Plasmonic Au nanoparticles anchored 2D WS₂@RGO for high-performance photoelectrochemical nitrogen reduction to ammonia

The photoelectrochemical reduction of nitrogen to ammonia (NH₃) is a sustainable and cost-effective process. The photoelectrocatalysts adsorb light, activate N₂, and transport electrons efficiently to achieve high-yield NH₃. In the present work, gold-tungsten sulfide-anchored reduced graphene oxides (Au-WS₂@RGO) are developed as highly efficient photoelectrocatalysts for the N₂ reduction reaction (NRR) to synthesize NH₃. The effect of Au nanoparticles loaded on WS₂@RGO is optimized to achieve hierarchical 2D Au-WS₂@RGO with excellent electrical conductivity, large active surface area, and unique porous network. Photoelectrocatalytic NRR of Au-WS₂@RGO achieves remarkable NH₃ production rates with ultrahigh NH₃ yield of 34 μgh^-1mg_cat^-1 at −0.6 V, tremendous faradaic efficiency (FE) of 16.2 %, long durability for about 14 h, and prolonged lifetime of photo-carriers. DFT calculations support the experimental findings and demonstrate that Au-WS₂@RGO as an effeient NRR catalyst with low overpotential. The Au-WS₂@RGO shows the highest NRR performances even in atmospheric air (AirRR) and outperforms the state-of-the-art NRR catalysts. The high AirRR performance and durability of Au-WS₂@RGO make it a promising alternative to Au-based NRR catalysts in photo electrolyzers. Further, an innovative methodology will be proposed for high-efficiency urea fertilizer production using Au-WS₂@RGO-based NRR photocatalysts.