Plate-on-plate structured MoS2/Cd0.6Zn0.4S Z-scheme heterostructure with enhanced photocatalytic hydrogen production activity via hole sacrificial agent synchronously strengthen half-reactions

Abstract

The practicable technology for producing hydrogen energy was mainly photocatalytic water splitting. Recently, heterostructural photocatalysts have attracted much attention due to its unique band structures and interfacial interactions. Herein, plate-on-plate MoS2/Cd0.6Zn0.4S heterostructure was rationally designed and fabricated by a simple strategy. It was revealed that Zn-doping content in the Cd0.6Zn0.4S solid solution as well as the mass ratio of MoS2 in the MoS2/Cd0.6Zn0.4S heterostructure can significantly affect the photocatalytic hydrogen evolution reaction (HER) activity. Especially, when Zn doping content is 40 % and the mass ratio of MoS2 is approximately 0.8 % (0.8 % MoS2/Cd0.6Zn0.4S), it exhibits the highest hydrogen production (47.68 µmol·g−1 at 2.5 h) without sacrificial agents. When Na2S/Na2SO3 is employed as sacrificial agent, its HER activity reaches 13466.50 µmol·g−1·h−1, 1.3 folds higher than Cd0.6Zn0.4S. The boosted HER activity of the Z-scheme MoS2/Cd0.6Zn0.4S heterostructure was ascribed to the greatly improved separation efficiency of photogenerated carriers. Most importantly, studies have revealed that the existence of sacrificial agents (Na2S/Na2SO3) can not only accelerate the kinetics of oxidation half reaction, but also synchronously strengthen HER half-reactions. The present work reveals a facile strategy for construction of Z-scheme heterostructures for efficient hydrogen evolution via hole sacrificial agent synchronously strengthen half-reactions.