A high H2 evolution rate under visible light of a CdS/TiO2@NiS catalyst due to a directional electron transfer between the phases

The photocatalytic activity of CdS can be greatly improved by co-modification of NiS and TiO2 materials; furthermore the order of connection affects much. A directional electron transfer route via CdS -> TiO2 -> NiS is found crucial to the enhancement of ternary catalyst, where TiO2 acts as an electron reservoir and NiS works as an effective cocatalyst. CdS/TiO2@NiS with NiS loaded on TiO2 has an activity of H-2 evolution 2.5 times higher than NiS@CdS/TiO2 with NiS pre-loaded on CdS. Faster e(-)/h(+) separation rates is obtained of CdS/TiO2@NiS under visible light than under extra UV light irradiation, which in turn demonstrates the importance of directional electron transfer route. (C) 2018 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd.. All rights reserved.