Dual Enhancement of *CO Binding and *H Supply by Photothermal Heterojunction Nanosheets toward High-Efficiency CO 2 Methanation

作者：Mingyu Wu, Xiangning Wang, Youbin Zheng, Peng Lan, Awei Hu, Juncheng Zhu, Bangwang Li, Yang Wu, Jun Hu, Chengyuan Liu, Junfa Zhu, Yang Pan, Meng Zhou, Yongfu Sun, Yi Xie · 发表于：Journal of the American Chemical Society · 年份：2025 · DOI：10.1021/jacs.5c17165 · 被引用次数：33 · 研究领域：Advanced Photocatalysis Techniques、CO2 Reduction Techniques and Catalysts、Carbon dioxide utilization in catalysis

Photocatalytic CO 2 methanation presents a sustainable route to mitigate greenhouse effect and advance carbon neutrality. However, the pivotal *CO protonation step to *CHO, essential for CH 4 formation, is kinetically and thermodynamically disfavored over *CO desorption, limiting the overall efficiency. To overcome this limitation, we engineer photothermal-coupled Bi 2 S 3 –SnS 2 heterojunction nanosheets that concurrently enhance *CO binding and *H supply, enabling efficient reduction of CO 2 to CH 4 . Comprehensive characterizations via femtosecond transient absorption spectroscopy, in situ X-ray photoelectron spectroscopy, and theoretical calculations confirm a direct Z-scheme charge transfer mechanism. This mechanism promotes charge accumulation at catalytic sites, strengthening *CO binding and thermodynamically switching the dominant pathway from *CO desorption (+1.00 eV) to *CO protonation (−0.88 eV). Additionally, the favorable valence band alignment in the heterojunction facilitates H 2 O dissociation to produce *H. Crucially, H/D kinetic isotopic effect measurements and in situ Fourier-transform infrared spectroscopy reveal a pronounced photothermal effect within the heterojunction, where light-induced heat accelerates H 2 O dissociation and *H transfer kinetics, thereby enhancing the *H supply for *CO protonation. Consequently, the Bi 2 S 3 –SnS 2 heterojunction nanosheets achieve a remarkable CH 4 production rate of 341.4 μmol g –1 h –1, representing a 23.1-fold en...