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Ab initio molecular dynamics of solvation effects and reactivity at the interface between water and ascorbic acid covered anatase TiO 2 (101). Chemphyschem 2024; 25:e202300768. [PMID: 38153248 DOI: 10.1002/cphc.202300768] [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: 10/17/2023] [Revised: 12/16/2023] [Accepted: 12/28/2023] [Indexed: 12/29/2023]
Abstract
In this work, we present a detailed study of the interaction between ascorbic acid (L-asc) and anatase TiO2 (101) surface both in gas phase and in contact with water by using density functional theory and ab initio molecular dynamics simulations. In gas phase, L-asc strongly binds the TiO2 (101) surface as a dianion (L-asc2- ), adopting a bridging bidentate coordination mode (BB), with the two acid protons transferred to two surface 2-fold bridging oxygens (O2c). AIMD simulations show that the interaction between the organic ligand and the anatase surface is stable and comparable to the vacuum one despite the possible solvent effects and/or possible structural distortions of the ligand. In addition, during the AIMD simulations hydroxylation phenomena occur forming transient H3 O+ ions at the solid-liquid interface. For the first time, our results provide insight into the role of the ascorbic acid on the electronic properties of the TiO2 (101), the influence of the water environment on the ligand-surface interaction and the nature of the solid-liquid interface.
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Property-governed performance of platinum-modified titania photocatalysts. Front Chem 2022; 10:972494. [PMID: 36212069 PMCID: PMC9538187 DOI: 10.3389/fchem.2022.972494] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Accepted: 09/05/2022] [Indexed: 11/13/2022] Open
Abstract
Titania is probably the most widely investigated semiconductor photocatalyst because of various advantages, such as high activity, thermal and chemical stability, low price, abundance, and negligible toxicity. However, pristine titania is also characterized by charge carriers’ recombination, and thus lower quantum yields of photocatalytic reactions than theoretical 100%. Moreover, its wide bandgap, despite being recommended for excellent redox properties, means also inactivity under visible part of solar radiation. Accordingly, titania has been surface modified, doped and coupled with various elements/compounds. For example, platinum deposited on the surface of titania has shown to improve both UV activity and the performance under vis. Although the studies on titania modification with platinum started almost half a century ago, and huge number of papers have been published up to now, it is unclear which properties are the most crucial and recommended to obtain highly efficient photocatalyst. In the literature, the opposite findings could be found on the property-governed activities that could result from huge differences in the reaction systems, and also examined photocatalysts. Considering the platinum properties, its content, the size of nanoparticles and the oxidation state, must be examined. Obviously, the characteristics of titania also influence the resultant properties of deposited platinum, and thus the overall photocatalytic performance. Although so many reports on Pt/TiO2 have been published, it is hardly possible to give indispensable advice on the recommended properties. However, it might be concluded that usually fine platinum NPs uniformly deposited on the titania surface result in high photocatalytic activity, and thus in the low optimal content of necessary platinum. Moreover, the aggregation of titania particles might also help in the lowering the necessary platinum amount (even to 0.2 wt%) due to the interparticle electron transfer mechanism between titania particles in one aggregate. In respect of platinum state, it is thought that it is highly substrate-specific case, and thus either positively charged or zero valent platinum is the most recommended. It might be concluded that despite huge number of papers published on platinum-modified titania, there is still a lack of comprehensive study showing the direct correlation between only one property and the resultant photocatalytic activity.
