In-situ growth of MOFs on porous geopolymer spheres for continuous-flow PMS degradation of antibiotics

A metakaolin/slag-based porous geopolymer (non-sintered ceramic) was prepared using a simple direct molding method, and the copper metal–organic frameworks (Cu-MOFs) were grown in situ via a solvothermal process. The Cu-MOFs/geopolymer composites achieve a ~98% degradation rate for tetracycline hydrochloride (TCH) within 10 min via peroxymonosulfate (PMS) activation at pH = 11. Radicals (·OH, SO₄^•−, and O₂^•−) and non-radicals (¹O₂) were identified as the dominant reactive oxygen species (ROS) participating in the catalytic process. Cu-MOFs/geopolymer acts as an electron transfer medium between TCH molecules and PMS molecules, enabling the efficient degradation of TCH. Furthermore, the catalytic system exhibited excellent cyclic stability, pH adaptability, and resistance to ionic interference, demonstrating superior performance in a flow-through fixed-bed reactor simulating real wastewater. The practical application of this system in wastewater treatment can be beneficial for reducing energy consumption, enhancing environmental sustainability, and lowering catalyst costs.