Combined CdS/In2S3 heterostructures with cocatalyst for boosting carriers separation and photoelectrochemical water splitting

Abstract CdS with a nature of serious photocorrosion and poor photogenerated electron-hole pairs separation defects would restrict its further development. Herein, we reported that In2S3 and the cocatalyst NiOOH were modified CdS by successive ionic layer adsorption and reaction (SILAR) and photoassisted electrodeposition method. In this ternary system, the type-II heterojunction constructed by CdS and highly dispersed In2S3 (silar 15 cycles) to greatly improve the efficiency of photogenerated carrier separation, while NiOOH could avoid direct contact between CdS/In2S3 and electrolyte to protect it from photocorrosion. Concretely, the CdS/15In2S3 showed the photogenerated carrier injection efficiency (ηinj) and surface carrier separation efficiency (ηsep) achieved 18.4% and 24.6% at 1.23 V vs. RHE, respectively. The CdS/15In2S3/NiOOH (C/15I/N) demonstrated the photostability decreased only by 30.7% under 1 h illumination. This work reveals a feasible measure for sustainable and effective photoelectrochemical (PEC) water splitting via fabricating heterojunction with highly dispersed materials on CdS-based surface.