Synthesis of heterostructured catalyst coupling MOF derived Fe2O3 with TiO2 for enhanced photocatalytic activity in anti-inflammatory drugs mixture degradation

Abstract

A new synthesis method to prepare the heterostructured catalyst MIL-101(Fe) derived Fe2O3 with TiO2 via microwave-assisted sol-gel route followed by pyrolysis was carried out. The mixed oxide catalyst was characterized by high-resolution transmission electron (HRTEM) and scanning electron microscopy (SEM), X-ray diffraction (XRD), UV–Vis DRS spectroscopy, N2 physisorption, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), photoluminescence (PL), and zetametry. The photocatalytic activity was evaluated in the degradation of the nonsteroidal anti-inflammatory drugs (NSAIDs), ibuprofen (IBP), and naproxen (NPX) in a mixture (10 mg/L/each one) at pH 3, using 1 g/L of the catalyst under visible light. The synthesized Fe2O3/TiO2 showed higher surface area, smaller average crystallite size, absorption in the visible range, and narrower band gap than TiO2, which enhanced the photocatalytic performance of TiO2 under visible radiation, allowing 91 and 100% degradation of IBP and NPX within 240 and 15 min of reaction, respectively. Moreover, 79.0% of mineralization of the mixture of NSAIDs in 240 min was achieved using the derived Fe2O3/TiO2 showing good reusability and stability even after three cycles of usage. In the photocatalytic process, holes were the dominant species for NSAIDs degradation.