Enhanced orientation photocatalytic ability of 1D inorganic imprinted oxygen vacancy CdO0.5S0.5 by confining the target to the specific reaction sites enriched in electrons

Abstract

The conventional means for selectively capturing and subsequently degrading specific organic pollutants entails the development of an inorganic imprinted photocatalytic material with visible light response, high activity, and high stability. Hence, the inorganic imprinted oxygen vacancy CdO0.5S0.5 (II-OV-CdO0.5S0.5) was prepared by S2- ion exchange assisted inorganic imprinting technology. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD) patterns, X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR) and thermogravimetry analysis (TGA) were used to comprehensively prove that S element only permeated the surface of the material, and there were imprinted cavities and a few oxygen defects caused by inorganic imprinting. Photoelectrochemistry experiments and DFT theoretical calculation showed that the electrons gathered near the oxygen defects around the imprinted cavities (specific reaction sites), and the reactive center formed was more favorable to the specific adsorption of tetracycline (TC). Since TC was confined to the specific reaction sites enriched in electrons, the apparent rate constant of II-OV-CdO0.5S0.5 (0.0220 min−1) was 2.18 times that of CdO0.5S0.5 (0.0101 min−1) after TC photodegradation for 60 min under visible light. More importantly, although the space size of ciprofloxacin (CIP) was smaller than that of TC, because the imprinted cavities not only had a size effect, but also possessed the specific adsorption sites, there was no significant enhancement in the degradation of CIP. Therefore, II-OV-CdO0.5S0.5 demonstrated excellent orientation photocatalytic ability for the target (TC), under the premise of improving the photodegradation of the target, II-OV-CdO0.5S0.5 effectively inhibited the photodegradation of other reference pollutants. This work provides an exemplary method for the design of functionalized photocatalytic materials and the orientation removal of specific pollutants.