Hierarchically nanostructured, porous TiO_2(B) microspheres were synthesized by a microwave-assisted solvothermal method combined with subsequent heat treatment in air. The materials were carefully characterized by sc...Hierarchically nanostructured, porous TiO_2(B) microspheres were synthesized by a microwave-assisted solvothermal method combined with subsequent heat treatment in air. The materials were carefully characterized by scanning and transmission electron microscopy, X-ray diffraction, CO_2 adsorption, and a range of spectroscopies, including Raman, infrared, X-ray photoelectron and UV-Vis spectroscopy. The hierarchical TiO_2(B) particles are constructed by ultrathin nanosheets and possess large specific surface area, which provided many active sites for CO_2 adsorption as well as CO_2 conversion. The TiO_2(B)nanostructures exhibited marked photocatalytic activity for CO_2 reduction to methane and methanol. Anatase TiO_2 and P25 were used as the reference photocatalysts. Transient photocurrent measurement also proved the higher photoactivity of TiO_2(B) than that of anatase TiO_2. In-situ infrared spectrum was measured to identify the intermediates and deduce the conversion process of CO_2 under illumination over TiO_2(B) photocatalyst.展开更多
Photocatalytic Hproduction from water splitting has a promising prospect for alleviating energy and environmental issues.However,the fast recombination of photogenerated charge carriers limits the photocatalytic effic...Photocatalytic Hproduction from water splitting has a promising prospect for alleviating energy and environmental issues.However,the fast recombination of photogenerated charge carriers limits the photocatalytic efficiency and its practical application.Cocatalyst engineering is an effective strategy to spatially separate photogenerated charge carriers.In this work,noble-metal-free MoSand CoOcocatalysts are loaded on CdS nanorods by a two-step photodeposition method.The MoSfunctions as the reduction cocatalyst to trap electrons and Co Oas the oxidation cocatalyst to trap holes.Transmission electron microscopy(TEM),inductively coupled plasma(ICP),X-ray photoelectron spectroscopy(XPS)and MottSchottky results demonstrate the effectiveness of photodeposition for loading MoSand CoOdual cocatalysts on CdS and their impact on the photochemical properties.The optimized CdS-MoS-CoOcomposite exhibits a high photocatalytic H-production rate of 7.4 mmol g^(-1)h^(-1)and an apparent quantum efficiency(QE)of 7.6%at 420 nm.Further analysis on time-resolved photoluminescence(TRPL)indicates that the introduction of dual cocatalysts greatly prolongs the lifetime of photogenerated charge carriers and deceases the charge recombination rates,consequently leading to superior photocatalytic H-production performance.This work provides a facile and effective strategy for the construction of highly efficient dual-cocatalyst-modified CdS photocatalyst for high-performance photocatalytic Hproduction.展开更多
A novel cocatalyst,i.e.metallic nickel nanoparticles encapsulated in few-layer graphene(Ni@C),is obtained by carbonization of metal–organic frameworks(MOF)and leaching treatment of hydrochloric acid.It is selected as...A novel cocatalyst,i.e.metallic nickel nanoparticles encapsulated in few-layer graphene(Ni@C),is obtained by carbonization of metal–organic frameworks(MOF)and leaching treatment of hydrochloric acid.It is selected as the cocatalyst for CdS nanosheets,forming CdS-Ni@C nanocomposites.It remarkably improves the photocatalytic activities of CdS nanosheets due to the synergistic effect of Ni nanoparticles and graphene layers.In addition,the Ni nanoparticles encapsulated by graphene layers effectively isolate Ni from the ambient,which avoids contamination and curbs corrosion.The larger work function of Ni@C and outstanding conductivity of graphene promote the electron transfer from CdS to Ni@C,suppressing the recombination of photogenerated carriers and facilitating the separation of photogenerated electronhole pairs.This strategy by adopting this novel cocatalyst provides a new solution to the improvement of the photocatalytic hydrogen production.展开更多