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Femtochemistry methods for studying the photophysics and photochemistry of halide complexes of platinum metals. Russ Chem Bull 2022. [DOI: 10.1007/s11172-022-3486-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Nano Metal-Containing Photocatalysts for the Removal of Volatile Organic Compounds: Doping, Performance, and Mechanisms. NANOMATERIALS 2022; 12:nano12081335. [PMID: 35458043 PMCID: PMC9027785 DOI: 10.3390/nano12081335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 04/10/2022] [Accepted: 04/11/2022] [Indexed: 12/10/2022]
Abstract
Volatile organic compounds (VOCs) in indoor air are considered a major threat to human health and environmental safety. The development of applicable technologies for the removal of VOCs is urgently needed. Nowadays, photocatalytic oxidation (PCO) based on metal-containing photocatalysts has been regarded as a promising method. However, unmodified photocatalysts are generally limited in applications because of the narrow light response range and high recombination rate of photo-generated carriers. As a result, nano metal-containing photocatalysts doped with elements or other materials have attracted much attention from researchers and has developed over the past few decades. In addition, different doping types cause different levels of catalyst performance, and the mechanism for performance improving is also different. However, there are few reviews focusing on this aspect, which is really important for catalyst design and application. This work aims to give a comprehensive overview of nano metal-containing photocatalysts with different doping types for the removal of VOCs in an indoor environment. First, the undoped photocatalysts and the basic mechanism of PCO is introduced. Then, the application of metal doping, non-metal doping, co-doping, and other material doping in synthetic metal-containing photocatalysts are discussed and compared, respectively, and the synthesis methods, removal efficiency, and mechanisms are further investigated. Finally, a development trend for using nano metal-containing photocatalysts for the removal of VOCs in the future is proposed. This work provides a meaningful reference for selecting effective strategies to develop novel photocatalysts for the removal of VOCs in the future.
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Fight against COVID-19: The case of antiviral surfaces. APL MATERIALS 2021; 9:031112. [PMID: 33842101 PMCID: PMC8017599 DOI: 10.1063/5.0043009] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 02/18/2021] [Indexed: 05/05/2023]
Abstract
The COVID-19 pandemic is the largest global public health outbreak in the 21st century so far. Based on World Health Organization reports, the main source of SARS-CoV-2 infection is transmission of droplets released when an infected person coughs, sneezes, or exhales. Viral particles can remain in the air and on the surfaces for a long time. These droplets are too heavy to float in air and rapidly fall down onto the surfaces. To minimize the risk of the infection, entire surrounding environment should be disinfected or neutralized regularly. Development of the antiviral coating for the surface of objects that are frequently used by the public could be a practical route to prevent the spread of the viral particles and inactivation of the transmission of the viruses. In this short review, the design of the antiviral coating to combat the spread of different viruses has been discussed and the technological attempts for minimizing the coronavirus outbreak have been highlighted.
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Abatement of formaldehyde with photocatalytic and catalytic oxidation: a review. INTERNATIONAL JOURNAL OF CHEMICAL REACTOR ENGINEERING 2020. [DOI: 10.1515/ijcre-2020-0003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Formaldehyde is one of the vital chemicals produced by industries, transports, and domestic products. Formaldehyde emissions adversely affect human health and it is well known for causing irritation and nasal tumors. The major aim of the modern indoor formaldehyde control study is in view of energy capacity, product selectivity, security, and durability for efficient removal of formaldehyde. The two important methods to control this harmful chemical in the indoor environments are photocatalytic oxidation and catalytic oxidation with noble metals and transition metal oxides. By harmonizing different traditional photocatalytic and catalytic oxidation technologies that have been evolved already, here we give a review of previously developed efforts to degrade indoor formaldehyde. The major concern in this article is based on getting the degradation of formaldehyde at ambient temperature. In this article, different aspects of these two methods with their merits and demerits are discussed. The possible effects of operating parameters like preparation methods, support, the effect of light intensity in photocatalytic oxidation, relative humidity, etc. have been discussed comprehensively.
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Enhanced photocatalytic and antibacterial activities of mechanosynthesized TiO2–Ag nanocomposite in wastewater treatment. J Mol Struct 2020. [DOI: 10.1016/j.molstruc.2020.128076] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Thermal atomic layer deposition of gold nanoparticles: controlled growth and size selection for photocatalysis. NANOSCALE 2020; 12:9005-9013. [PMID: 32270836 DOI: 10.1039/d0nr01092h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Gold nanoparticles have been extensively studied for their applications in catalysis. For Au nanoparticles to be catalytically active, controlling the particle size is crucial. Here we present a low temperature (105 °C) thermal atomic layer deposition approach for depositing gold nanoparticles on TiO2 with controlled size and loading using trimethylphosphino-trimethylgold(iii) and two co-reactants (ozone and water) in a fluidized bed reactor. We show that the exposure time of the precursors is a variable that can be used to decouple the Au particle size from the loading. Longer exposures of ozone narrow the particle size distribution, while longer exposures of water broaden it. By studying the photocatalytic activity of Au/TiO2 nanocomposites, we show how the ability to control particle size and loading independently can be used not only to enhance performance but also to investigate structure-property relationships. This study provides insights into the mechanism underlying the formation and evolution of Au nanoparticles prepared for the first time via vapor phase atomic layer deposition. Employing a vapor deposition technique for the synthesis of Au/TiO2 nanocomposites eliminates the shortcomings of conventional liquid-based processes opening up the possibility of highly controlled synthesis of materials at large scale.
