Development of a bi-compound heterogeneous cocatalyst modified p-Si photocathode for boosting the photoelectrochemical water splitting performance†

In this paper, a MoS2/Rh-P bi-compound heterogeneous cocatalyst is developed to improve the photoelectrochemical (PEC) water splitting performance of a p-Si photocathode. Compared with the single cocatalysts (MoS2 and Rh-P), the bi-compound heterogeneous cocatalyst MoS2/Rh-P on the p-Si photocathode surface exhibits a much better hydrogen evolution reaction (HER) activity at the electrode/electrolyte interface, which is attributed to the synergistic electronic effect between MoS2 and Rh-P materials. Meanwhile, the TiO2 layer could serve as a linker between p-Si and the surface cocatalyst to optimize the interface energy, further promoting the photocarrier transfer process within the system. Thus, the as-prepared p-Si-TiO2-MoS2/Rh-P photocathode exhibits excellent PEC performance with a high photocurrent density of -24.1 mA cm(-2) at 0 V (vs. RHE) and a positive onset potential of 0.43 V (vs. RHE). And the bi-compound heterogeneous cocatalyst provides a feasible strategy for boosting the PEC hydrogen evolution.

Automated summary

A MoS2/Rh-P bi-compound heterogeneous cocatalyst was developed to enhance the PEC water splitting performance of a p-Si photocathode, exhibiting improved hydrogen evolution activity and optimized interface energy via synergistic electronic effects. The TiO2 layer acted as a linker to promote photocarrier transfer process. The prepared p-Si-TiO2-MoS2/Rh-P photocathode demonstrated excellent PEC performance with high photocurrent density and positive onset potential, providing a feasible strategy for boosting PEC hydrogen evolution.