Design of multifunctional hybrid metal-organic frameworks (ZIF67/MIL125/ZIF8) for enhanced photocatalytic degradation, and green chemical conversion

This multifunctional hybrid metal-organic framework (MOF), ZIF67/MIL125/ZIF8, was synthesised using a post-synthetic integration of preformed MOFs approach to achieve efficient carbon dioxide (CO 2 ) reduction, nitrogen (N 2 ) fixation, and photocatalytic decomposition under visible light. The composite combines titanium-based MIL125 with zinc- and cobalt-based ZIFs, improving structural stability, separation of charges, and the light absorption capacity. The effective development of the ternary heterojunction and its beneficial optoelectronic characteristics were validated by comprehensive characterization techniques such as XRD, FTIR, FE-SEM, XPS, HR-TEM, and PL. The hybrid catalyst performed better than each of the MOF components exhibited superior performance, achieving over 90% ciprofloxacin breakdown in 60 min under visible light irradiation. Studies using reactive oxygen species trapping showed that the primary oxidative species leading to the degradation were superoxide radicals (•O 2 − ). In addition, the material demonstrated a notable NH 3 yield in both pure and atmospheric N 2 purging, indicating efficient photocatalytic N 2 fixation. Furthermore, the material demonstrated its potential for sustainable chemical conversion through facilitating the photoreduction of CO 2 into essential hydrocarbons. The photocatalyst exhibited superior durability and reusability over multiple cycles. ZIF67/MIL125/ZIF8 represents a promising multifunctional photocatalyst for addressing sustainability challenges through solar-driven pollutant degradation and renewable resource conversion.