CuCo<sub>2</sub>S<sub>4</sub>/g-C<sub>3</sub>N<sub>4–<i>x</i></sub> S-Scheme Heterojunction for Photothermal-Assisted Photocatalytic CO<sub>2</sub> Reduction
Fangde Liu, Yanjie Song, Renzhi Xiong, Deyue Duan, Xiao Xiao, Yanhe Xiao, Baochang Cheng, Shuijin Lei
Abstract
Photocatalytic conversion of CO 2 into chemical fuels has emerged as a research hotspot, aiming to mitigate the rapid depletion of fossil fuels and alleviate global warming. However, the inherent low carrier separation efficiency and limited solar light utilization of photocatalysts lead to unsatisfactory CO 2 conversion efficiency. In this study, an appealing CuCo 2 S 4 /g-C 3 N 4– x S-scheme heterostructure is successfully fabricated by a simple polyol reflux method. Notably, nitrogen vacancies enhance the Fermi level difference between CuCo 2 S 4 and g-C 3 N 4– x, resulting in a stronger interfacial built-in electric field. The full-spectrum strong optical absorption capability endows the synthesized catalysts with superior light-harvesting property. The photothermal effect-induced temperature increase accelerates the cyclic process of CO 2 adsorption and CO desorption on the catalyst surface. Most importantly, the S-scheme charge transfer pathway ensures the efficient separation of photogenerated carriers. Thanks to these synergistic benefits, CuCo 2 S 4 /g-C 3 N 4– x exhibits exceptional photothermal-assisted photocatalytic CO 2 reduction performance. Under simulated sunlight, the average CO production rate of CuCo 2 S 4 /g-C 3 N 4– x reaches 24.64 μmol g –1 h –1, which is 12.1 and 27.1 times higher than that of g-C 3 N 4 and CuCo 2 S 4, respectively. This study offers a novel strategy for designing photocatalysts with outstanding CO 2 conversion performance.