VO 4 -Modified Layered Double Hydroxides Nanosheets for Highly Selective Photocatalytic CO 2 Reduction to C1 Products.

The conversion of CO 2 into high-value added chemicals driven by solar energy is an effective way to solve environmental problems, which is, however, largely restricted by the competition reaction of the hydrogen evolution reaction (HER) and easy electron-hole recombination, etc. Herein, VO 4 -supported ultrathin NiMgV-layered double hydroxide (V/NiMgV-LDH) nanosheets are successfully fabricated, and the extended X-ray absorption fine structure (EXAFS) and density function theory (DFT) calculations reveal that VO 4 species are located on the top of V atoms in the NiMgV-LDH laminate. The V/NiMgV-LDH is proved to be highly efficient for the photocatalytic CO 2 reduction reaction (CO 2 PR) with high selectivity of 99% for C1 products and nearly no HER (<1%) takes place under visible light. Contrast experiments using NiMgV-LDH as the catalyst for CO 2 PR show a CO selectivity of 71.40% and a H 2 selectivity of 28.11%. Such excellent performance of V/NiMgV-LDH can be attributed to the following reasons: 1) the V/NiMgV-LDH modulates the band structure and promotes the separation of electrons and holes; 2) strong bonding between V/NiMgV-LDH and CO* and H* facilitates the hydrogenation to form CH 4 and inhibits the formation of by-product H 2 at the same time.