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Rhodium nanoparticles impregnated on TiO 2: strong morphological effects on hydrogen production. NEW J CHEM 2020. [DOI: 10.1039/d0nj02419h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Rhodium nanoparticles with different morphology were synthesized to assess the influence of the exposed facet towards hydrogen production in aqueous methanolic solution.
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Quantum chemistry of OsCl62− photoaquation products and the reaction scheme. Photochem Photobiol Sci 2019; 18:1122-1129. [DOI: 10.1039/c8pp00553b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The mechanism of formation of the hydroxocomplex OsIVCl5(OH)2− after photoexcitation of OsIVCl62−.
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11
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Mechanism of chain photochemical reaction of ( n -Bu 4 N) 2 [PtCl 6 ] in chloroform. J Photochem Photobiol A Chem 2018. [DOI: 10.1016/j.jphotochem.2018.03.038] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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12
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Modeling of acid dye decolorization by TiO2–Ag2O nano-photocatalytic process using response surface methodology. JOURNAL OF SAUDI CHEMICAL SOCIETY 2017. [DOI: 10.1016/j.jscs.2015.07.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Enhanced photocatalytic degradation of atrazine by platinized titanium dioxide under 352 nm irradiation. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2017; 75:1128-1137. [PMID: 28272041 DOI: 10.2166/wst.2016.593] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Simply coating 1 wt.% of platinum on titanium dioxide (TiO2) surface resulted in simple preparation of platinized TiO2 (Pt-TiO2). This study demonstrated the photodegradation of atrazine (ATZ) using either Pt-TiO2 or TiO2 as a photocatalyst under 352 nm light irradiation. The Pt-TiO2-catalyzed ATZ degradation reached 76% in 3 hours without adding H2O2 solution or aeration, which was more than 10% higher than the TiO2-catalyzed reaction. The decomposition product of Pt-TiO2-catalyzed ATZ degradation was mainly cyanuric acid. Thus, Pt-TiO2 as an effective photocatalyst has three main advantages in the photodegradation of ATZ under 352 nm irradiation. First, the coated Pt can facilitate the generation of appropriate amounts of OH radicals, so it can prevent the formation of over-oxidized TiO2. Second, aeration was not needed. Third, the excited electrons were mainly uni-directionally transferred to the catalyst surface to avoid recombination of electron-hole pairs.
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Towards a large scale aqueous sol-gel synthesis of doped TiO2: Study of various metallic dopings for the photocatalytic degradation of p-nitrophenol. J Photochem Photobiol A Chem 2016. [DOI: 10.1016/j.jphotochem.2016.06.029] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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17
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Efficiently Enhancing Visible Light Photocatalytic Activity of Faceted TiO2 Nanocrystals by Synergistic Effects of Core-Shell Structured Au@CdS Nanoparticles and Their Selective Deposition. ACS APPLIED MATERIALS & INTERFACES 2016; 8:21326-33. [PMID: 27479634 DOI: 10.1021/acsami.6b05563] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Integrating wide bandgap semiconductor photocatalysts with visible-light-active inorganic nanoparticles (such as Au and CdS) as sensitizers is one of the most efficient methods to improve their photocatalytic activity in the visible light region. However, as for all such composite photocatalysts, a rational design and precise control over their architecture is often required to achieve optimal performance. Herein, a new TiO2-based ternary composite photocatalyst with superior visible light activity was designed and synthesized. In this composite photocatalyst, the location of the visible light sensitizers was engineered according to the intrinsic facet-induced effect of well-faceted TiO2 nanocrystals on the spatial separation of photogenerated carriers. Experimentally, core-shell structured Au@CdS nanoparticles acting as visible light sensitizers were selectively deposited onto photoreductive {101} facets of well-faceted anatase TiO2 nanocrystals through a two-step in situ photodeposition route. Because the combination of Au@CdS and specific {101} facets of TiO2 nanocrystals facilitates the transport of charges photogenerated under visible light irradiation, this well-designed ternary composite photocatalyst exhibited superior activity in visible-light-driven photocatalytic H2 evolution, as expected.
