Constructing Z-scheme heterojunction to improve the separation efficiency of photogenerated carriers of photocatalysts has gained extensive attention.In this work,we fabricated a novel Z-scheme MoO3/Bi2O4 heterojuncti...Constructing Z-scheme heterojunction to improve the separation efficiency of photogenerated carriers of photocatalysts has gained extensive attention.In this work,we fabricated a novel Z-scheme MoO3/Bi2O4 heterojunction photocatalyst by a hydrothermal method.XPS analysis results indicated that strong interaction between MoO3 and Bi2O4 is generated,which contributes to charge transfer and separation of the photogenerated carriers.This was confirmed by photoluminescence(PL)and electrochemical impedance spectroscopy(EIS)tests.The photocatalytic performance of the as-synthesized photocatalysts was evaluated by degrading rhodamine B(RhB)in aqueous solution under visible light irradiation,showing that 15%MoO3/Bi2O4(15-MB)composite exhibited the highest photocatalytic activity,which is 2 times higher than that of Bi2O4.Besides,the heterojunction photocatalyst can keep good photocatalytic activity and stability after five recycles.Trapping experiments demonstrated that the dominant active radicals in photocatalytic reactions are superoxide radical( O2-)and holes(h+),indicating that the 15-MB composite is a Z-scheme photocatalyst.Finally,the mechanism of the Z-scheme MoO3/Bi2O4 composite for photo-degrading RhB in aqueous solution is proposed.This work provides a promising strategy for designing Bi-based Z-scheme heterojunction photocatalysts for highly efficient removal of environmental pollutants.展开更多
CeOsupports were prepared by calcination or precipitation method and 5% MoO/CeOcatalysts were prepared by incipient-wetness impregnation method. The catalytic performance of the 5% MoO/CeOcatalysts toward sulfur-resis...CeOsupports were prepared by calcination or precipitation method and 5% MoO/CeOcatalysts were prepared by incipient-wetness impregnation method. The catalytic performance of the 5% MoO/CeOcatalysts toward sulfur-resistant methanation was investigated. The results showed that the Mo/Ce-1 catalysts with CeOsupport prepared by calcination method exhibited the best sulfur-resistant methanation activity and stability with CO conversion as high as 75% while the Mo/Ce-3 catalysts the poorest. The supports and catalysts were characterized by N-adsorption–desorption, temperature-programmed reduction（TPR）, X-ray diffraction（XRD）, Raman spectroscopy（RS） and scanning electron microscope（SEM）. The results indicated that the saturated monolayer loading MoOon Ce-3 support was lower than 5% and there were some crystalline MoOparticles on the surface of the Mo/Ce-3. The preparation method of CeOhad a big influence on the specific surface area, the crystalline of CeO, and the catalytic performance of the corresponding Mo-based catalyst for sulfur-resistant methanation.展开更多
MoO3/MCM-49 has been synthesized under the special condition and it shows a high activity and selectivity for nonoxidative aromatization of methane with a long lifetime and extreme capacity of anti-coking. MoO3/MCM-49...MoO3/MCM-49 has been synthesized under the special condition and it shows a high activity and selectivity for nonoxidative aromatization of methane with a long lifetime and extreme capacity of anti-coking. MoO3/MCM-49 is considered as a very promising catalyst for the title reaction.展开更多
基金supported by the Natural Science Foundation of Hubei Province(2016CFA078)the National Natural Science Foundation of China(51472194)~~
文摘Constructing Z-scheme heterojunction to improve the separation efficiency of photogenerated carriers of photocatalysts has gained extensive attention.In this work,we fabricated a novel Z-scheme MoO3/Bi2O4 heterojunction photocatalyst by a hydrothermal method.XPS analysis results indicated that strong interaction between MoO3 and Bi2O4 is generated,which contributes to charge transfer and separation of the photogenerated carriers.This was confirmed by photoluminescence(PL)and electrochemical impedance spectroscopy(EIS)tests.The photocatalytic performance of the as-synthesized photocatalysts was evaluated by degrading rhodamine B(RhB)in aqueous solution under visible light irradiation,showing that 15%MoO3/Bi2O4(15-MB)composite exhibited the highest photocatalytic activity,which is 2 times higher than that of Bi2O4.Besides,the heterojunction photocatalyst can keep good photocatalytic activity and stability after five recycles.Trapping experiments demonstrated that the dominant active radicals in photocatalytic reactions are superoxide radical( O2-)and holes(h+),indicating that the 15-MB composite is a Z-scheme photocatalyst.Finally,the mechanism of the Z-scheme MoO3/Bi2O4 composite for photo-degrading RhB in aqueous solution is proposed.This work provides a promising strategy for designing Bi-based Z-scheme heterojunction photocatalysts for highly efficient removal of environmental pollutants.
基金Financial supports from the National High Technology Research and Development Program of China(863 Project)(2015AA050504)the National Natural Science Foundation of China(21576203)
文摘CeOsupports were prepared by calcination or precipitation method and 5% MoO/CeOcatalysts were prepared by incipient-wetness impregnation method. The catalytic performance of the 5% MoO/CeOcatalysts toward sulfur-resistant methanation was investigated. The results showed that the Mo/Ce-1 catalysts with CeOsupport prepared by calcination method exhibited the best sulfur-resistant methanation activity and stability with CO conversion as high as 75% while the Mo/Ce-3 catalysts the poorest. The supports and catalysts were characterized by N-adsorption–desorption, temperature-programmed reduction（TPR）, X-ray diffraction（XRD）, Raman spectroscopy（RS） and scanning electron microscope（SEM）. The results indicated that the saturated monolayer loading MoOon Ce-3 support was lower than 5% and there were some crystalline MoOparticles on the surface of the Mo/Ce-3. The preparation method of CeOhad a big influence on the specific surface area, the crystalline of CeO, and the catalytic performance of the corresponding Mo-based catalyst for sulfur-resistant methanation.
文摘MoO3/MCM-49 has been synthesized under the special condition and it shows a high activity and selectivity for nonoxidative aromatization of methane with a long lifetime and extreme capacity of anti-coking. MoO3/MCM-49 is considered as a very promising catalyst for the title reaction.
