Z. Effective enhancement of electron migration and photocatalytic performance of nitrogen-rich carbon nitride by constructing fungal carbon dot/molybdenum disulfide cocatalytic system. J Colloid Interface Sci 2021; 609:592-605. [PMID: 34848061 DOI: 10.1016/j.jcis.2021.11.060] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 11/11/2021] [Accepted: 11/12/2021] [Indexed: 12/11/2022]
Abstract
To find a cocatalyst that can replace noble metals, fungal carbon dot (CD) modified molybdenum disulfide (MoS2) cocatalyst system was designed. The composites were prepared by hydrothermal and calcination methods with different ratios of CDs, MoS2 and nitrogen-rich carbon nitride (p-C3N5). p-C3N5 has excellent electronic properties, and MoS2 modified by CDs (D-MoS2) can significantly enhance the photocatalytic performance of p-C3N5 by improving the photogenerated electron migration efficiency. The experiments showed that the developed CDs/MoS2/C3N5 composites exhibited excellent performance in both photocatalytic hydrogen (H2) evolution and methylene blue (MB) degradation, with CMSCN5 (D-MoS2 with 5% mass fraction) showing the best photocatalytic activity. The corresponding H2 evolution rate of CMSCN5 was 444 μmol g-1h-1 and 1.45 times higher than that of unmodified p-C3N5, by 120 min, the removal rate of MB was up to 93.51%. The 5 cycle tests showed that CMSCN5 had great stability. The high charge mobility and high density of H2 evolution active sites of MoS2 nanosheets, together with the electron storage and transfer properties of CDs can obviously improve electron migration and reduce the photogenerated carrier recombination on the p-C3N5 surface. The design and preparation of such composites offer broad prospects for the development of photocatalytic systems with noble metal-free cocatalysts.
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Xie J, Wang R, Li Y, Ni Z, Situ W, Ye S, Song X. A novel Ag 2O-TiO 2-Bi 2WO 6/polyvinyl alcohol composite film with ethylene photocatalytic degradation performance towards banana preservation. Food Chem 2021; 375:131708. [PMID: 34922276 DOI: 10.1016/j.foodchem.2021.131708] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 10/31/2021] [Accepted: 11/26/2021] [Indexed: 11/04/2022]
Abstract
In this research, the Ag2O-TiO2-Bi2WO6(ATB) ternary heterojunction photocatalyst was synthesized by hydrothermal and surface deposition method, and the ATB/PVA composite film with ethylene photocatalytic degradation performance was constructed by the casting method. The structure and properties of ATB and ATB/PVA films were characterized and applied to banana preservation. The results showed that the addition of ATB could improve the mechanical properties, thermal stability, oxygen and moisture resistance, and reduce the crystallinity and light transmittance of PVA films. Compared with TiO2, Bi2WO6 and TB photocatalysts, ATB had the best photocatalytic degradation effect of ethylene under LED light. Compared with blank group, the ethylene concentration decreased by 17.17%. This was mainly attributed to the formation of heterostructure among Ag2O, TiO2 and Bi2WO6, which promoted the separation and transfer of photogenerated carriers. The ATB/PVA composite coating could effectively prevent the respiration of the bananas by inhibiting gas exchange and degrading ethylene, which reduced the weight loss, inhibited glycogen decomposition, improved the pulp hardness, increased titratable acid content, reduced the PPO activity, hindered the phenol oxidation and keep better apparent color of bananas. The safety study suggested that the ATB/PVA film is safe for bananas packaging application.
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Chen Z, He Z, Zhou M, Xie M, He T, Zhao Y, Chen X, Wu Y, Xu Z. In-situ synthesis of biochar modified PbMoO 4: An efficient visible light-driven photocatalyst for tetracycline removal. CHEMOSPHERE 2021; 284:131260. [PMID: 34182280 DOI: 10.1016/j.chemosphere.2021.131260] [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: 11/30/2020] [Revised: 04/13/2021] [Accepted: 06/15/2021] [Indexed: 05/27/2023]
Abstract
For highly efficient photocatalytic remediation of organic pollutants, broad-spectrum light response and effective charge separation are two key goals. To achieve these goals, a novel biochar (BC) modified PbMoO4 composite catalyst was successfully synthesized in situ by combining coprecipitation with pyrolysis treatment of poplar sawdust and the technical feasibility of degradation of tetracycline (TC) with compound photocatalyst prepared from recovered agricultural and forestry residues was preliminarily demonstrated. The characterization demonstrated that the presence of BC narrowed the bandgap, enhanced visible light absorption as well as facilitated charge separation. Three composites (with the mass ratio of PbMoO4 to BC = 1:4; 1:1; and 4:1, respectively) displayed higher activity than pure PbMoO4. The results showed that the composite with the PbMoO4 to BC ratio of 1:4 exhibited the best photocatalytic activity, for 150 mg L-1 TC the removal rate was 61.0%, and the rate constant was 8.1 × 10-3 min-1, while the photocatalytic activity of PbMoO4 was 26.0% and 3.9 × 10-3 min-1. The reactions in the presence of radical quenchers indicated that holes (h+) and superoxide radicals (O2-) were the dominant active species for photodegradation. In different water matrices, for 150 mg L-1 TC solution the photocatalytic activity of optimal photocatalyst decreased as follows: ultrapure water > artificial sewage > farm sewage > municipal sewage. Moreover, the catalyst exhibited good stability over five cycles. Therefore, BC doped PbMoO4 provides a useful strategy for improving the photocatalytic ability of PbMoO4-based photocatalysts and offers a promising method for water purification.
