Constructing Co@TiO Nanoarray Heterostructure with Schottky Contact for Selective Electrocatalytic Nitrate Reduction to Ammonia.

Electrochemical nitrate (NO ) reduction reaction (NO RR) is a potential sustainable route for large-scale ambient ammonia (NH ) synthesis and regulating the nitrogen cycle. However, as this reaction involves multi-electron transfer steps, it urgently needs efficient electrocatalysts on promoting NH  selectivity. Herein, a rational design of Co nanoparticles anchored on TiO  nanobelt array on titanium plate (Co@TiO /TP) is presented as a high-efficiency electrocatalyst for NO RR. Density theory calculations demonstrate that the constructed Schottky heterostructures coupling metallic Co with semiconductor TiO  develop a built-in electric field, which can accelerate the rate determining step and facilitate NO adsorption, ensuring the selective conversion to NH . Expectantly, the Co@TiO /TP electrocatalyst attains an excellent Faradaic efficiency of 96.7% and a high NH  yield of 800.0 µmol h  cm  under neutral solution. More importantly, Co@TiO /TP heterostructure catalyst also presents a remarkable stability in 50-h electrolysis test.