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

[Display omitted] •Conversion of N2 into ammonia is highly desirable for sustainable energy production.•The Au-WS2@RGO photoelectrode is more efficient at converting N2 to ammonia.•The detailed mechanism of PEC reduction of N2 to NH3 is investigated using DFT.•Au-WS2@RGO exhibits the highest NRR performance among state-of-the-art NRR catalysts. 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-1mgcat-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.