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Nanoporous Au Thin Films on Si Photoelectrodes for Selective and Efficient Photoelectrochemical CO2 Reduction |
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| Authors: | Jun Tae Song Hyewon Ryoo Minhyung Cho Jaehoon Kim Jin‐Gyu Kim Sung‐Yoon Chung Jihun Oh |
| Affiliation: | 1. Graduate School of Energy, Environment, Water, and Sustainability, Korea Advanced Institute of Science and Technology (KAIST), Yuseong‐gu, Daejeon, Republic of Korea;2. KAIST Institute for NanoCentury, Korea Advanced Institute of Science and Technology (KAIST), Yuseong‐gu, Daejeon, Republic of Korea;3. Korea Basic Science Institute, Yuseong‐gu, Daejeon, Republic of Korea |
| Abstract: | An Si photoelectrode with a nanoporous Au thin film for highly selective and efficient photoelectrochemical (PEC) CO2 reduction reaction (CO2RR) is presented. The nanoporous Au thin film is formed by electrochemical reduction of an anodized Au thin film. The electrochemical treatments of the Au thin film critically improve CO2 reduction catalytic activity of Au catalysts and exhibit CO Faradaic efficiency of 96% at 480 mV of overpotential. To apply the electrochemical pretreatment of Au films for PEC CO2RR, a new Si photoelectrode design with mesh‐type co‐catalysts independently wired at the front and the back of the photoelectrode is demonstrated. Due to the superior CO2RR activity of the nanoporous Au mesh and high photovoltage from Si, the Si photoelectrode with the nanoporous Au thin film mesh shows conversion of CO2 to CO with 91% Faradaic efficiency at positive potential than the CO2/CO equilibrium potential. |
| Keywords: | CO2 conversion nanoporous Au thin film catalysts photoelectrochemical (PEC) CO2 reduction Si photoelectrodes |
