Extensive work on a Cu-modified TiO_(2) photocatalyst for CO_(2) reduction under visible light irradiation was conducted. The structure of the copper cocatalyst was established using UV-vis diff use refl ectance spect...Extensive work on a Cu-modified TiO_(2) photocatalyst for CO_(2) reduction under visible light irradiation was conducted. The structure of the copper cocatalyst was established using UV-vis diff use refl ectance spectroscopy, high-resolution transmis- sion electron microscopy, X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy. It was found that copper exists in different states (Cu 0 , Cu^(+) , and Cu^(2+) ), the content of which depends on the TiO_(2) calcination temperature and copper loading. The optimum composition of the cocatalyst has a photocatalyst based on TiO_(2) calcined at 700℃ and modified with 5 wt% copper, the activity of which is 22 μmol/(h·g cat ) (409 nm). Analysis of the photocatalysts after the photocatalytic reaction disclosed that the copper metal on the surface of the calcined TiO_(2) was gradually converted into Cu_(2) O during the photocatalytic reaction. Meanwhile, the metallic copper on the surface of the noncalcined TiO_(2) did not undergo any trans- formation during the reaction.展开更多
Volatile organic compounds (VOCs) are the major group of indoor air pollutants, which significantly impact indoor air quality (IAQ) and influence human health. Photocatalytic oxidation (PCO) is a cost-effective techno...Volatile organic compounds (VOCs) are the major group of indoor air pollutants, which significantly impact indoor air quality (IAQ) and influence human health. Photocatalytic oxidation (PCO) is a cost-effective technology for VOCs removal, compared with adsorption, biofiltration, or thermal catalysis method. Development of active photocatalyst systems is crucial for the PCO reaction. In this paper, the catalyst systems for photocatalysis under UV and visible light were discussed and the kinetics of photocatalytic oxidation was presented in order that some key influencing factors (relative huminity, light intensity, initial contaminant concentration and mass of catalyst) had also been studied. In addition, the future research directions were also presented in this paper.展开更多
The effect of the electron acceptors H2O2 and O2 on the type of generated reactive oxygen species（ROS）,and glycerol conversion and product distribution in the TiO2-catalyzed photocatalytic oxidation of glycerol was ...The effect of the electron acceptors H2O2 and O2 on the type of generated reactive oxygen species（ROS）,and glycerol conversion and product distribution in the TiO2-catalyzed photocatalytic oxidation of glycerol was studied at ambient conditions.In the absence of an electron acceptor,only HO^·radicals were generated by irradiated UV light and TiO2.However,in the presence of the two electron acceptors,both HO^· radical and ^1O2 were produced by irradiated UV light and TiO2 in different concentrations that depended on the concentration of the electron acceptor.The use of H2O2 as an electron acceptor enhanced glycerol conversion more than O2.The type of generated value-added compounds depended on the concentration of the generated ROS.展开更多
Black-colored titanium was obtained by anodic oxidation of a commercially pure grade-1 titanium sheet in a 0.06 M NH4NO3 solution, followed by heat treatment at 773 K for 1 h in a vacuum furnace. The resulting oxide l...Black-colored titanium was obtained by anodic oxidation of a commercially pure grade-1 titanium sheet in a 0.06 M NH4NO3 solution, followed by heat treatment at 773 K for 1 h in a vacuum furnace. The resulting oxide layer on the titanium substrate was examined by X-ray photoelectron spectroscopy, X-ray diffraction, glow discharge spectroscopy, and scanning electron microscopy. It was found that the oxide layer on the black-colored titanium sheet was several micrometers thick and mainly consisted of rutile TiO2 exhibiting a sponge like nanoporous structure. It is considered that the black-colored appearance of the titanium sheet is due to the sponge like nanoporous structure of the oxide layer absorbing the incident light. The photocatalytic activity of the black-colored titanium sheet was examined by observing the decomposition of a methylene blue (MB, C16H18N3SCl) solution under ultraviolet irradiation due to the existence of rutile TiO2. The sheet also exhibited photocatalytic activity under visible light irradiation. It is believed that the photocatalytic response upon irradiation with white light is due to carbon doping of the titanium oxide layer on the titanium substrate.展开更多
