The Experts below are selected from a list of 14442 Experts worldwide ranked by ideXlab platform
Olga Solcova - One of the best experts on this subject based on the ideXlab platform.
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Wavelength Effect on Photocatalytic Reduction of CO2 by Ag/TiO2 Catalyst
Chinese Journal of Catalysis, 2011Co-Authors: K C, K. ZatloukalovÁ, A. HospodkovÁ, Z. Lacný, Sabina Krejčíková, Libor Čapek, Lucie Obalová, Olga SolcovaAbstract:Photocatalytic Reduction of CO2 by water was performed in the presence of a Ag/TiO2 catalyst under illumination by lamps with different wavelengths (254, 365, and 400 nm). The yields of the main products (methane and methanol) were higher with the 254 nm lamp than with the 365 lamp while no products were observed with the 400 nm lamp. This was because the electron-hole generation rate in- creased with increasing energy of irradiation (decreasing wavelength) and there were higher densities of electron states at higher energies in TiO2. The increased efficiency of electron-hole generation with a shorter wavelength irradiation increased the efficiency of the catalyst. The energy of the electrons excited by visible light (400 nm) was too low for CO2 Photocatalytic Reduction.
K C - One of the best experts on this subject based on the ideXlab platform.
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Wavelength Effect on Photocatalytic Reduction of CO2 by Ag/TiO2 Catalyst
Chinese Journal of Catalysis, 2011Co-Authors: K C, K. ZatloukalovÁ, A. HospodkovÁ, Z. Lacný, Sabina Krejčíková, Libor Čapek, Lucie Obalová, Olga SolcovaAbstract:Photocatalytic Reduction of CO2 by water was performed in the presence of a Ag/TiO2 catalyst under illumination by lamps with different wavelengths (254, 365, and 400 nm). The yields of the main products (methane and methanol) were higher with the 254 nm lamp than with the 365 lamp while no products were observed with the 400 nm lamp. This was because the electron-hole generation rate in- creased with increasing energy of irradiation (decreasing wavelength) and there were higher densities of electron states at higher energies in TiO2. The increased efficiency of electron-hole generation with a shorter wavelength irradiation increased the efficiency of the catalyst. The energy of the electrons excited by visible light (400 nm) was too low for CO2 Photocatalytic Reduction.
Omid Akhavan - One of the best experts on this subject based on the ideXlab platform.
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Visible light-induced Photocatalytic Reduction of graphene oxide by tungsten oxide thin films
Applied Surface Science, 2013Co-Authors: M. Choobtashani, Omid AkhavanAbstract:Abstract Tungsten oxide thin films (deposited by thermal evaporation or sol gel method) were used for Photocatalytic Reduction of graphene oxide (GO) platelets (synthesized through a chemical exfoliation method) on surface of the films under UV or visible light of the environment, in the absence of any aqueous ambient at room temperature. Atomic force microscopy (AFM) technique was employed to characterize surface morphology of the GO sheets and the tungsten oxide films. Moreover, using X-ray photoelectron spectroscopy (XPS), chemical state of the tungsten oxide films and the Photocatalytic Reduction of the GO platelets were quantitatively investigated. The better performance of the sol–gel tungsten oxide films in Photocatalytic Reduction of GO platelets as compared to the evaporated tungsten oxide films was assigned to lower W 5+ /W 6+ ratio (i.e., a better stoichiometry) and higher surface water content of the sol–gel film. The GO Reduction level achieved after 24 h UV-assisted Photocatalytic Reduction on surface of the sol–gel tungsten oxide film was comparable with the Reduction level usually obtainable by hydrazine. The sol–gel tungsten oxide film even showed an efficient Photocatalytic Reduction of the GO platelets after exposure to the visible light of the environment for 2 days.
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photodegradation of graphene oxide sheets by tio2 nanoparticles after a Photocatalytic Reduction
Journal of Physical Chemistry C, 2010Co-Authors: Omid Akhavan, Mohammad Abdolahad, Ali Esfandiar, M MohatashamifarAbstract:TiO2 nanoparticles were physically attached to chemically synthesized single-layer graphene oxide nanosheets deposited between Au electrodes in order to investigate the electrical, chemical, and structural properties of the TiO2/graphene oxide composition exposed to UV irradiation. X-ray photoelectron spectroscopy showed that after effective Photocatalytic Reduction of the graphene oxide sheets by the TiO2 nanoparticles in ethanol, the carbon content of the reduced graphene oxides gradually decreased by increasing the irradiation time, while no considerable variation was detected in the Reduction level of the reduced sheets. Raman spectroscopy indicated that, at first, the Photocatalytic Reduction resulted in a significant increase in the graphitized sp2 structure over the disorders in the graphene oxides. After that, as the carbon content decreased by UV irradiation, further disorders appeared in the reduced graphene oxide sheets, confirming degradation of the reduced sheets after the Photocatalytic redu...
Lucie Obalová - One of the best experts on this subject based on the ideXlab platform.
