Amplifying photo-Fenton redox synergy in Fe2O3/CeO2 heterostructured nanotubes for efficient blue-LED-activated degradation at pH 5

Herein, we report a Fe 2 O 3 /CeO 2 porous nanotube as a high-performance heterogeneous photo-Fenton-like catalyst, featuring a stable Fe-O-Ce heterojunction confirmed by XPS and TEM. This structural design, coupled with enhanced visible-light absorption induced by Fe 2 O 3 modification on CeO 2 , constitutes its core structural innovation. Under 440 nm blue LED irradiation and at pH 5, this composite achieves complete degradation of 80 mg/L methyl orange within 60 min with 0.5 mL of 15 % H 2 O 2 , exhibiting remarkable catalytic efficiency. Radical trapping experiments identify h + and OH as dominant active species, with O 2 − playing a secondary role. Notably, the catalyst maintains excellent performance after 4 cycles, highlighting its superior stability. Furthermore, CeO 2 facilitates electron transfer from H 2 O 2 to Fe 3+ , accelerating the Fe 3+ /Fe 2+ redox cycle. This accelerated cycle not only enhances H 2 O 2 activation and OH generation but also expands the pH operating range-overcoming the narrow pH limitation of traditional Fenton systems. Band analysis across the Fe 2 O 3 /CeO 2 heterojunction further clarifies the charge separation and transfer pathway underlying this enhanced catalytic behavior. With its exceptional co-catalytic activity, broad pH adaptability, and high stability, Fe 2 O 3 /CeO 2 porous nanotubes demonstrate great practical potential for real wastewater treatment. This work not only provides an efficient strategy for wastewater decontamination but also offers new insights into designing heterojunction-based catalysts for environmental remediation.