Efficient selectivity of dual-metal intermediate structure in metal-organic frameworks-based photocatalyst for customized the pathway of CO₂ reduction to CO

The capture and utilization of CO₂ are critical for protecting the environment and ensuring the sustainable development of society. Given the challenges in separating multiple C1 products (CO, CH_4, etc.) with similar reduction potentials, achieving high selectivity for a single reduction product while maintaining high conversion efficiency is essential. In this study, a photocatalyst with NH₂-MIL-125-Ti/Cu dual-metal active sites was developed by introducing Cu²⁺ in situ. The synergistic interaction between oxygen vacancies that capture CO₂ and the Cu-Ti dual active sites formed by CuCOTi intermediates preferentially facilitated the generation of CO. As a result, high CO selectivity was achieved during the CO₂ photoreduction process. The experimental results indicate that NH₂-MIL-125-Ti/Cu5 achieves nearly 100 % selectivity for CO under visible-light irradiation, with a CO₂-to-CO conversion rate of 598.2 μmol g^-1 h^-1, representing a 108.28 % improvement compared to NM. This study provides a novel strategy for designing and synthesizing more efficient and selective photocatalysts.