Dynamic Active Sites in Bi(5)O(7)I Promoted by Surface Tensile Strain Enable Selective Visible Light CO(2) Photoreduction

Surface defects with abundant localized electrons on bismuth oxyhalide catalysts are proved to have the capability to capture and activate CO(2). However, bismuth oxyhalide materials are susceptible to photocorrosion, making the surface defects easily deactivated and therefore losing their function as active sites. Construction of deactivation-resistant surface defects on catalyst is essential for stable CO(2) photoreduction, but is a universal challenge. In this work, the Bi(5)O(7)I nanotubes with surface tensile strain are synthesized, which are favorable for the visible light-induced dynamic I defects generation. The CO(2) molecules absorbed on I defects are constantly reduced by the incoming photogenerated electrons from I-deficient Bi(5)O(7)I nanotubes and the successive protonation of CO(2) molecules is thus highly promoted, realizing the selective CO(2) conversion process via the route of CO(2)-COOH(−)-CO. The efficient and stable photoreduction of CO(2) into CO with 100% selectivity can be achieved even under visible light (λ >420 nm) irradiation benefited from the dynamic I defects as active sites. The results presented herein demonstrate the unique action mechanism of light-induced dynamic defects during CO(2) photoreduction process and provide a new strategy into rational design of deactivation-resistant catalysts for selective CO(2) photoreduction.