In Situ Growth of Cs 3 Bi 2 Br 9 Quantum Dots on Bi-MOF Nanosheets via Cosharing Bismuth Atoms for CO 2 Capture and Photocatalytic Reduction.

Given the global warming caused by excess CO accumulation in the atmosphere, it is essential to reduce CO by capturing and converting it to chemical feedstock using solar energy. Herein, a novel CsBiBr/bismuth-based metal-organic framework (Bi-MOF) composite was prepared via an in situ growth strategy of CsBiBr quantum dots (QDs) on the surface of Bi-MOF nanosheets through coshared bismuth atoms. The prepared CsBiBr/Bi-MOF exhibits bifunctional merits for both the high capture and effective conversion of CO, among which the optimized 3CsBiBr/Bi-MOF sample shows a CO-CO conversion yield as high as 572.24 μmol g h under the irradiation of a 300 W Xe lamp. In addition, the composite shows good stability after five recycles in humid air, and the CO photoreduction efficiency does not decrease significantly. The mechanistic investigation uncovers that the intimate atomic-level contact between CsBiBr and Bi-MOF via the coshared atoms not only improves the dispersion of CsBiBr QDs over Bi-MOF nanosheets but also accelerates interfacial charge transfer by forming a strong bonding linkage, which endows it with the best performance of CO photoreduction. Our new finding of bismuth-based metal-organic framework/lead-free halide perovskite by cosharing atoms opens a new avenue for a novel preparation strategy of the heterojunction with atomic-level contact and potential applications in capture and photocatalytic conversion of CO.