基金supported by Russian Science Foundation (No.#21-73-10235)
文摘Extensive work on a Cu-modified TiO_(2) photocatalyst for CO_(2) reduction under visible light irradiation was conducted. The structure of the copper cocatalyst was established using UV-vis diff use refl ectance spectroscopy, high-resolution transmis- sion electron microscopy, X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy. It was found that copper exists in different states (Cu 0 , Cu^(+) , and Cu^(2+) ), the content of which depends on the TiO_(2) calcination temperature and copper loading. The optimum composition of the cocatalyst has a photocatalyst based on TiO_(2) calcined at 700℃ and modified with 5 wt% copper, the activity of which is 22 μmol/(h·g cat ) (409 nm). Analysis of the photocatalysts after the photocatalytic reaction disclosed that the copper metal on the surface of the calcined TiO_(2) was gradually converted into Cu_(2) O during the photocatalytic reaction. Meanwhile, the metallic copper on the surface of the noncalcined TiO_(2) did not undergo any trans- formation during the reaction.
文摘Volatile organic compounds (VOCs) are the major group of indoor air pollutants, which significantly impact indoor air quality (IAQ) and influence human health. Photocatalytic oxidation (PCO) is a cost-effective technology for VOCs removal, compared with adsorption, biofiltration, or thermal catalysis method. Development of active photocatalyst systems is crucial for the PCO reaction. In this paper, the catalyst systems for photocatalysis under UV and visible light were discussed and the kinetics of photocatalytic oxidation was presented in order that some key influencing factors (relative huminity, light intensity, initial contaminant concentration and mass of catalyst) had also been studied. In addition, the future research directions were also presented in this paper.
基金Chulalongkorn University Dutsadi Phiphat Scholarshipthe Ratchadapisek Sompoch Endowment Fund(Sci-Super Ⅱ GF_58_08_23_01)the Thailand Research Fund(IRG5780001) for financial support
文摘The effect of the electron acceptors H2O2 and O2 on the type of generated reactive oxygen species（ROS）,and glycerol conversion and product distribution in the TiO2-catalyzed photocatalytic oxidation of glycerol was studied at ambient conditions.In the absence of an electron acceptor,only HO^·radicals were generated by irradiated UV light and TiO2.However,in the presence of the two electron acceptors,both HO^· radical and ^1O2 were produced by irradiated UV light and TiO2 in different concentrations that depended on the concentration of the electron acceptor.The use of H2O2 as an electron acceptor enhanced glycerol conversion more than O2.The type of generated value-added compounds depended on the concentration of the generated ROS.
文摘Black-colored titanium was obtained by anodic oxidation of a commercially pure grade-1 titanium sheet in a 0.06 M NH4NO3 solution, followed by heat treatment at 773 K for 1 h in a vacuum furnace. The resulting oxide layer on the titanium substrate was examined by X-ray photoelectron spectroscopy, X-ray diffraction, glow discharge spectroscopy, and scanning electron microscopy. It was found that the oxide layer on the black-colored titanium sheet was several micrometers thick and mainly consisted of rutile TiO2 exhibiting a sponge like nanoporous structure. It is considered that the black-colored appearance of the titanium sheet is due to the sponge like nanoporous structure of the oxide layer absorbing the incident light. The photocatalytic activity of the black-colored titanium sheet was examined by observing the decomposition of a methylene blue (MB, C16H18N3SCl) solution under ultraviolet irradiation due to the existence of rutile TiO2. The sheet also exhibited photocatalytic activity under visible light irradiation. It is believed that the photocatalytic response upon irradiation with white light is due to carbon doping of the titanium oxide layer on the titanium substrate.
