Architecture Engineering and Phase Engineering of Rhodium Metallene Co‐Boost Nitrite‐to‐Ammonia Electroconversion

Abstract

AbstractElectrocatalytic nitrite reduction reaction (NO2RR) offers an effective strategy for sustainable ammonia (NH3) synthesis and N‐pollutants wastewater degradation. Herein, we propose a dual‐engineering strategy by combining architecture engineering and phase engineering on nanosheet‐like rhodium metallene (Rh‐NS) coupled with twisted nanoribbon‐like rhodium metallene (Rh‐NR) nanoarchitectonics (Rh‐NS/Rh‐NR) to boost NO2−‐to‐NH3 electroconversion. Rh‐NS/Rh‐NR, characterized by a high density of unsaturated coordination sites and a large specific surface area, greatly enhances the adsorption capacity of NO2− and crucial intermediates and lowers the energy barrier for the rate‐determining step of *NOH formation from *NO. Consequently, Rh‐NS/Rh‐NR exhibits satisfactory Faradaic efficiency (FE) of 98.7% and a remarkable NH3 yield rate of 44.3 mg mgcat−1 h−1 for NO2RR at high reduction potential (0.00 V). Using Rh‐NS/Rh‐NR as cathode, the assembled zinc–nitrite battery delivers excellent discharge performance (24.2 mW cm−2) and promising NH3 synthesis capacity (5.96 mg mgcat−1 h−1). This work not only guides the architecture‐engineering design of metallene but also demonstrates the practical potential of zinc–nitrite batteries in integrated energy‐environmental applications.