摘要
Photocatalytic hydrogen production by overall water solar-splitting is a prospective strategy to solve energy crisis.However,the rapid recombination of photogenerated electron–hole pairs deeply restricts photocatalytic activity of catalysts.Here,the in-situ transient photovoltage(TPV)technique was developed to investigate the interfacial photogenerated carrier extraction,photogenerated carrier recombination and the interfacial electron delivery kinetics of the photocatalyst.The carbon dots/NiCo_(2)O_(4)(CDs/NiCo_(2)O_(4))composite shows weakened recombination rate of photogenerated carriers due to charge storage of CDs,which enhances the photocatalytic water decomposition activity without any scavenger.CDs can accelerate the interface electron extraction about 0.09 ms,while the maximum electron storage time by CDs is up to 0.7 ms.The optimal CDs/NiCo_(2)O_(4)composite(5 wt.%CDs)displays the hydrogen production of 62µmol·h^(−1)·g^(−1) and oxygen production of 29µmol·h^(−1)·g^(−1) at normal atmosphere,which is about 4 times greater than that of pristine NiCo_(2)O_(4).This work provides sufficient evidence on the charge storage of CDs and the interfacial charge kinetics of photocatalysts on the basis of in-situ TPV tests.
基金
the National Key Research and Development Program of China(Nos.2020YFA0406104,2020YFA0406101,and 2020YFA0406103)
the National MCF Energy R&D Program(No.2018YFE0306105)
Innovative Research Group Project of the National Natural Science Foundation of China(No.51821002)
the National Natural Science Foundation of China(Nos.51725204,21771132,51972216,and 52041202)
Natural Science Foundation of Jiangsu Province(No.BK20190041)
Key-Area Research and Development Program of Guangdong Province(No.2019B010933001)
Collaborative Innovation Center of Suzhou Nano Science&Technology,and the 111 Project.
