Enhanced photodegradation of 2,4-dichlorophenoxyacetic acid using a novel TiO2@MgFe2O4 core@shell structure

Abstract

A novel TiO₂@MgO-Fe₂O₃ core-shell structure has been synthesized via a hydrolysis and co-precipitation method followed by calcination at 500 °C and has proven to be an efficient photocatalyst. The obtained TiO₂@MgO-Fe₂O₃ core-shell was characterized by scanning electron microscopy, X-ray diffraction, and UV-Vis diffused reflectance techniques. Its photocatalytic activity toward 2,4-dichlorophenoxyacetic acid (2,4-D) was investigated in aqueous solutions with and without visible light irradiation in the presence and absence of hydrogen peroxide. It was revealed that a strong electronic coupling exists between two components within the TiO₂@MgO-Fe₂O₃ core-shell structure. The present findings clearly highlight that TiO₂@MgO-Fe₂O₃ exhibits excellent photocatalytic activity under visible light irradiation in the presence of H₂O₂. More than 83% degradation of 2,4-D was observed within 240 min, at an initial concentration of 100 mg L^-1 with 0.5 g of catalyst per liter. Moreover, the material showed high chemical stability after four consecutive experiments with no significant difference in the rate of photocatalytic degradation. Therefore, the results reported herein offer a green, low cost and highly efficient photocatalyst for environmental remediation.

Keywords: 2,4-Dichlorophenoxyacetic acid; Hydrogen peroxide; TiO(2)@MgO-Fe(2)O(3) photocatalyst; Visible-light photodegradation.