The efficient removal towards tetracycline via photocatalytic persulfate activation using the heterostructured UiO-66-NH2-CA-Cu/g-C3N4 composite

A series of UiO-66-NH2-CA-Cu/g-C3N4 (UCC1/CNx) heterogeneous photocatalysts were constructed via a facile physical mixing treatment of the covalently post-modified MOF (UiO-66-NH2-CA-Cu) and functional materials g-C3N4. The tetracycline removal by the photocatalysis coupled with persulfate activation were studied under white light irradiation. The optimal UCC1/CN20 photocatalyst showed the best photocatalytic performance, in which 94.0% TC could be efficiently eliminated (k = 0.08669 min(-1)) within 30 min. The satisfactory degradation performance could be ascribed to the effective separation of photogenerated electron-hole pairs over the heterogeneous binary structure, which were demonstrated by several characteristic technologies including photoluminescence spectra, electrochemical impedance spectroscopy, transient photocurrent response and Bader charge analysis based on density functional theory calculations. Moreover, a possible mechanism behind the photocatalytic degradation was proposed and further affirmed by the quenching experiments and electron spin resonance measurements. Our work may supply a feasible idea for treating wastewater contained organic pollutants based on the heterogeneous photocatalyst.