Cellulose-based tubular CuO/Cu2O-Cu7S4 S-type heterojunctions directional accelerate Cu2+/Cu+ cycling for photo-Fenton-like degradation of antibiotics

In this study, a tubular CuO/Cu 2 O-Cu 7 S 4 (COS-3) ternary heterojunction photocatalyst was successfully prepared by electroless plating, high-temperature oxidation and hydrothermal vulcanization for the efficient degradation of tetracycline antibiotics in water environment, combined with the advantages of cellulose carrier. TEM, XRD and XPS characterization confirmed the tight coupling of the three-phase components, and the regular peak shift of O 1 s and Cu 2p confirmed the directional migration of electrons, marking the successful construction of the S-type heterojunction. In the visible light-driven photocatalytic/Fenton-like system, COS-3 showed the best activity, and under the optimized reaction conditions (catalyst concentration: 0.4 g/L; pollutant concentration: 100 mg/L; PMS concentration: 0.4 g/L; the light source is 300 watts xenon lamp); in the dark adsorption process (30 min), the removal rates of TC and OTC were 21.1% and 30.5%, respectively. Under visible light conditions, the degradation efficiency of TC and reached 39.8% and 43.6% within 20 min. After adding PMS, the removal efficiency of TC and OTC reached 94.9% and 95.7% within 20 min. Compared with the photocatalytic reaction alone, the removal efficiency increased by 2.38 and 2.19 times, respectively. The mechanism study reveals that the S-type heterojunction significantly promotes the spatial separation of photogenerated carriers, and the high-energy electrons enriched on the surface of Cu 7 S 4 accelerate the Cu 2+ /Cu + redox cycle, thereby efficiently activating PMS to produce active oxide species dominated by ·SO 4 - . ECOSAR evaluation further confirmed that the system can mineralize antibiotics into low-toxic products, with excellent environmental safety and application prospects. This study proposes a scalable engineering strategy that combines the resource utilization of natural lignocellulose with efficient photo-Fenton-like synergistic catalysis to show broad application prospects in the treatment of industrial antibiotic wastewater.