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The role of iron functionalization on the visible-light photocatalytic performance of TiO2 nanofibers suitable for environmental applications. RESEARCH ON CHEMICAL INTERMEDIATES 2016. [DOI: 10.1007/s11164-016-2595-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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20
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Primary photophysical and photochemical processes upon UV excitation of PtBr6 2– and PtCl6 2– complexes in water and methanol. Russ Chem Bull 2016. [DOI: 10.1007/s11172-015-1072-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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21
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Photochemistry of the PtCl62– complex in acidic aqueous solutions. MENDELEEV COMMUNICATIONS 2016. [DOI: 10.1016/j.mencom.2016.01.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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22
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Recent advances in the synthesis and application of photocatalytic metal–metal oxide core–shell nanoparticles for environmental remediation and their recycling process. RSC Adv 2016. [DOI: 10.1039/c6ra18102c] [Citation(s) in RCA: 131] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Metal–metal oxide core–shell nanoparticles have received enormous research attention owing to their fascinating physicochemical properties and extensive applications. In this review we have discussed the challenges and recent advances in their synthesis and application.
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Primary reactions in the photochemistry of hexahalide complexes of platinum group metals: A minireview. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2015. [DOI: 10.1016/j.jphotochemrev.2015.05.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Photophysical and photochemical processes followed by 320nm femtosecond laser excitation of IrCl62− complex in aqueous and methanol solutions. J Photochem Photobiol A Chem 2014. [DOI: 10.1016/j.jphotochem.2014.07.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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25
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Nitrogen-Doped Titanium Dioxide as Visible-Light-Sensitive Photocatalyst: Designs, Developments, and Prospects. Chem Rev 2014; 114:9824-52. [DOI: 10.1021/cr5000738] [Citation(s) in RCA: 940] [Impact Index Per Article: 94.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Synthesis and photocatalytic activities of CdS/TiO₂ nanoparticles supported on carbon nanofibers for high efficient adsorption and simultaneous decomposition of organic dyes. J Colloid Interface Sci 2014; 434:159-66. [PMID: 25181331 DOI: 10.1016/j.jcis.2014.07.039] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 07/17/2014] [Accepted: 07/25/2014] [Indexed: 11/23/2022]
Abstract
CdS/TiO2 NPs-decorated carbon nanofibers were prepared by a simple electrospinning method followed by the calcination under argon atmosphere. As-synthesized nanocomposites exhibited a strong photocatalytic activity for decomposition of methylene blue (MB), reactive black 5, and reactive orange 16 under visible light radiation for many successive cycles. Moreover, in the dark, the carbon content revealed very good adsorption behavior as 95% of the dye was removed within 5 min, however less adsorption capacity was observed upon successive cycles. Therefore, the enhanced photocatalytic performance for the introduced nanofibers might be attributed to the adsorption characteristic of carbon nanofiber and the known photocatalytic activities of the TiO2 and CdS photocatalysts.
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Spectrophotometric evaluation of the photocatalytic degradation of formaldehyde by Fe2O3–TiO2 nano hybrid. J IND ENG CHEM 2014. [DOI: 10.1016/j.jiec.2013.08.040] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Enhanced photocatalytic activity of TiO₂-C hybrid aerogels for methylene blue degradation. Sci Rep 2013; 3:3018. [PMID: 24145581 PMCID: PMC3804859 DOI: 10.1038/srep03018] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 10/04/2013] [Indexed: 11/24/2022] Open
Abstract
Carbon-based TiO2 composites have many advantages as photocatalysts. However, they suffer from low light efficiency due to the low contrast of TiO2 with carbon. We synthesized a novel type of anatase-type TiO2-C hybrid aerogel by a one-pot sol-gel method, which shows a photocatalytic activity for methylene degradation up to 4.23 times that of P25, a commercial photocatalyst from Degussa Inc. The hybrid aerogels are prepared from TiCl4 and resorcinol–furfural, and have a tunable macropore size from 167 to 996 nm. They are formed of submicrometer particles that consist of interwoven anatase and carbon nanoparticles. The anatase nanoparticles have a size of 8–9 nm and a tunable oxygen vacancy from 7.2 to 18.0%. The extremely high activity is ascribed to the large light absorption caused by macropore scattering and oxygen vacancies in the anatase. These findings may open up a new avenue and stimulate further research to improve photocatalytic performance.
