Creating an electron-rich region on ultrafine Bi2O3 nanoparticles to boost the electrochemical carbon dioxide reduction to formate

Abstract

Various metal–support composites have been reported for the electrochemical CO₂ reduction reaction (ECRR), while the effect of synergy between the size effect and interface regulation on ECRR performance is still rarely explored. Herein, we report ultrafine Bi₂O₃ nanoparticles (∼1.9 nm) decorated on a nitrogen-vacancy-rich graphitic carbon nitride (Bi₂O₃/NV-C₃N₄) electrocatalyst for highly efficient ECRR to formate. The Bi₂O₃/NV-C₃N₄ electrocatalyst can achieve 95% formate selectivity at −0.9 V vs. RHE and 24 h long-term stability. Moreover, substantial formate selectivity (>80%) was gained over a wide potential range of more than 700 mV. The excellent performance was attributed to the electron transfer from NVs to Bi₂O₃, forming an electron-rich region on Bi₂O₃ and accelerating the electron transfer from Bi₂O₃ to the adsorbed intermediates. This work provides a strategy for enhancing the catalytic activity of bismuth oxides to achieve a high efficiency for CO₂ reduction to generate liquid products.