Cobalt nitride as a novel cocatalyst to boost photocatalytic CO₂ reduction

• Main Authors: Di, Jun, Chen, Chao, Zhu, Chao, Song, Pin, Duan, Meilin, Xiong, Jun, Long, Ran, Xu, Manzhang, Kang, Lixing, Guo, Shasha, Chen, Shuangming, Chen, Hailong, Chi, Zhen, Weng, Yu-Xiang, Li, Huaming, Song, Li, Wu, Minghong, Yan, Qingyu, Li, Shuzhou, Liu, Zheng
• Other Authors: School of Materials Science and Engineering
• Format: Article
• Language: English
• Published: 2022
• Subjects: Engineering::Materials; Co₂N; BiOBr
• Online Access: https://hdl.handle.net/10356/154718
• Institution: Nanyang Technological University

Photocatalytic CO₂ reduction has been regarded as an appealing pathway for CO₂ conversion to hydrocarbon fuels. To boost the CO₂ photoreduction performance, developing suitable cocatalyst on the photocatalysts is an efficient strategy. Herein, Co₂N is employed as novel noble-metal-free cocatalyst to promote the CO₂ photoreduction performance of BiOBr ultrathin nanosheets. The optimal Co₂N/BiOBr delivers a high selectivity CO formation rate of 67.8 µmol g−1 h−1 in pure water without sacrificial reagent or extra photosensitizer, roughly 6 times higher than BiOBr. Co2N can create strong electronic interactions with BiOBr, steering the electron transfer from BiOBr, across the interface to metallic Co₂N and finally to the surface. Apart from the charge separation steering, the activation energy barrier can be lowered on Co₂N surface via stabilize COOH* intermediates, tuning the rate-limiting step from the formation of COOH* on BiOBr to the formation of CO* on Co₂N, jointly optimize the CO₂ photoreduction activity. This strategy affords an accessible pathway for designing cocatalysts for efficient CO₂ photoreduction.