Atomic-level surface modification of ultrathin Bi2WO6 nanosheets for boosting photocatalytic CO2 reduction

Creating useful chemicals based on artificial CO 2 photoreduction is considered to be an attractive approach to address the environmental and energy crises. Currently, its selectivity with high conversion efficiency is still a grand challenge. Here, we report the refined substitution of Bi 3+ with Ag + in ultrathin Bi 2 WO 6 nanosheets through a liquid-phase cation exchange process, favoring a high selectivity towards the photocatalytic production of CO from CO 2 . The incorporation of Ag + could not only significantly promote the adsorption of both CO 2 and H 2 O molecules, but also facilitate the transfer of photogenerated carriers. The as-fabricated photocatalyst achieves a high CO generation rate of 116.96 μmol g −1 with a superb selectivity of 95.7 % after 6 h reaction without any sacrificial agent, approximate 4.2 times higher than that of pure Bi 2 WO 6 . The mechanism for photocatalytic CO 2 reduction is proposed, based on in-situ Fourier Transform Infrared spectrometry analyses and Density Functional Theory calculations.