Facile hydrothermal synthesis of carbon dots (CDs) doped ZnFe2O4/TiO2 hybrid materials with high photocatalytic activity

Abstract

Abstract In this study, a novel and highly efficient ternary photocatalytic ZnFe2O4/TiO2/CDs nanocomposite was successfully synthesized by a hydrothermal method. The properties and structures of the samples were characterized by X-ray diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Fourier transform infrared spectrometry (FT-IR), and photoluminescence spectrum (PL). The UV–vis diffuse reflectance spectrum was used to demonstrate that carbon quantum dots could increase the absorption of visible light wavelengths. When compared with TiO2/3.00 wt%CDs and ZnFe2O4/TiO2 nanocomposites, the ternary photocatalysts exhibited the enhanced photocatalytic activity under solar-spectrum irradiation. A low CDs content of 3.00 wt% in the ternary photocatalysts possessed excellent performance in the decomposition of Rhodamine B (RhB). Act as donator and receiver, CDs can efficiently improve the ability of electron transfer and separate the electron-hole pairs. OH and O2 − were confirmed to be involved in the photocatalytic degradation of RhB base on the Electron spin resonance (ESR) tests, and the photocatalytic mechanism of the ZnFe2O4/TiO2/3.00 wt%CDs was proposed. After four sequential operational cycles, the ZnFe2O4/TiO2/CDs maintained its photocatalytic efficiency, indicating its high photocatalytic stability. Therefore, our results provide a high efficient photocatalytic nanocomposite that synthetized by a facile method, and have implications in the removal of environmental persistent pollutants under ternary photocatalysts mediated solar degradation