TiO2/WS2/g-C3N4composite photocatalysts were synthesized by a liquid-exfoliation-solvothermal method.In this process,the WS2/g-C3N4nano-sheets were prepared by liquid-exfoliation method from the bulk WS2and C3N4in the...TiO2/WS2/g-C3N4composite photocatalysts were synthesized by a liquid-exfoliation-solvothermal method.In this process,the WS2/g-C3N4nano-sheets were prepared by liquid-exfoliation method from the bulk WS2and C3N4in the alcohol system,and then the TiO2nanoparticles(NPs)grew on the WS2/g-C3N4nano-sheets by in-situ synthesized technique.The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic degradation of methyl orange(MO).The results showed that the as-prepared samples exhibited higher photocatalytic activities as compared to the pure TiO2,g-C3N4and TiO2/g-C3N4composite.The enhanced photocatalytic activities of TiO2/WS2/g-C3N4photocatalysts could be attributed to the synergistic effect of heterostructure between TiO2NPs and WS2/g-C3N4nano-sheets,which could efficiently improve the separation of photogenerated electron/hole pairs and utilization efficiency of photons.The quenching tests of radicals indicated that?O2?had crucial effect on degradation of MO,which demonstrated that?O2?was the main active radical in photocatalytic reaction process.展开更多
Semiconductor oxides are widely used to achieve photocatalytic removal of NOx(NO and NO2) species. These materials also exhibit enhanced oxidation ability in thermally assisted photocatalysis;however, many of them ten...Semiconductor oxides are widely used to achieve photocatalytic removal of NOx(NO and NO2) species. These materials also exhibit enhanced oxidation ability in thermally assisted photocatalysis;however, many of them tend to be deactivated at high relative humidity(RH) levels. In the case of the benchmark P25 TiO2 photocatalyst, we observe a significant decrease in non-NO2 selectivity from 95.02% to 58.33% when RH increases from 20% to 80%. Interestingly, the porous TiO2(B) microspheres synthesized in this work exhibit 99% selectivity at 20% RH;the selectivity remains as high as 96.18% at 80% RH. The high humidity tolerance of the TiO2(B) sample can be ascribed to its strong water desorption capacity and easy O2 adsorption at elevated temperatures, which reflects the fact that the superoxide radical is the main active species for the deep oxidation of NOx. This work may inspire the design of efficient photothermal catalysts with application in NOx removal in hot and humid environments.展开更多
基金Projects(21376099,21546002)supported by the National Natural Science Foundation of China
文摘TiO2/WS2/g-C3N4composite photocatalysts were synthesized by a liquid-exfoliation-solvothermal method.In this process,the WS2/g-C3N4nano-sheets were prepared by liquid-exfoliation method from the bulk WS2and C3N4in the alcohol system,and then the TiO2nanoparticles(NPs)grew on the WS2/g-C3N4nano-sheets by in-situ synthesized technique.The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic degradation of methyl orange(MO).The results showed that the as-prepared samples exhibited higher photocatalytic activities as compared to the pure TiO2,g-C3N4and TiO2/g-C3N4composite.The enhanced photocatalytic activities of TiO2/WS2/g-C3N4photocatalysts could be attributed to the synergistic effect of heterostructure between TiO2NPs and WS2/g-C3N4nano-sheets,which could efficiently improve the separation of photogenerated electron/hole pairs and utilization efficiency of photons.The quenching tests of radicals indicated that?O2?had crucial effect on degradation of MO,which demonstrated that?O2?was the main active radical in photocatalytic reaction process.
文摘Semiconductor oxides are widely used to achieve photocatalytic removal of NOx(NO and NO2) species. These materials also exhibit enhanced oxidation ability in thermally assisted photocatalysis;however, many of them tend to be deactivated at high relative humidity(RH) levels. In the case of the benchmark P25 TiO2 photocatalyst, we observe a significant decrease in non-NO2 selectivity from 95.02% to 58.33% when RH increases from 20% to 80%. Interestingly, the porous TiO2(B) microspheres synthesized in this work exhibit 99% selectivity at 20% RH;the selectivity remains as high as 96.18% at 80% RH. The high humidity tolerance of the TiO2(B) sample can be ascribed to its strong water desorption capacity and easy O2 adsorption at elevated temperatures, which reflects the fact that the superoxide radical is the main active species for the deep oxidation of NOx. This work may inspire the design of efficient photothermal catalysts with application in NOx removal in hot and humid environments.
