Laser-Induced Co-Doped FePS₃ with Massively Phosphorus Sulfur Vacancies Nanosheet for Efficient and Highly Stable...

Purposely optimizing material structure to reduce the energy change of the rate-determining step (RDS) for promoting oxygen evolution reaction (OER) catalytic performance is a major strategy to enhance the energy efficiency of electrocatalytic water splitting. Density functional theory (DFT) simulations indicate that creating a large number of defects on or inside the 2D FePS₃ is very beneficial for its catalytic reaction of OER, especially when there are more defects, the structural diversity of the surface is more conducive to the adsorption and reaction of intermediates. In particular, when Co-doped FePS₃ surfaces produce a large number of S and P defects and expose metallic Fe as active sites, its catalytic performance, especially the catalytic stability, is significantly enhanced. A facile and efficient laser-ablation-in-liquid method is then designed to combine Co with 2D layered crystal FePS₃. Amazingly, the laser-induced (Fe_0.53Co_0.46)PS₃ sample exhibits excellent OER performance, with an overpotential at 288 mV and a small Tafel slope of 58.3 mV dec^-1. Moreover, (Fe_0.53Co_0.46)PS₃ operates stably for 138 h at 10 mA cm^-2 and 27 h at 100 mA cm^-2, which shows that the stability of (Fe_0.53Co_0.46)PS₃ far exceeds that of most of OER catalysts of Fe─Co system so far, and the comprehensive OER performance is in the first echelon of transition metal catalyst systems. This work proposes an in-depth understanding of the structural mechanism design of massive phosphorus sulfur vacancies by laser-induced manufacturing and will shed new light on promoting the stability of transition metal-based OER catalysts without any precious alternatives.