Bio-inspired engineering of BiSPPy composite for the efficient electrocatalytic reduction of carbon dioxide

• Published in: Energy & environmental science Vol. 16; no. 9; pp. 3885 - 3898
• Main Authors: Li, Chengjin, Liu, Zhengzheng, Zhou, Xiaoxia, Zhang, Lifang, Fu, Zhengqian, Wu, Yiji, Lv, XiMeng, Zheng, Gengfeng, Chen, Hangrong
• Format: Journal Article
• Published: 13.09.2023
• DOI: 10.1039/d3ee02029k
• ISSN: 1754-5692

Using surface-engineered chemical composites to enhance the binding energy of reaction intermediates and the conductivity is an attractive route to achieve a high partial current density and increased yield of the target products. Herein, conductive polymer polypyrrole (PPy) was used to regulate the electronic structure of Bi 2 S 3 and facilitate the activation of CO 2 molecules to enhance the CO 2 electroreduction activity. The constructed electrocatalyst with a unique 3D hierarchical urchin-like nanoflower morphology was composed of Bi 2 S 3 nanowire assemblies with rich S vacancies via PPy modification, featuring an improved electron-transfer ability and outstanding formate faradaic efficiency of 91.18% and partial current density of 56.95 mA cm 2 , as well as good stability at a moderate potential in an H-type cell. More importantly, it could deliver current densities exceeding 300 mA cm 2 without compromising the selectivity of formate in a flow-cell reactor. A possible reaction mechanism for formate formation related to HCO 3 was proposed based on the in situ ATR-IR spectra, which could bring a new scientific understanding of CO 2 reduction. DFT calculations further demonstrated that the optimized electronic structure, boosted adsorption and activation of CO 2 , and protonation process contributed to a reduced formation energy for the formate intermediate *OCHO, leading to the enhanced performance. More impressively, ZnCO 2 batteries equipped with Bi 2 S 3 PPy displayed a maximum power density of 2.4 mW cm 2 and a superior cycle stability of >110 h. This study underlines the effectiveness of designing composite electrocatalysts to improve the CO 2 RR performance and thus provides a viable path toward carbon neutrality. Using surface-engineered chemical composites to enhance the binding energy of reaction intermediates and the conductivity is an attractive route to achieve a high partial current density and increased yield of the target products.