CO<sub>2</sub>‐Reductive, Copper Oxide‐Based Photobiocathode for Z‐Scheme Semi‐Artificial Leaf Structure
Su Keun Kuk, Jinha Jang, Jin‐Hyun Kim, Young‐Jun Lee, Young Sin Kim, Bonhyeong Koo, Yang Woo Lee, Jong Wan Ko, Byungha Shin, Jung‐Kul Lee, Chan Beum Park
Abstract
Abstract Green plants convert sunlight into high‐energy chemicals by coupling solar‐driven water oxidation in the Z‐scheme and CO 2 fixation in the Calvin cycle. In this study, formate dehydrogenase from Clostridium ljungdahlii (ClFDH) is interfaced with a TiO 2 ‐coated CuFeO 2 and CuO mixed (ClFDH–TiO 2 |CFO) electrode. In this biohybrid photocathode, the TiO 2 layer enhances the photoelectrochemical (PEC) stability of the labile CFO photocathode and facilitates the transfer of photoexcited electrons from the CFO to ClFDH. Furthermore, inspired by the natural photosynthetic scheme, the photobiocathode is combined with a water‐oxidizing, FeOOH‐coated BiVO 4 (FeOOH|BiVO 4 ) photoanode to assemble a wireless Z‐scheme biocatalytic PEC device as a semi‐artificial leaf. The leaf‐like structure effects a bias‐free biocatalytic CO 2 ‐to‐formate conversion under visible light. Its rate of formate production is 2.45 times faster than that without ClFDH. This work is the first example of a wireless solar‐driven semi‐biological PEC system for CO 2 reduction that uses water as an electron feedstock.