Constructing S-scheme NiCo2O4/Zn2In2S5 heterojunction photocatalyst for boosted hydrogen evolution performance

Constructing S-scheme heterojunction photocatalyst is deemed as one of the effective strategy to enhance the photocatalytic hydrogen evolution performance of pristine semiconductor. In this study, a series of x% NiCo2O4/ Zn2In2S5 (NCO/ZIS5) S-scheme heterojunction photocatalysts were constructed by compositing bimetallic oxide NCO with ZIS5. The crystal phase, morphology, and chemical valence states of elements of the as-prepared samples were characterized employing XRD, SEM, TEM, XPS, etc. The results of photocatalytic hydrogen production experiment showed that the introduction of NCO significantly improved the photocatalytic performance of ZIS5, in which sample 2 % NCO/ZIS5 showed the best hydrogen production performance with a hydrogen rate of 15.45 mmol g-1h- 1. The improvement of hydrogen production performance of the composite photocatalyst can be attributed to the construction of S-scheme heterojunction, which promotes the separation and migration of charge carriers and the kinetics of hydrogen production. This study may provide a useful example for the construction of high hydrogen production S-scheme heterojunction photocatalysts using inexpensive and abundant bimetallic oxides.