Construction of CeO2/YMnO3 and CeO2/MgAl2O4/YMnO3 photocatalysts and adsorption of dyes and photocatalytic oxidation of antibiotics: Performance prediction, degradation pathway and mechanism insight

Abstract

A simple two step method was developed for fabrication of ternary heterojunctions of YMnO3/CeO2/MgAl2O4 (YCM) composite photocatalysts, which shows well adsorption capacity for the adsorption of Congo red and photocatalytic activity for the degradation of tetracycline hydrochloride (TC-HCl) under visible light irradiation. Systematic studies suggested that the YCM composite photocatalysts exhibit high optical absorption coefficient, charge carrier transfer and separation efficiency, adsorbed oxygen concentration and interface defect, high adsorption capacity and photocatalytic activity. The back propagation (BP) neural network model, whale optimization algorithm (WOA) and genetic algorithm (GA) were used to predict the adsorption capacity of YC composite photocatalysts, and GA model demonstrated the best predictive ability. The high adsorption can be assigned to the synergistic effect of electrostatic interaction, ion exchange and hydrogen bonding. Capture experiments revealed that photogenerated holes, hydroxyl and superoxide radicals are the main active species during the photocatalytic process for the YCM composite photocatalysts. Possible degradation pathways of TC-HCl over YCM composite photocatalysts under visible light irradiation were proposed through the identification of intermediates using high-performance liquid chromatography-tandem mass spectrometry (HPLC–MS). This work demonstrated a huge potential of YCM composite photocatalysts as an eco-friendly photocatalyst for adsorption of dye and degradation of drug.