Bioinspired Bi₂MoO₆ Electron Bridge and Carbon Nano-Island Heterojunctions for Enhanced Photothermal Catalytic CO₂ Reduction

Abstract

Photothermal catalysis utilizing the full solar spectrum to convert CO₂ and H₂O into valuable products holds promise for sustainable energy solutions. However, a major challenge remains in enhancing the photothermal conversion efficiency and carrier mobility of semiconductors like Bi₂MoO₆, which restricts their catalytic performance. Here, we developed a facile strategy to synthesize vertically grown Bi₂MoO₆ (BMO) nanosheets that mimic a bionic butterfly wing scale structure on a biomass-derived carbon framework (BCF). BCF/BMO exhibits high catalytic activity, achieving a CO yield of 165 μmol/(g·h), which is an increase of eight times compared to pristine BMO. The wing scale structured BCF/BMO minimizes sunlight reflection and increases the photothermal conversion temperature. BCF consists of crystalline carbon (sp²-C region) dispersed within amorphous carbon (sp³-C hybridized regions), where the crystalline carbon forms “nano-islands”. The N–C–O–Bi covalent bonds at the S-scheme heterojunction interface of BCF/BMO function as electron bridges, connecting the sp²-C nano-islands and enhancing the multilevel built-in electric field and directional trans-interface transport of carriers. As evidenced by DFT calculation, the rich pyridinic-N on the carbon nano-island can establish strong electron coupling with CO₂, thereby accelerating the cleavage of *COOH and facilitating the formation of CO. Biomass waste-derived carbon nano-islands represent advanced amorphous/crystalline phase materials and offer a simple and low-cost strategy to facilitate carrier migration. This study provides deep insights into carrier migration in photocatalysis and offers guidance for designing efficient heterojunctions inspired by biological systems.

Keywords

bioinspired materials / carbon nanoisland / carrier migration / CO₂ reduction / heterojunction / photothermal catalyst

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2025 The Author(s). Carbon Energy published by Wenzhou University and John Wiley & Sons Australia, Ltd.