摘要
本论文通过两步水热法合成了MoS_2纳米片/CdS纳米线复合光催化剂.采用扫描电子显微镜、透射电子显微镜、X射线粉末衍射仪、拉曼光谱仪、X射线光电子能谱仪、比表面积分析仪、紫外可见漫反射光谱仪、荧光光谱方法和光电化学测试对复合光催化剂进行了表征.研究表明复合光催化剂的性能和MoS_2负载量的多少密切相关.当MoS_2的负载量为5 mol%时复合光催化剂具有最优的光学、光电化学和光催化产氢活性.与纯的CdS纳米线相比,优化后的复合光催化剂以葡萄糖和乳酸为空穴牺牲剂,光电流提高了5.5倍,光催化产氢活性提高了74倍,这主要归因于MoS_2纳米片和CdS纳米线之间的紧密接触有利于提高电荷的分离效率.为了进一步理解光电化学和光催化活性提高的机理,采用瞬态吸收光谱仪深入探究了电荷分离和转移的动力学过程.该工作不仅涉及了具有优良光电化学和光催化活性的复合光催化剂的制备方法,而且展示了葡萄糖在光解水产氢中的应用.
Nanocomposites composed of one-dimensional（1D） CdS nanowires（NWs） and 1 T-MoS2 nanosheets have been fabricated through a two-step solvothermal process. 5 mol% of MoS2 loading results in the best optical properties,photoelectrochemical（PEC） as well as photocatalytic activities for hydrogen evolution reaction（HER）. Compared with pure CdS NWs, the optimized nanocomposite shows 5.5 times enhancement in photocurrent and 86.3 times increase for HER in the presence of glucose and lactic acid as hole scavengers.The enhanced PEC and HER activities are attributed to the intimate contact between MoS2 and CdS that efficiently enhances charge carrier separation. In addition, ultrafast transient absorption（TA） measurements have been used to probe the charge carrier dynamics and gain deeper insight into the mechanism behind the enhanced PEC and photocatalytic performance.
基金
financially supported by the National Natural Science Foundation of China (51402126)
support from Delta Dental Health Associates, NASA through MACES (NNX15AQ01A)
UCSC Committee on Research Special Research Grant
