Optimized the Carrier Transport Path and Separation Efficiency of 2D/2D Heterojunction in Photoelectrochemical Water Splitting
Hongxia Qian, Zhifeng Liu, Bo Zhang, Junwei Li, Jing Ya
Abstract
Abstract It is a promising strategy that the photoelectrode with high charge transfer rate and separation efficiency is designed in the photoelectrochemical (PEC) water splitting. Herein, the nanoflakes/nanoflakes (2D/2D) MoS 2 /ZnIn 2 S 4 heterojunction is synthesized by two‐step hydrothermal methods. The carrier transport path in heterojunction is optimized through the Schottky contact calculated by density functional theory (DFT) and large specific surface area between 2D nanoflakes MoS 2 and ZnIn 2 S 4 . Besides, the bimetallic oxyhydroxide NiFeOOH can be used as co‐catalyst to improve the separation of carriers. The results exhibit that MoS 2 /ZnIn 2 S 4 /NiFeOOH photoelectrode with dramatically enhanced photocurrent density of 0.74 mA/cm 2 at 1.23 V versus the reversible hydrogen electrode (V RHE ), which is 2.6 and 5.7 times higher than the bare MoS 2 and ZnIn 2 S 4 , respectively. And it has the largest charge separation efficiency (η bulk ) (22.8 %) and charge transfer efficiency (η surface ) (64.6 %) in the as‐prepared samples. This work provides a strategy for design of the photoelectrode with excellent charge transfer efficiency and separation efficiency in PEC water splitting.