Constructing Co@TiO<sub>2</sub> Nanoarray Heterostructure with Schottky Contact for Selective Electrocatalytic Nitrate Reduction to Ammonia
Xiaoya Fan, Donglin Zhao, Zhiqin Deng, Longcheng Zhang, Jun Li, Zerong Li, Shengjun Sun, Yongsong Luo, Dongdong Zheng, Yan Wang, Binwu Ying, Jing Zhang, Abdulmohsen Ali Alshehri, Yuxiao Lin, Chengwu Tang, Xuping Sun, Yinyuan Zheng
Abstract
Abstract Electrochemical nitrate (NO 3 − ) reduction reaction (NO 3 − RR) is a potential sustainable route for large‐scale ambient ammonia (NH 3 ) synthesis and regulating the nitrogen cycle. However, as this reaction involves multi‐electron transfer steps, it urgently needs efficient electrocatalysts on promoting NH 3 selectivity. Herein, a rational design of Co nanoparticles anchored on TiO 2 nanobelt array on titanium plate (Co@TiO 2 /TP) is presented as a high‐efficiency electrocatalyst for NO 3 − RR. Density theory calculations demonstrate that the constructed Schottky heterostructures coupling metallic Co with semiconductor TiO 2 develop a built‐in electric field, which can accelerate the rate determining step and facilitate NO 3 − adsorption, ensuring the selective conversion to NH 3 . Expectantly, the Co@TiO 2 /TP electrocatalyst attains an excellent Faradaic efficiency of 96.7% and a high NH 3 yield of 800.0 µmol h −1 cm −2 under neutral solution. More importantly, Co@TiO 2 /TP heterostructure catalyst also presents a remarkable stability in 50‐h electrolysis test.