Bi<sub>2</sub>O<sub>3</sub>/BiO<sub>2</sub> Nanoheterojunction for Highly Efficient Electrocatalytic CO<sub>2</sub> Reduction to Formate
Xuezhen Feng, Haiyuan Zou, Renji Zheng, Wenfei Wei, Ranhao Wang, Wensong Zou, Gukhyun Lim, Jihyun Hong, Lele Duan, Hong Chen
Abstract
Heterostructure engineering plays a vital role in regulating the material interface, thus boosting the electron transportation pathway in advanced catalysis. Herein, a novel Bi2O3/BiO2 heterojunction catalyst was synthesized via a molten alkali-assisted dealumination strategy and exhibited rich structural dynamics for an electrocatalytic CO2 reduction reaction (ECO2RR). By coupling in situ X-ray diffraction and Raman spectroscopy measurements, we found that the as-synthesized Bi2O3/BiO2 heterostructure can be transformed into a novel Bi/BiO2 Mott–Schottky heterostructure, leading to enhanced adsorption performance for CO2 and *OCHO intermediates. Consequently, high selectivity toward formate larger than 95% was rendered in a wide potential window along with an optimum partial current density of −111.42 mA cm–2 that benchmarked with the state-of-the-art Bi-based ECO2RR catalysts. This work reports the construction and fruitful structural dynamic insights of a novel heterojunction electrocatalyst for ECO2RR, which paves the way for the rational design of efficient heterojunction electrocatalysts for ECO2RR and beyond.