Rational design of Ce-doped CdS/N-rGO photocatalyst enhanced interfacial charges transfer for high effective degradation of tetracycline

Abstract

The charge carrier separation efficiency and the adsorption capacity of the photocatalyst usually affect the degradation rate of antibiotics. Herein, Cerium-doped leaf-like CdS (Ce-CdS) modified with ultrathin N-doped rGO (N-rGO) composites were successfully constructed (Ce-CdS/N-rGO) to investigate the removal efficiency of tetracycline (TC). X-ray photoelectron spectroscopy (XPS) and photoelectrochemical results revealed that Ce ions doped in CdS acting as the electron capture sites facilitated the interfacial charge transfer. Theoretical calculation (DFT) results indicated that the interfacial effect between Ce-CdS and ultrathin N-rGO promoted the transfer of photogenerated electrons under the synergistic effect between the doping and interface modification strategy. The optimized Ce5-CdS/N-rGO20 composites had the maximum TC removal capability (94.5%) and maintained a stable cycling performance. In addition, the adsorption-driven photocatalytic degradation pathway of TC was studied through mass spectrometry (MS) and in-situ Fourier transform infrared spectroscopy (in-situ FTIR). This study will provide an effective strategy for the construction of efficient photocatalytic composites for wastewater treatment.