Dynamical transfer behavior and in situ interaction with H2O molecules of charge carriers over heterojunction in non-adiabatic systems

Abstract

In adiabatic systems, both photocatalytic Z-scheme and S-scheme mechanisms are feasible. However, almost all photocatalysis are non-adiabatic, and the mechanisms need to be rationalized. Herein, CuS was in-situ grown at S locus of MoS2, thus increasing their wave function overlapping to decrease the interface barrier. In situ DRIFTS and XPS, and Hall effect studies have found that Fermi levels are not equal at interfaces in non-adiabatic system, and consequently the internal electric fields are formed at interfaces and localized electric fields in bulk and on surface, which boost e- and h+ to transfer directionally to MoS2 as reductive sites and CuS as oxidative sites for dehydrogenating * -OH and coupling * -O and releasing H2 and O2 with STH efficiency of 1.70%. In-depth insight into charge transfer behavior and dynamical reaction process over heterojunctions in non-adiabatic systems indicates the general validity of photocatalytic models and facilitates rational designs and photocatalysis principle understanding.