Nanostructured Au Electrode with 100 h Stability for Solar-Driven Electrochemical Reduction of Carbon Dioxide to Carbon Monoxide

Hyojung Bae; Chaewon Seong; Vishal Burungale; Myeongheon Seol; Chul Oh Yoon; Soon Hyung Kang; Wan-Gil Jung; Bong-Joong Kim; Jun-Seok Ha

doi:10.1021/acsomega.1c06720

Nanostructured Au Electrode with 100 h Stability for Solar-Driven Electrochemical Reduction of Carbon Dioxide to Carbon Monoxide

ACS Omega. 2022 Feb 28;7(11):9422-9429. doi: 10.1021/acsomega.1c06720. eCollection 2022 Mar 22.

Authors

Hyojung Bae¹, Chaewon Seong², Vishal Burungale², Myeongheon Seol³, Chul Oh Yoon³, Soon Hyung Kang^{1

4}, Wan-Gil Jung⁵, Bong-Joong Kim⁵, Jun-Seok Ha^{1

2

6}

Affiliations

¹ Optoelectronics Convergence Research Center, Chonnam National University, 77 Yongbong-ro, Gwangju 61186, Korea.
² School of Chemical Engineering, Chonnam National University, 77 Yongbong-ro, Gwangju 61186, Korea.
³ McScience Inc., Yeongtong-gu, Suwon 16690, Korea.
⁴ Department of Chemistry Education, Chonnam National University, 77 Yongbong-ro, Gwangju 61186, Korea.
⁵ School of Materials Science and Engineering, Gwangju Institute of Science and Technology (GIST), 123 Cheomdangwagi-ro, Gwangju 61005, Korea.
⁶ Energy Convergence Core Facility, Chonnam National University, 77 Yongbong-ro, Gwangju 61186, Korea.

Abstract

Solar-to-chemical energy conversion is a potential alternative to fossil fuels. A promising approach is the electrochemical (EC) reduction of CO₂ to value-added chemicals, particularly hydrocarbons. Here, we report on the selective EC reduction of CO₂ to CO on a porous Au nanostructure (pAu) cathode in 0.1 M KHCO₃. The pAu cathode anodized at 2.6 V exhibited maximum Faradaic efficiency (FE) for conversion of CO₂ to CO (up to 100% at -0.75 V vs reversible hydrogen electrode (RHE)). Furthermore, commercial Si photovoltaic cells were combined with EC systems (PV-EC) consisting of pAu cathodes and IrO₂ anodes. The triple-junction cell and EC system resulted in a solar-to-CO conversion efficiency (SCE) of 5.3% under 1 sun illumination and was operated for 100 h. This study provides a PV-EC CO₂ reduction system for CO production and indicates the potential of the PV-EC system for the EC reduction of CO₂ to value-added chemicals.