Microwave-assisted photocatalytic degradation of dimethyl phthalate over a novel ZrO_x catalyst

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) (100mL, 50mg L^-1) with 1g 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.