Modulation of the multiphase phosphorus/sulfide heterogeneous interface via rare earth for solar-enhanced water splitting at industrial-level current densities

Photoelectrically coupling water splitting at high current density is a promising approach for the acquisition of green hydrogen energy. However, it places significant demands on the photo/electrocatalysts. Herein, rare earth elements doping NiMoO₄-based phosphorus/sulfide heterostructure nanorod arrays (RE-NiMo-PS@NF [RE = Y, Er, La, and Sc]) are obtained for solar-enhanced electrocatalytic water splitting at high current densities. The results of the experiment and density-functional theory studies illustrate that the Y element as a dopant not only makes the NiMoP₂/NiMo₃S₄/NiMoO₄ heterostructure exhibit excellent solar-enhanced electrocatalytic activity (hydrogen evolution reaction [HER]: η₁₀₀₀ = 211 mV, oxygen evolution reaction [OER]: η₁₀₀₀ = 367 mV) but also optimizes the heterostructure interfacial electron density distributions and HER free energy. In addition, Y-NiMo-PS@NF achieves 18.64% solar-to-hydrogen efficiency. This study not only provides a new way to synthesize heterostructure electrocatalysts but also inspires the application of solar enhancement strategies for high current density water splitting.