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

Ammonia (NH3) is an essential chemical for agricultural production and a promising next‐generation hydrogen‐rich fuel. The electrocatalytic nitrate (NO3−) reduction reaction (NO3RR) to NH3 provides a sustainable and low‐energy method to replace industrial NH3 synthesis. However, the NO3− to NH3 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 NO3RR. 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 NH3 yield (3.499 mg h−1 mgcat−1) and Faradaic efficiency of 96.3% for NO3RR 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 NO3RR. 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 NO3RR process on PtTeAu‐MLs. Furthermore, Au‐NCs allows the sustainable sunlight energy to accelerate the NO3RR kinetics at PtTeAu‐MLs because of the localized surface plasmon resonance of Au, inducing a higher NH3 yield of 4.684 mg h−1 mgcat−1 under light irradiation condition. [ABSTRACT FROM AUTHOR]