Inorganic-Framework Molecularly Imprinted CdS/TiO2 for Selectively Photocatalytic Degradation of Di (2-ethylhexyl) phthalate

Abstract

In order to improve the photocatalytic efficiency and selectivity of di (2-ethylhexyl) phthalate (DEHP) under solar-driven, the inorganic-framework molecularly imprinted CdS/TiO2, named as MIP-CdS/TiO2, was prepared by using DEHP as template molecule and tetrabutyl titanate as titanium source and functional monomer. The as-prepared MIP-CdS/TiO2 was characterized by scanning electron microscopy (SEM), X-ray energy spectrum (EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), UV-Vis Spectroscopy (UV-vis), X-ray photoelectron spectroscopy (XPS) and photoluminescence spectrum (PL). And the specific recognition and photocatalytic selectivity of MIP-CdS/TiO2 to DEHP were investigated. The results show that inorganic-framework molecular imprinting on the surface of CdS/TiO2 can result in existence of specific recognition sites of DEHP, extend and intensify the absorption visible light of CdS/TiO2, inhibit the recombination of the photo-induced electron-holes pairs. MIP-CdS/TiO2 has a specific recognition to DEHP. The binding selectivity coefficients of DEHP relative to its analogues DBP and DMP are 2.78 and 2.60, respectively. Compared with CdS/TiO2, MIP-CdS/TiO2 exhibits higher photocatalytic activity and selectivity for DEHP. Under simulated solar light irradiation, the degradation efficiency of DEHP photocatalyzed by MIP-CdS/TiO2 is 75.5%, which is 1.63 times as high as that of DEHP photocatalyzed by CdS/TiO2.