Boosting the electrochemical CO2 reduction performance by Cu2O/β-Bi2O3 bimetallic heterojunction with the assistance of light

• Published in: Separation and purification technology 2024-02, Vol.330, p.125372, Article 125372
• Main Authors: Peng, Luwei, Lou, Wenshuang, Li, Lulu, Zhang, Yang, Luo, Xi, Xu, Nengneng, Qiao, Jinli
• Format: Article
• Language: English
• Subjects: Charge-transfer process; Co-electrodeposition method; Cu2O/β-Bi2O3; Micro-flower morphology; Photo-assisted electrochemical CO2 reduction
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2023.125372

[Display omitted] •Cu2O/β-Bi2O3 heterojunction has beautiful flower-like morphology.•The Cu2O and β-Bi2O3 phases in Cu-Bi-O/300 are independent.•The Cu2O/β-Bi2O3 heterojunction has excellent photo-assisted electrocatalytic CO2 reduction.•The Cu2O/β-Bi2O3 heterojunction can provide lots of active edge sites. CO2, as one of the greenhouse gases, actually represents a cheap and abundant C1 fuel to produce fuels and chemical stocks. Herein, inspired by photocatalysis and electrocatalysis, we have successfully synthesized a series of copper and bismuth oxides with heterostructure by a first co-electrodeposition method and then by thermal treatment at different temperatures. The bimetallic oxide (Cu2O/β-Bi2O3) at 300 °C with the main exposure of β-Bi2O3 (201) planes shows the beautiful micro-flower morphology with numerous petals in thickness around 20 ∼ 40 nm. Therefore, the Cu2O/β-Bi2O3 heterostructure with active edge sites can electrochemically convert CO2 into formate with a promising Faradaic efficiency (96.3 %) and current density (40.4 mA cm−2) at − 0.97 V vs. RHE. Specifically, the current density of Cu2O/β-Bi2O3 bimetallic catalyst can be largely enhanced to 48.5 mA cm−2 at − 0.92 V vs. RHE with the assistance of light compared to the 30.1 mA cm−2 without light. The production rate of formate with the assistance of light can also be increased to 705.1 μmol h−1 cm−2, superior to that of 536.4 μmol h−1 cm−2 without light. Such an excellent photo-assisted electrochemical CO2 reduction performance is due to the fast charge-transfer process between Cu2O and β-Bi2O3. This study may provide a new route to directly synthesize the photoactive electrocatalysts with more edge sites and heterojunction for promoting electrochemical CO2 reduction performance with the assistance of light field.