Multi-strategies modulation for photocatalytic hydrogen evolution: Enhanced charge separation by coupling sulfur vacancies and built-in electric field at ohmic interface

Herein, via defect-induced phase engineering assisted by biomolecule of glucose, 2D MoS2 nanosheets with a hybrid 1T/2H phase (1T/2H-MS) are designed as cocatalyst to uniformly and vertically grown on the sulfur vacancy-riched ZnCdS (Vs-ZCS) to construct an ohmic contacted 1T/2H-MS@Vs-ZCS nano-junction. This meticulous design can improve light harvesting, promote charge separation and transportation, and realize remarkably efficient electron extraction. As revealed by serials of characterizations, it was the excellent co-catalytic property from hybrid MoS2 as well as the intensive built-in electric field at the ohmic junction that guarantee such exceptional charge kinetics in the 1T/2H-MS@Vs-ZCS system. Meanwhile, the rich sulfur vacancies can prolong carrier lifetimes and facilitate H* adsorption. As such, the photocatalytic H2 production performance of 1T/2H-MS@Vs-ZCS reaches 71.63 mmol·g−1·h−1 under visible light irradiation, which is 4.33 times superior to that of Vs-ZCS. The work provides a new strategy to design ideal atomic-scale heterointerface and high-efficiency photocatalyst through defect engineering for the photocatalytic water splitting reaction.