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Liu Y, Ma X, Jin Z. Engineering a NiAl-LDH/CoS x S-Scheme heterojunction for enhanced photocatalytic hydrogen evolution. J Colloid Interface Sci 2021; 609:686-697. [PMID: 34836652 DOI: 10.1016/j.jcis.2021.11.065] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 11/12/2021] [Accepted: 11/13/2021] [Indexed: 10/19/2022]
Abstract
The use of semiconductors to construct heterojunctions to suppress the rapid recombination of photogenerated charges and holes is considered to be an effective way to improve the efficiency of photocatalytic hydrogen evolution. Herein, cobalt sulfide (CoSx) nanoparticles are cultivated in situ in the folds of three-dimensional flower-like nickel-aluminium layered double hydroxides (NiAl-LDHs) using a facile solvothermal method. The hydrogen production rate of the binary CoSx/NiAl-LDH heterojunction reaches 3678.59 μmol/g/h, which is 83.74 and 22 times the rates of CoSx and NiAl-LDH, respectively. The unique three-dimensional structure of NiAl-LDH facilitates the growth of CoSx and shortens the transfer pathway of photogenerated electrons. More importantly, the built-in electric field formed at the interface and the S-type charge transport mechanism caused by the bending of the energy band enhance not only charge separation but also maintain the strong oxidation ability of the holes. In this study, the newly designed S-scheme heterojunction offers a new strategy for enhancing photocatalytic water splitting.
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Tian H, Luo J, Zhang K, Ma C, Qi Y, Zhan S, Liu X, Li M, Liu H. Synergistic Photocatalytic-Adsorption Removal of Basic Magenta Effect of AgZnO/Polyoxometalates Nanocomposites. NANOSCALE RESEARCH LETTERS 2021; 16:163. [PMID: 34757523 PMCID: PMC8581081 DOI: 10.1186/s11671-021-03620-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 10/27/2021] [Indexed: 05/26/2023]
Abstract
The bifunctional photocatalytic-adsorbent AgZnO/polyoxometalates (AgZnO/POMs) nanocomposites were synthesized by combining AgZnO hybrid nanoparticles and polyoxometalates [Cu(L)2(H2O)]H2[Cu(L)2(P2Mo5O23)]⋅4H2O (HL = C6H6N2O) into nanostructures via a sonochemical method. Transmission electron microscopy (TEM) indicated that AgZnO/POMs nanocomposites were uniform with narrow particle size distribution and without agglomeration. X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis confirmed the nanostructure and composition of AgZnO/POMs nanocomposites. The ultraviolet-visible spectra (UV-Vis) and photoluminescence spectra (PL) confirmed excellent optical properties of the AgZnO/POMs nanocomposites. 94.13% ± 0.61 of basic magenta (BM) in aqueous solution could be removed using the AgZnO/POMs nanocomposites through adsorption and photocatalysis. The kinetic analysis showed that both the adsorption and photocatalysis process conform to pseudo-second-order kinetics. In addition, the removal rate of AgZnO/POMs nanocomposites was found to be almost unchanged after 5 cycles of use. The bifunctional photocatalytic-adsorbent AgZnO/POMs nanocomposites with high stability and cycling performance have broad application prospects in the treatment of refractory organic dye wastewater containing triphenylmethane.
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Xu S, Chang L, Hu Y, Zhao X, Huang S, Chen Z, Ren X, Mei X. Tea polyphenol modified, photothermal responsive and ROS generative black phosphorus quantum dots as nanoplatforms for promoting MRSA infected wounds healing in diabetic rats. J Nanobiotechnology 2021; 19:362. [PMID: 34758829 PMCID: PMC8579683 DOI: 10.1186/s12951-021-01106-w] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 10/26/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Healing of MRSA (methicillin-resistant Staphylococcus aureus) infected deep burn wounds (MIDBW) in diabetic patients remains an obstacle but is a cutting-edge research problem in clinical science. Surgical debridement and continuous antibiotic use remain the primary clinical treatment for MIDBW. However, suboptimal pharmacokinetics and high doses of antibiotics often cause serious side effects such as fatal complications of drug-resistant bacterial infections. MRSA, which causes wound infection, is currently a bacterium of concern in diabetic wound healing. In more severe cases, it can even lead to amputation of the patient's limb. The development of bioactive nanomaterials that can promote infected wound healing is significant. RESULTS The present work proposed a strategy of using EGCG (Epigallocatechin gallate) modified black phosphorus quantum dots (BPQDs) as therapeutic nanoplatforms for MIDBW to achieve the synergistic functions of NIR (near-infrared)-response, ROS-generation, sterilization, and promoting wound healing. The electron spin resonance results revealed that EGCG-BPQDs@H had a more vital photocatalytic ability to produce singlet oxygen than BPQDs@H. The inhibition results indicated an effective bactericidal rate of 88.6% against MRSA. Molecular biology analysis demonstrated that EGCG-BPQDs significantly upregulated CD31 nearly fourfold and basic fibroblast growth factor (bFGF) nearly twofold, which were beneficial for promoting the proliferation of vascular endothelial cells and skin epidermal cells. Under NIR irradiation, EGCG-BPQDs hydrogel (EGCG-BPQDs@H) treated MIDBW area could rapidly raise temperature up to 55 °C for sterilization. The MIBDW closure rate of rats after 21 days of treatment was 92.4%, much better than that of 61.1% of the control group. The engineered EGCG-BPQDs@H were found to promote MIDBW healing by triggering the PI3K/AKT and ERK1/2 signaling pathways, which could enhance cell proliferation and differentiation. In addition, intravenous circulation experiment showed good biocompatibility of EGCG-BPQDs@H. No significant damage to major organs was observed in rats. CONCLUSIONS The obtained results demonstrated that EGCG-BPQDs@H achieved the synergistic functions of photocatalytic property, photothermal effects and promoted wound healing, and are promising multifunctional nanoplatforms for MIDBW healing in diabetics.
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