Strain-Engineering of Bi12O17Br2 Nanotubes for Boosting Photocatalytic CO2 Reduction

The effect of surface tensile strain on the photocatalysis is an open question. In this work, strain engineering has been demonstrated to promote the performance of photocatalysis by curved 2D materials into nanotubes. The surface atomic tensile strain in the Bi12O17Br2 nanotubes is evidenced by the complementary approaches of HAADF STEM imaging and XAFS, which reveals the refined local atomic arrangement of Bi atoms. The engineered surface atomic tensile strain is found to favors CO2 adsorption and activation, charge separation, and CO desorption, as well as lowers ratelimiting step energy barrier. Compared with the 2D Bi12O17Br2 nanoplates, the tensile strain tuned nanotubes shows 14.4 times increased CO2 photoreduction activity to produce CO, in which the generation rate of CO can arrive 34.5 mu mol g(-1) h(-1). This work offer insights into the relationship between surface tensile strain and CO2 photoreduction behavior at the atomic level and provides an accessible way for designing highefficiency photocatalysts.