Facet-specific Active Surface Regulation of Bi x MO y (M=Mo, V, W) Nanosheets for Boosted Photocatalytic CO 2 reduction.

Photocatalytic performance can be optimized via introduction of reactive sites. However, it is practically difficult to engineer these on specific photocatalyst surfaces, because of limited understanding of atomic-level structure-activity. Here we report a facile sonication-assisted chemical reduction for specific facets regulation via oxygen deprivation on Bi-based photocatalysts. The modified Bi 2 MoO 6 nanosheets exhibit 61.5 and 12.4 μmol g -1 for CO and CH 4 production respectively, ≈3 times greater than for pristine catalyst, together with excellent stability/reproducibility of ≈20 h. By combining advanced characterizations and simulation, we confirm the reaction mechanism on surface-regulated photocatalysts, namely, induced defects on highly-active surface accelerate charge separation/transfer and lower the energy barrier for surface CO 2 adsorption/activation/reduction. Promisingly, this method appears generalizable to a wider range of materials.