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31
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An enhanced visible-light photocatalytic activity of TiO2 by nitrogen and nickel–chlorine modification. Sep Purif Technol 2013. [DOI: 10.1016/j.seppur.2012.11.030] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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32
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Amorphous TiO2coated into periodic mesoporous organosilicate channels as a new binary photocatalyst for regeneration of carbonyl compounds from oximes under sunlight irradiation. Org Biomol Chem 2013. [DOI: 10.1039/c2ob26907d] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Photocatalytic oxidation of benzene, toluene, ethylbenzene and m-xylene in the gas-phase over TiO2-based catalysts. J Photochem Photobiol A Chem 2012. [DOI: 10.1016/j.jphotochem.2012.06.016] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Electrospun metal oxide-TiO2 nanofibers for elemental mercury removal from flue gas. JOURNAL OF HAZARDOUS MATERIALS 2012; 227-228:427-435. [PMID: 22703732 DOI: 10.1016/j.jhazmat.2012.05.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Revised: 04/30/2012] [Accepted: 05/01/2012] [Indexed: 06/01/2023]
Abstract
Nanofibers prepared by an electrospinning method were used to remove elemental mercury (Hg(0)) from simulated coal combustion flue gas. The nanofibers composed of different metal oxides (MO(x)) including CuO, In(2)O(3), V(2)O(5), WO(3) and Ag(2)O supported on TiO(2) have been characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersing X-ray (EDX) and UV-vis spectra. The average diameters of these nanofibers were about 200nm. Compared to pure TiO(2), the UV-vis absorption intensity for MO(x)-TiO(2) increased significantly and the absorption bandwidth also expanded, especially for Ag(2)O-TiO(2) and V(2)O(5)-TiO(2). Hg(0) oxidation efficiencies over the MO(x)-TiO(2) nanofibers were tested under dark, visible light (vis) irradiation and UV irradiation, respectively. The results showed that WO(3) doped TiO(2) exhibited the highest Hg(0) removal efficiency of 100% under UV irradiation. Doping V(2)O(5) into TiO(2) enhanced Hg(0) removal efficiency greatly from 6% to 63% under visible light irradiation. Ag(2)O doped TiO(2) showed a steady Hg(0) removal efficiency of around 95% without any light due to the formation of silver amalgam. An extended experiment with 8 Hg(0) removal cycles showed that the MO(x)-TiO(2) nanofibers were stable for removing Hg(0) from flue gas. Factors responsible for the enhanced photocatalytic activities of the MO(x)-TiO(2) nanofibers were also discussed.
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Promotion of phenol photodecomposition over TiO2 using Au, Pd, and Au-Pd nanoparticles. ACS NANO 2012; 6:6284-92. [PMID: 22663086 DOI: 10.1021/nn301718v] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Noble metal nanoparticles (Au, Pd, Au-Pd alloys) with a narrow size distribution supported on nanocrystalline TiO(2) (M/TiO(2)) have been synthesized via a sol-immobilization route. The effect of metal identity and size on the photocatalytic performance of M/TiO(2) has been systematically investigated using phenol as a probe molecule. A different phenol degradation pathway was observed when using M/TiO(2) catalysts as compared to pristine TiO(2). We propose a mechanism to illustrate how the noble metal nanoparticles enhance the efficiency of phenol decomposition based on photoreduction of p-benzoquinone under anaerobic conditions. Our results suggest that the metal nanoparticles not only play a role in capturing photogenerated electrons, but are strongly involved in the photocatalytic reaction mechanism. The analysis of the reaction intermediates allows us to conclude that on M/TiO(2) undesired redox reactions that consume photogenerated radicals are effectively suppressed. The analysis of the final products shows that the reusability performance of the catalyst is largely dependent on the pretreatment of the catalyst and the identity of the metal nanoparticle. Interestingly, the as-prepared Pd and Au-Pd decorated TiO(2) materials exhibit excellent long-term photoactivity, in which ~90% of the phenol can be fully decomposed to CO(2) in each cycle.
