Microwave-Assisted Photocatalytic Degradation of Dimethyl Phthalate Over a Novel ZrO x Catalyst

Abstract

Abstract

A novel microwave-assisted photocatalytic active ZrO _x catalyst, which has mix-valences and wide bandgap, has been prepared by cetyltrimethylammonium bromide–assisted hydrothermal method. Structural and optical properties were characterized by X-ray photoelectron spectroscopy, X-ray diffraction, transmission electron microscopy, N₂ adsorption–desorption, and UV–vis techniques. Total organic carbon (TOC) removal of dimethyl phthalate (DMP) (100 mL, 50 mg L⁻¹) with 1 g L⁻¹ ZrO _x approached 84% after a 30-min reaction, which was about 15% and 11% higher than ZrO₂ and P25 TiO₂, respectively. TOC removal of DMP by microwave-assisted photocatalytic process followed pseudo–first-order kinetics in all cases, and ZrO _x evidently accelerated the degradation of DMP. Degradation half-life time of DMP using ZrO _x was shortened 43% and 34%, compared with ZrO₂ and P25 TiO₂, respectively. A possible catalytic mechanism of ZrO _x was proposed based on microwave response and interfacial charge transfer analyses. Further research on ZrO _x may develop a promising new generation of highly efficient catalysts for the microwave-assisted photocatalytic process for environmental remediation.