Regulated Photocatalytic CO-to-CHOH Pathway by Synergetic Dual Active Sites of Interlayer.

Herein, composites of nanosheets with van der Waals contacts are employed to disclose how the interlayer-microenvironment affects the product selectivity of carbon dioxide (CO) 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 (CHOH). As a prototype, the CoNiS-InO 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 InO nanosheets and the CoNiS nanosheets within the composite. The fabricated CoNiS-InO composites of nanosheets exhibit the detection of the key intermediate *CHO during CO photoreduction through in situ Fourier transform infrared spectra, while the InO nanosheets and CoNiS nanosheets alone do not show this capability, further verified by the density functional theory calculations. Accordingly, the CoNiS-InO composites of nanosheets show the ability to produce CHOH, whereas the CoNiS and InO nanosheets solely generate carbon monoxide products from CO photoreduction.