Photoelectrocatalytic evaluation of EG-CeO2 photoanode on degradation of 2,4-dichlorophenol

Abstract

Herein, we report the photoelectrocatalytic degradation of 2,4-dichlorophenol as a model chlorinated phenolic compound on exfoliated graphite-cerium(IV) oxide (EG-CeO2) photoelectrode. The EG-CeO2 nanocomposites with and without trimethoxymethylsilane (TMOMS) were synthesized using impregnation ultrasonic agitation and comprehensively characterized by XRD, FTIR, Raman, TGA, DSC, FESEM, TEM, EDS, UV–Vis DRS, BET, XPS, and AFM. The SEM results revealed that the CeO2 material was entrapped within the cavities and on the surface of EG sheets. Electrochemical studies were performed using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and linear sweep voltammetry (LSV). Photoelectrocatalytic degradation of 2,4-dichlorophenol dissolved in 0.1 M Na2SO4 electrolyte was performed with chronoamperometric technique. The EG-CeO2 (TMOMS) displayed higher removal efficiency under simulated light compared to EG and EG-CeO2, respectively. The degradation efficiency of 98.7% was attained with EG-CeO2 (TMOMS) under optimum conditions of pH 6.2 and current density of 8 mA cm−2. Total organic carbon removal of about 92.6% was recorded during the degradation of 2,4-DCP under optimum conditions for 180 min. Based on the results obtained, the low-cost EG-CeO2 (TMOMS) photoelectrode has lent itself into possibility of photoelectrocatalytic degradation of organic water pollutants and can be extended to environmental samples application.