The design and synthesis of unique novel heterostructures for high-performance photocatalytic activity has exerted a tremendous fascination and has recently attracted intensive attention. In this work, a branch-like α-Fe2O3/TiO2 heterostructure has been synthesized controllably through an electrospinning method combined with a hydrothermal approach. The backbone of the heterostructure is composed of a 3D porous TiO2 nanofiber (∼70 nm in diameter) network with plenty of α-Fe2O3 nanorods (100–200 nm in length) deposited on them. The novel branch-like nanocomposites have an abundantly porous structure as well as large surface areas (up to 42.8 m2 g−1). In addition, their visible light photodegradation behaviour towards organic dyes, including Congo red (CR), methylene blue (MB), eosin red (ER) and methyl orange (MO), was investigated. Their excellent photocatalytic performances are attributed to their large surfaces, improved visible light absorption and high separation efficiency of the photogenerated electrons/holes. Furthermore, the degradation process was further studied by varying the amount of α-Fe2O3 deposited. The sample α-Fe2O3/TiO2-3 possessed the best performance to efficiently decolor CR solution even at a high concentration of 50 mg L−1 (160 min, 94 mg g−1), ascribed to the high adsorption capacity derived from the large surface, strong electrostatic interaction and structural match between α-Fe2O3/TiO2-3 and CR. These α-Fe2O3/TiO2 heterostructures exhibit great potential for decontamination of organic pollutants in waste water under visible light.
Caixia Deng,Shuang Li,JiaYu Wang,Qiang Yang,Hui Chen,Fenglin Tang,Xiupei Yang
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.
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