Structural Defects on Converted Bismuth Oxide Nanotubes Enable Highly Active Electrocatalysis of Carbon Dioxide Reduction
Qiufang Gong1,7, Pan Ding1,7, Mingquan Xu2,7, Xiaorong Zhu3,7, Maoyu Wang4,7, Jun Deng1, Qing Ma5, Na Han1, Yong Zhu2, Jun Lu6, Zhenxing Feng4, Yafei Li3, Wu Zhou2 & Yanguang Li1
1Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials and Devices, Soochow University, Suzhou 215123, China.
2School of Physical Sciences and CAS Key Laboratory of Vacuum Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
3College of Chemistry and Materials Science, Nanjing Normal University, Nanjing 210023, China.
4School of Chemical, Biological, and Environmental Engineering, Oregon State University, Corvallis, OR 97331, USA.
5DND-CAT, Synchrotron Research Center, Northwestern University, Evanston, IL 60208, USA.
6Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont IL60439, USA.
Formic acid (or formate) is suggested to be one of the most economically viable products from electrochemical carbon dioxide reduction. However, its commercial viability hinges on the development of highly active and selective electrocatalysts. Here we report that structural defects have a profound positive impact on the electrocatalytic performance of bismuth. Bismuth oxide double-walled nanotubes with fragmented surface are prepared as a template, and are cathodically converted to defective bismuth nanotubes. This converted electrocatalyst enables carbon dioxide reduction to formate with excellent activity, selectivity and stability. Most significantly, its current density reaches ~288 mA cm?2 at ?0.61 V versus reversible hydrogen electrode within a flow cell reactor under ambient conditions. Using density functional theory calculations, the excellent activity and selectivity are rationalized as the outcome of abundant defective bismuth sites that stabilize the *OCHO intermediate. Furthermore, this electrocatalyst is coupled with silicon photocathodes and achieves high performance photoelectrochemical carbon dioxide reduction.