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Cr modified TiO2-loaded MCM-41 catalysts for UV-light driven photodegradation of diethyl sulfide and ethanol. J Photochem Photobiol A Chem 2012. [DOI: 10.1016/j.jphotochem.2012.01.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Enhanced photocatalytic cytotoxic activity of Ag@Fe-doped TiO2 nanocomposites against human epithelial carcinoma cells. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm15636a] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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39
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Visible light driven photocatalysis in chromate(VI)/TiO2 systems—Improving stability of the photocatalyst. Catal Today 2011. [DOI: 10.1016/j.cattod.2010.10.075] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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40
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Visible light photocatalysis by metal halide complexes containing titania as a semiconductor ligand. ADVANCES IN INORGANIC CHEMISTRY 2011. [DOI: 10.1016/b978-0-12-385904-4.00002-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Influence of Excitation Wavelength (UV or Visible Light) on the Photocatalytic Activity of Titania Containing Gold Nanoparticles for the Generation of Hydrogen or Oxygen from Water. J Am Chem Soc 2010; 133:595-602. [DOI: 10.1021/ja1086358] [Citation(s) in RCA: 876] [Impact Index Per Article: 62.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Abstract
This Perspective is focused on the photocatalytic activity of gold nanoparticles supported on titania (Au/TiO(2)). Titania is the most widely used photocatalyst, but its limited activity under visible light irradiation has motivated the quest for modified titania materials absorbing visible light. The review starts by justifying how doping with metallic elements is a related strategy, but different, to that leading to the use of Au/TiO(2) in photocatalysis. Data supporting and confirming the photoactivity of gold nanoparticles in colloidal solutions are briefly presented to justify the possibility of gold photosensitization of titania by electron injection into the conduction band. After describing the most common procedures used to prepare Au/TiO(2), the central part of this article is focused on the photocatalytic activity reported for Au/TiO(2) for hydrogen generation, dye decoloration, phenol decomposition and carboxylic acid degradation, among other processes. Emphasis is given to the role that parameters like Au loading, particle size, surface area, spatial structuring and others play on the photocatalytic activity. One important issue has been to distinguish those reports using visible light from those other in which direct titania excitation by UV light has been used. These Au/TiO(2) photocatalysts can find real applications in the near future for environmental remediation and for hydrogen generation.
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Recent advances in visible light-responsive titanium oxide-based photocatalysts. RESEARCH ON CHEMICAL INTERMEDIATES 2010. [DOI: 10.1007/s11164-010-0142-5] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Abstract
Titanium dioxide has received great attention both in fundamental and applied photocatalysis due to its low cost, non-toxicity, and stability against photocorrosion [ - ]. Unfortunately it can utilize only the very small UV part (about 3%) of solar light arriving at the earth surface. However, also the visible part (λ > 400 nm) may induce photocatalysis if titania is modified by transition or main group elements. Accordingly, many publications appeared in the last 20 years dealing with the problem of sensitizing titania for visible light photooxidation reactions. This may be achieved by doping, which means substitution of lattice ions, and by surface modification. In many cases authors not clearly differentiate between these two possibilities and so called doped titania quite often is a surface modified material. The latter is easily prepared by heating titania or its precursor compounds like titanium hydroxide in the presence of a modifier at temperatures in the range of 100 – 500 °C. In the following we summarize our work in this field using inorganic and organic sensitizers.
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Synthesis of TiO2–Ag nanocomposite with sol–gel method and investigation of its antibacterial activity against E. coli. POWDER TECHNOL 2009. [DOI: 10.1016/j.powtec.2009.07.021] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Photocatalytic degradation of Rhodamine B under visible light with Nd-doped titanium dioxide films. J RARE EARTH 2009. [DOI: 10.1016/s1002-0721(08)60326-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Development and potential of new generation photocatalytic systems for air pollution abatement: an overview. ASIA-PAC J CHEM ENG 2009. [DOI: 10.1002/apj.321] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Photo-oxidation of nitrogen oxide over titanium(IV) oxide modified with platinum or rhodium chlorides under irradiation of visible light or UV light. Catal Today 2009. [DOI: 10.1016/j.cattod.2008.12.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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