《J. Am. Soc. Chem.》: Regulated Photocatalytic CO₂-to-CH₃OH Pathway by Synergetic Dual Active Sites of Interlayer  

Jiacong Wu,⁺ Fei Huang,⁺ Qinyuan Hu,⁺ Dongpo He, Wenxiu Liu, Xiaodong Li*, Wensheng Yan, Jun Hu, Junfa Zhu, Shan Zhu, Qingxia Chen*, Xingchen Jiao*, and Yi Xie*

Herein, composites of nanosheets with van der Waals contact are employed to disclose how the interlayer-microenvironment effects the product selectivity of carbon dioxide (CO₂) photoreduction. The concept of composites of nanosheets with dual active sites is introduced to manipulate the bonding configuration and promote the thermodynamic formation of methanol (CH₃OH). As a prototype, the CoNi₂S₄-In₂O₃ composites of nanosheets are prepared, in which high resolution transmission electron microscopy imaging, X-ray photoelectron spectroscopy spectra, and Zeta potential tests confirm the presence of van der Waals contacts rather than chemical bonding between the In₂O₃ nanosheets and the CoNi₂S₄ nanosheets within the composite. The fabricated CoNi₂S₄-In₂O₃ composites of nanosheets exhibits the detection of the key intermediate *CH₃O during CO₂ photoreduction through in situ Fourier transform infrared spectra, while the In₂O₃ nanosheets and CoNi₂S₄ nanosheets alone do not show this capability, further verified by the density functional theory calculations. Accordingly, the CoNi₂S₄-In₂O₃ composites of nanosheets show the ability to produce CH₃OH, whereas the CoNi₂S₄ and In₂O₃ nanosheets solely generate carbon monoxide product from CO2 photoreduction.

Figure 1. Schematic illustration for CO₂ reduction pathways over the composite catalyst with van der Waals contact.