To realize highly efficient hydrogen production of graphene-based photocatalysts,it is greatly important to increase more interfacial active sites onto graphene.In this work,the highly efficient CoS_(x)-rGO(reduced gr...To realize highly efficient hydrogen production of graphene-based photocatalysts,it is greatly important to increase more interfacial active sites onto graphene.In this work,the highly efficient CoS_(x)-rGO(reduced graphene oxide)/TiO_(2) composite photocatalyst was synthesized via a simple two-step method,including the hydrothermal loading of rGO nanosheets onto TiO_(2) nanoparticles and the subsequent photodeposition process of CoS_(x) nanodots(0.5-2 nm) on the rGO nanosheets.Photocatalytic experimental results confirmed that the CoS_(x)-rGO/TiO_(2) photocatalyst displayed a distinctly higher photocatalytic H_(2)-evolution activity than the TiO_(2) photocatalyst.The highest hydrogen-production efficiency of obtained CoS_(x)-rGO/TiO_(2)(10%) achieved 256.97 μmol·h-1,which was distinctly higher than that of TiO_(2)(4.41 μmol·h-1),rGO/TiO_(2)(20.19 μmol·h^(-1)) and CoS_(x)/TiO_(2)(132.67 μmol·h^(-1)).According to the results of various characterizations and tests,the synergistic-effect mechanism of CoS_(x) nanodots and rGO nanosheets is proposed to explain the increased photocatalytic performance of Co S_(x)-rGO/TiO_(2) photocatalytic material,namely the rGO nanosheets cause the quick transfer of photo-induced carriers from TiO_(2) to CoS_(x) nanodots,and then CoS_(x) nanodots work as hydrogenproduction active sites to quickly generate H_(2).The present study may offer innovative ideas for the preparation and application of new highly efficient and inexpensive photocatalytic materials.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.21771142 and 52073263)the Fundamental Research Funds for the Central Universities(No.WUT2019IB002)。
文摘To realize highly efficient hydrogen production of graphene-based photocatalysts,it is greatly important to increase more interfacial active sites onto graphene.In this work,the highly efficient CoS_(x)-rGO(reduced graphene oxide)/TiO_(2) composite photocatalyst was synthesized via a simple two-step method,including the hydrothermal loading of rGO nanosheets onto TiO_(2) nanoparticles and the subsequent photodeposition process of CoS_(x) nanodots(0.5-2 nm) on the rGO nanosheets.Photocatalytic experimental results confirmed that the CoS_(x)-rGO/TiO_(2) photocatalyst displayed a distinctly higher photocatalytic H_(2)-evolution activity than the TiO_(2) photocatalyst.The highest hydrogen-production efficiency of obtained CoS_(x)-rGO/TiO_(2)(10%) achieved 256.97 μmol·h-1,which was distinctly higher than that of TiO_(2)(4.41 μmol·h-1),rGO/TiO_(2)(20.19 μmol·h^(-1)) and CoS_(x)/TiO_(2)(132.67 μmol·h^(-1)).According to the results of various characterizations and tests,the synergistic-effect mechanism of CoS_(x) nanodots and rGO nanosheets is proposed to explain the increased photocatalytic performance of Co S_(x)-rGO/TiO_(2) photocatalytic material,namely the rGO nanosheets cause the quick transfer of photo-induced carriers from TiO_(2) to CoS_(x) nanodots,and then CoS_(x) nanodots work as hydrogenproduction active sites to quickly generate H_(2).The present study may offer innovative ideas for the preparation and application of new highly efficient and inexpensive photocatalytic materials.
