In Situ Growth of Cs3Bi2Br9 Quantum Dots on Bi-MOF Nanosheets via Cosharing Bismuth Atoms for CO2 Capture and Photocatalytic Reduction

Given the global warming caused by excess CO 2 accumulation in the atmosphere, it is essential to reduce CO 2 by capturing and converting it to chemical feedstock using solar energy. Herein, a novel Cs 3 Bi 2 Br 9 /bismuth-based metal–organic framework (Bi-MOF) composite was prepared via an in situ growth strategy of Cs 3 Bi 2 Br 9 quantum dots (QDs) on the surface of Bi-MOF nanosheets through coshared bismuth atoms. The prepared Cs 3 Bi 2 Br 9 /Bi-MOF exhibits bifunctional merits for both the high capture and effective conversion of CO 2, among which the optimized 3Cs 3 Bi 2 Br 9 /Bi-MOF sample shows a CO 2 –CO conversion yield as high as 572.24 μmol g –1 h –1 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 2 photoreduction efficiency does not decrease significantly. The mechanistic investigation uncovers that the intimate atomic-level contact between Cs 3 Bi 2 Br 9 and Bi-MOF via the coshared atoms not only improves the dispersion of Cs 3 Bi 2 Br 9 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 2 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 2 .