基金supported by the National Basic Research Program of China(2013CB632402)the National Natural Science Foundation of China(51320105001,21433007,51372190,21573170)+3 种基金the Natural Science Foundation of Hubei Province(2015CFA001)the Fundamental Research Funds for the Central Universities(WUT:2015-III-034)Innovative Research Funds of SKLWUT(2017-ZD-4)the Discovery Early Career Researcher Award(DECRA)by Australian Research Council(DE160101488)
文摘Hierarchically nanostructured, porous TiO_2(B) microspheres were synthesized by a microwave-assisted solvothermal method combined with subsequent heat treatment in air. The materials were carefully characterized by scanning and transmission electron microscopy, X-ray diffraction, CO_2 adsorption, and a range of spectroscopies, including Raman, infrared, X-ray photoelectron and UV-Vis spectroscopy. The hierarchical TiO_2(B) particles are constructed by ultrathin nanosheets and possess large specific surface area, which provided many active sites for CO_2 adsorption as well as CO_2 conversion. The TiO_2(B)nanostructures exhibited marked photocatalytic activity for CO_2 reduction to methane and methanol. Anatase TiO_2 and P25 were used as the reference photocatalysts. Transient photocurrent measurement also proved the higher photoactivity of TiO_2(B) than that of anatase TiO_2. In-situ infrared spectrum was measured to identify the intermediates and deduce the conversion process of CO_2 under illumination over TiO_2(B) photocatalyst.
基金the National Science Foundation of China(Nos.22005228 and 52063028)。
文摘Photocatalytic Hproduction from water splitting has a promising prospect for alleviating energy and environmental issues.However,the fast recombination of photogenerated charge carriers limits the photocatalytic efficiency and its practical application.Cocatalyst engineering is an effective strategy to spatially separate photogenerated charge carriers.In this work,noble-metal-free MoSand CoOcocatalysts are loaded on CdS nanorods by a two-step photodeposition method.The MoSfunctions as the reduction cocatalyst to trap electrons and Co Oas the oxidation cocatalyst to trap holes.Transmission electron microscopy(TEM),inductively coupled plasma(ICP),X-ray photoelectron spectroscopy(XPS)and MottSchottky results demonstrate the effectiveness of photodeposition for loading MoSand CoOdual cocatalysts on CdS and their impact on the photochemical properties.The optimized CdS-MoS-CoOcomposite exhibits a high photocatalytic H-production rate of 7.4 mmol g^(-1)h^(-1)and an apparent quantum efficiency(QE)of 7.6%at 420 nm.Further analysis on time-resolved photoluminescence(TRPL)indicates that the introduction of dual cocatalysts greatly prolongs the lifetime of photogenerated charge carriers and deceases the charge recombination rates,consequently leading to superior photocatalytic H-production performance.This work provides a facile and effective strategy for the construction of highly efficient dual-cocatalyst-modified CdS photocatalyst for high-performance photocatalytic Hproduction.
基金Financially supported by the National Key Research and Development Program of China(No.2018YFB1502001)the National Natural Science Foundation of China(Nos.51872220,21871217,51961135303,51932007,U1905215 and U1705251)。
文摘A novel cocatalyst,i.e.metallic nickel nanoparticles encapsulated in few-layer graphene(Ni@C),is obtained by carbonization of metal–organic frameworks(MOF)and leaching treatment of hydrochloric acid.It is selected as the cocatalyst for CdS nanosheets,forming CdS-Ni@C nanocomposites.It remarkably improves the photocatalytic activities of CdS nanosheets due to the synergistic effect of Ni nanoparticles and graphene layers.In addition,the Ni nanoparticles encapsulated by graphene layers effectively isolate Ni from the ambient,which avoids contamination and curbs corrosion.The larger work function of Ni@C and outstanding conductivity of graphene promote the electron transfer from CdS to Ni@C,suppressing the recombination of photogenerated carriers and facilitating the separation of photogenerated electronhole pairs.This strategy by adopting this novel cocatalyst provides a new solution to the improvement of the photocatalytic hydrogen production.
