Bi₂O₃/BiO₂ Nanoheterojunction\nfor Highly Efficient Electrocatalytic CO₂ Reduction to\nFormate

Abstract

Heterostructure\nengineering plays a vital role in regulating the\nmaterial interface, thus boosting the electron transportation pathway\nin advanced catalysis. Herein, a novel Bi₂O₃/BiO₂ heterojunction catalyst was synthesized via a molten\nalkali-assisted dealumination strategy and exhibited rich structural\ndynamics for an electrocatalytic CO₂ reduction reaction\n(ECO₂RR). By coupling in situ X-ray diffraction and Raman\nspectroscopy measurements, we found that the as-synthesized Bi₂O₃/BiO₂ heterostructure can be transformed\ninto a novel Bi/BiO₂ Mott–Schottky heterostructure,\nleading to enhanced adsorption performance for CO₂ and\n*OCHO intermediates. Consequently, high selectivity toward formate\nlarger than 95% was rendered in a wide potential window along with\nan 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\ndynamic insights of a novel heterojunction electrocatalyst for ECO₂RR, which paves the way for the rational design of efficient\nheterojunction electrocatalysts for ECO₂RR and beyond.