Photosensitizing single-site metal−organic framework enabling visible-light-driven CO2 reduction for syngas production

[Display omitted] •Integration of photosensitizer and single site catalyst into a UiO-67 framework.•Visible light driven photocatalytic CO2 reduction into syngas.•The H2/CO ratios in syngas can be widely adjusted from 1.6 to 5.6.•Syngas (H2/CO = 2:1) production yield as high as 13,600 μmol·g−1 in 16 h.•The photocatalytic activity of composite was 29.2-fold higher than that of its homogeneous counterpart. Photocatalytic CO2 reduction into syngas (CO and H2) is one of sustainable strategies for recycling CO2 into value-added products. Herein, a simple and effective two-step self-assembly process was developed to functionalize phosphorescent metal-organic framework (MOF) with single site catalyst. The resulting (Co/Ru)n-UiO-67(bpydc) supplied molecular platform to enable fast multielectron injection from photosensitizers (PSs) to Co-catalyst, leading to the first MOF-based composite photocatalyst for efficient syngas production with a yield of 13,600 μmol·g−1 (H2 : CO = 2 : 1) in 16 h, 29.2-fold higher than that of its homogeneous counterpart. The H2/CO ratios can be well controlled by carefully adjusting the molar ratio of PS/catalyst in the MOF platform and the water content in the photocatalytic system. This work provides a prospective strategy for recycling CO2 into H2-rich syngas by merging PSs and single-site catalysts into a MOF platform.