Targeted removal of interfacial adventitious carbon towards directional charge delivery to isolated metal sites for efficient photocatalytic H2 production. (October 2020) - Li, Yunxiang
Abstract: Creation of clean interfaces without contamination of adventitious carbon and robust single active sites are highly desirable for delivery and utilization of electrons in sunlight-driven hydrogen production but still remains challenging in part owing to the lack of understanding in junction nature. Herein, we tackle this challenge by targeted removing of interfacial adventitious carbon between photoharvester CdS and novel single-cobalt co-catalyst (Co-NC). It's found that surface-trapped electrons can readily migrate to the closely attached Co-NC across the cleared interface between CdS and Co-NC. The small-resistance interfacial carrier path and the robust single-cobalt sites work in a cooperative way and hence achieve a superior visible-light driven H2 generation activity with a rate of 4.34 mmol/h, an apparent quantum yield (AQY) of 63.9% at 400 nm and a ultrahigh turnover frequency (TOF) of up to 16714.7 h −1 . Our finding will motivate future work in creating clean interfaces and unique single active sites for high performance photocatalysis. Graphical abstract: This study demonstrates a robust heterostructure constituting CdS, single-Co co-catalyst, and cleared interfaces removing adventitious carbon for visible-light-driven H2 generation. In this system, cleared interfaces and robust single-cobalt sites work cooperatively and hence achieve a H2 evolution rate of 4.34 mmol/h, an apparent quantum yield of 63.9% at 400 nm and a turnover frequency of up to 16714.7 h-1. Image 1 Highlights: The first clarification of cleared interface with less adventitious carbon. The cleared interface greatly promotes the electron transport across the junction. Isolated Co–N4 moiety delivers efficient co-catalytic H2 evolution performance. The cleared interface and single Co–N4 afford a superb photocatalytic activity.