Au Nanocrystals Modified Holey PtTeAu Metallene Heteronanostructures for Plasmon‐Enhanced Nitrate Electroreduction

Abstract Ammonia (NH 3 ) is an essential chemical for agricultural production and a promising next‐generation hydrogen‐rich fuel. The electrocatalytic nitrate (NO 3 − ) reduction reaction (NO 3 RR) to NH 3 provides a sustainable and low‐energy method to replace industrial NH 3 synthesis. However, the NO 3 − to NH 3 conversion is limited by the complex eight‐electron and nine‐proton reduction processes, thus it is highly desirable to develop efficient electrocatalytic materials to overcome the kinetic barrier of NO 3 RR. Herein, Au nanocrystals (Au‐NCs) modified holey PtTeAu metallene (PtTeAu‐ML) heteronanostructures (Au‐NCs/PtTeAu‐MLs) are designed through phase and interface engineering, which achieve the high NH 3 yield (3.499 mg h −1 mg cat −1 ) and Faradaic efficiency of 96.3% for NO 3 RR at −0.03 V versus RHE. Detailed investigations reveal that the introduction of Te atoms significantly inhibits the high activity of Pt atoms for hydrogen evolution reaction that competes with NO 3 RR. Density functional theory results demonstrate that Au atoms further modulate the electronic structure of Pt in PtTe‐MLs, resulting in the upward shifted d band center of Pt and in turn the optimized NO 3 RR process on PtTeAu‐MLs. Furthermore, Au‐NCs allows the sustainable sunlight energy to accelerate the NO 3 RR kinetics at PtTeAu‐MLs because of the localized surface plasmon resonance of Au, inducing a higher NH 3 yield of 4.684 mg h −1 mg cat −1 under light irradiation condition.