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Influence of reactor geometry on the yield of CO2 Photocatalytic Reduction
Catalysis Today, 2011Co-Authors: Kamila Kočí, Z. Lacný, Martin Reli, Ondřej Kozák, Daniela Plachá, Petr Praus, Lucie ObalováAbstract:The effect of reactor geometry on the Photocatalytic Reduction of CO2 employing ZnS-MMT (ZnS nanoparticles deposited on MMT) suspension was studied in two annular batch photoreactors. Reaction products in liquid phase (methanol) and in gas phase (methane, carbon monoxide, oxygen and hydrogen) were analyzed by GC/TCD/FID. The dependence of products yields on the reactor diameter and on the volume of the liquid phase confirmed the fact that the requirement of perfect mixing is difficult to fulfill in the annular configuration of the reactor. The highest yields of the Photocatalytic Reduction were achieved in a configuration where the lamp just touches the surface of the liquid in the reactor and the configuration of the reactor was not annular.
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Comparison of the pure TiO2 and kaolinite/TiO2 composite as catalyst for CO2 Photocatalytic Reduction
Catalysis Today, 2011Co-Authors: Kamila Kočí, Z. Lacný, Vlastimil Matějka, Pavel Kovář, Lucie ObalováAbstract:Abstract The kaolinite/TiO2 composite was prepared using thermal hydrolysis of kaolinite/titanyl sulphate suspension and characterized by XRFS, XRPD, SEM and N2 physical adsorption. Its Photocatalytic properties were evaluated by Photocatalytic Reduction of CO2 by water and compared with commercial TiO2 photocatalyst Degussa P25. Results showed that the yields of CO2 Photocatalytic Reduction products methane and methanol were higher over a kaolinite/TiO2 composite than over commercial TiO2 (Degussa P25) in spite of smaller proportion of TiO2 in the composite. Introducing of TiO2 nanoparticles into the kaolinite structure caused a decrease of anatase crystallite size. Kaolinite can also change acidobasic properties of catalyst surface, inhibit the recombination of electron–hole pairs and prevent the formation of TiO2 aggregates in suspension. These facts can contribute to the observed higher Photocatalytic efficiency of kaolinite/TiO2 compared to the commercial TiO2 photocatalyst.
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Wavelength Effect on Photocatalytic Reduction of CO2 by Ag/TiO2 Catalyst
Chinese Journal of Catalysis, 2011Co-Authors: K C, K. ZatloukalovÁ, A. HospodkovÁ, Z. Lacný, Sabina Krejčíková, Libor Čapek, Lucie Obalová, Olga SolcovaAbstract:Photocatalytic Reduction of CO2 by water was performed in the presence of a Ag/TiO2 catalyst under illumination by lamps with different wavelengths (254, 365, and 400 nm). The yields of the main products (methane and methanol) were higher with the 254 nm lamp than with the 365 lamp while no products were observed with the 400 nm lamp. This was because the electron-hole generation rate in- creased with increasing energy of irradiation (decreasing wavelength) and there were higher densities of electron states at higher energies in TiO2. The increased efficiency of electron-hole generation with a shorter wavelength irradiation increased the efficiency of the catalyst. The energy of the electrons excited by visible light (400 nm) was too low for CO2 Photocatalytic Reduction.
Jinlong Zhang - One of the best experts on this subject based on the ideXlab platform.
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Recent advances of doped graphite carbon nitride for Photocatalytic Reduction of CO 2 : a review
Research on Chemical Intermediates, 2020Co-Authors: Xiaoyue Huang, Da Liu, Ningkai Ding, Liang Zhou, Juying Lei, Lingzhi Wang, Jinlong ZhangAbstract:CO2 is the main gas that causes the “greenhouse effect,” and it is also a rich carbon resource. The Photocatalytic conversion of CO2 into fuel not only relieves the pressure brought by the environment pollution, but also is promising way to achieve the carbon cycle and address the problem of energy shortage. It is essential to design efficient photocatalysts for the practical application of Photocatalytic CO2 conversion. Doped graphite carbon nitride (g-C3N4) has a reduced bandgap, increased light absorption and effective charge separation and transfer efficiency. Recently, its application has been extended to the field of Photocatalytic Reduction of CO2. In this review, we first discuss the basic principles of Photocatalytic Reduction of CO2, then focus on the application of g-C3N4 doped with different elements in the Photocatalytic Reduction of CO2 in recent years, and then summarize different doping methods. Finally, challenges and opportunities are presented, and potential solutions are proposed for future research.
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size dependent activity and selectivity of carbon dioxide Photocatalytic Reduction over platinum nanoparticles
Nature Communications, 2018Co-Authors: Chunyang Dong, Cheng Lian, Songchang Hu, Zesheng Deng, Jianqiu Gong, Mingde Li, Mingyang Xing, Jinlong ZhangAbstract:Platinum nanoparticles (Pt NPs) are one of the most efficient cocatalysts in photocatalysis, and their size determines the activity and the selectivity of the catalytic reaction. Nevertheless, an in-depth understanding of the platinum’s size effect in the carbon dioxide Photocatalytic Reduction is still lacking. Through analyses of the geometric features and electronic properties with variable-sized Pt NPs, here we show a prominent size effect of Pt NPs in both the activity and selectivity of carbon dioxide Photocatalytic Reduction. Decreasing the size of Pt NPs promotes the charge transfer efficiency, and thus enhances both the carbon dioxide Photocatalytic Reduction and hydrogen evolution reaction (HER) activity, but leads to higher selectivity towards hydrogen over methane. Combining experimental results and theoretical calculations, in Pt NPs, the terrace sites are revealed as the active sites for methane generation; meanwhile, the low-coordinated sites are more favorable in the competing HER.
