Multivalent Sulfur Vacancy‐Rich NiCo2S4@MnO2 Urchin‐Like Heterostructures for Ambient Electrochemical N2 Reduction to NH3

Abstract Innovative advances in the exploitation of effective electrocatalytic materials for the reduction of nitrogen (N 2 ) to ammonia (NH 3 ) are highly required for the sustainable production of fertilizers and zero‐carbon emission fuel. In order to achieve zero‐carbon footprints and renewable NH 3 production, electrochemical N 2 reduction reaction (NRR) provides a favorable energy‐saving alternative but it requires more active, efficient, and selective catalysts. In current work, sulfur vacancy (Sv)‐rich NiCo 2 S 4 @MnO 2 heterostructures are efficaciously fabricated via a facile hydrothermal approach followed by heat treatment. The urchin‐like Sv‐NiCo 2 S 4 @MnO 2 heterostructures serve as cathodes, which demonstrate an optimal NH 3 yield of 57.31 µg h −1 mg cat −1 and Faradaic efficiency of 20.55% at −0.2 V versus reversible hydrogen electrode (RHE) in basic electrolyte owing to the synergistic interactions between Sv‐NiCo 2 S 4 and MnO 2 . Density functional theory (DFT) simulation further verifies that Co‐sites of urchin‐like Sv‐NiCo 2 S 4 @MnO 2 heterostructures are beneficial to lowering the energy threshold for N 2 adsorption and successive protonation. Distinctive micro/nano‐architectures exhibit high NRR electrocatalytic activities that might motivate researchers to explore and concentrate on the development of heterostructures for ambient electrocatalytic NH 3 generation.