Rational Construction of Heterostructured Cu₃P@TiO₂ Nanoarray for High‐Efficiency Electrochemical Nitrite Reduction to Ammonia

Electroreduction of nitrite (NO 2 − ) to valuable ammonia (NH 3 ) offers a sustainable and green approach for NH 3 synthesis. Here, a Cu 3 P@TiO 2 heterostructure is rationally constructed as an active catalyst for selective NO 2 − ‐to‐NH 3 electroreduction, with rich nanosized Cu 3 P anchored on a TiO 2 nanoribbon array on Ti plate (Cu 3 P@TiO 2 /TP). When performed in the 0.1 m NaOH with 0.1 m NaNO 2 , the Cu 3 P@TiO 2 /TP electrode obtains a large NH 3 yield of 1583.4 µmol h −1 cm −2 and a high Faradaic efficiency of 97.1%. More importantly, Cu 3 P@TiO 2 /TP also delivers remarkable long‐term stability for 50 h electrolysis. Theoretical calculations indicate that intermediate adsorption/conversion processes on Cu 3 P@TiO 2 interfaces are synergistically optimized, substantially facilitating the conversion of NO 2 − ‐to‐NH 3 .