Cobalt-Based Coordination Polymer with Synergistic Active Sites for Visible-Light-Driven CO₂-to-CO Conversion

An unprecedented cobalt(II)-coordination polymer, [Co(L’)(bidpe)]n, was successfully synthesized via a green hydrothermal approach (160 °C, 72 h) with 59% yield, demonstrating significant cost advantages over noble-metal catalysts. Single-crystal X-ray diffraction reveals a unique topological framework stabilized by π–π stacking interactions (space group P21/c), exhibiting exceptional thermal stability (<2% weight loss below 310 °C by TGA) and structural integrity postcatalysis. Comprehensive characterization (PXRD, FTIR, XPS, and SEM-EDS) confirms the well-defined coordination environment and homogeneous elemental distribution. Through systematic parameter optimization, we established a standardized photocatalytic system achieving a remarkable CO production rate of 48.1993 μmol·g–1·h–1 under visible light (420 nm) using an efficient combination with a commercial Ru photosensitizer (35 mg) in an optimized DMA/H2O/TEOA (3:2:1) solvent system. The material maintains excellent stability, as verified by postreaction PXRD analysis. This work presents a cost-effective, stable, and scalable strategy for CO2-to-CO conversion.