Fabrication of α-Fe2O3/TiO2 heterojunction for photocatalytic degradation of doxycycline hydrochloride

In this work, flower-like TiO 2 (TiO 2 -F) was first prepared by modulating the morphology of TiO 2 , and then, α-Fe 2 O 3 was loaded onto TiO 2 -F to successfully prepare α-Fe 2 O 3 /TiO 2 -F heterojunction materials. The material showed excellent degradation properties of doxycycline hydrochloride under visible light. The photocatalytic degradation efficiency of α-Fe 2 O 3 /TiO 2 -F2 for doxycycline hydrochloride under visible light reached 95.76 % in 120 min, and its pseudo-first-order degradation rate constant was 0.02647 min −1 , which was 3.68 and 2.01 times higher than those of α-Fe 2 O 3 and TiO 2 alone, respectively. This good photocatalytic performance is attributed mainly to the introduction of α-Fe 2 O 3 to form a Type II heterojunction with floral TiO 2 (TiO 2 -F), which is capable of promoting the separation of electron–hole pairs of photocatalysts and exhibiting a stronger redox capacity. The material exhibits notable stability and maintains high degradation efficiency even after undergoing multiple cycles. Furthermore, free radical trapping experiments and electron spin resonance (ESR) characterization revealed that hydroxyl radicals play a dominant role in this system. Finally, the degradation pathways were analyzed, and relevant toxicological analyses were performed, indicating that the toxicity of doxycycline hydrochloride gradually decreased during the photocatalytic degradation process.