Discerning the mechanism of expedited interfacial electron transformation boosting photocatalytic hydrogen evolution by metallic 1T-WS2-induced photothermal effect

Modulation of electronic structure and facilitation of *H adsorption through defective sites is of great significance for photocatalytic hydrogen evolution. Here, we designed an S vacancies 1T-WS2/CdS to achieve 70.9 mmol/g/h hydrogen evolution rate accompanied with 39.1% AQY at 500 nm via coordinating the interfacial electronic engineering and photothermal effect. The photothermal effect induced by S vacancies 1T-WS2 effectively lowered the apparent activation energy from 15.96 kJ/mol to 10.51 kJ/mol, meanwhile, the directional migration of electrons from CdS to S vacancies accelerated by lattice heating was the main reason for boosting photocatalytic hydrogen evolution. Both the decrease of free energy of *H due to the existence of S vacancies and the enhancement of field strength caused by effective enrichment of electrons at the interface of S vacancies 1T-WS2/CdS. This work provided valuable insight into the use of non-precious metal co-catalysts for photo-thermal assisted photocatalytic hydrogen evolution.

Automated summary

Modulation of electronic structure and facilitation of *H adsorption through defective sites are important for photocatalytic hydrogen evolution. In this study, S vacancies 1T-WS2/CdS were designed to achieve high hydrogen evolution rate and AQY via coordinating interfacial electronic engineering and photothermal effect. The photothermal effect induced by S vacancies 1T-WS2 effectively lowers the apparent activation energy, and the directional migration of electrons from CdS to S vacancies accelerates photocatalytic hydrogen evolution.