Fabrication of high visible light active LaFeO3/Cl-g-C3N4/RGO heterojunction for solar assisted photo-degradation of aceclofenac

Abstract

The designing of semiconductor based heterojunction has proved to be an effective strategy for developing more efficient photo-catalyst than single component photo-catalyst. Herein, we report the laboratory scale fabrication of a novel LaFeO3/Cl-g-C3N4/RGO (LCCR) heterojunction with enormous photocatalytic activity. The prepared nano-composite has been characterized using X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), field-emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM). The LaFeO3/Cl-g-C3N4/RGO (LCCR) nano-heterojunction exhibits excellent photocatalytic activity due to its reduced charge recombination rate. The photocatalytic potential of LCCR was tested for the photo degradation of aceclofenac drug as model pollutant. LCCR with an optimum dosage amount 200 mgL−1 has shown highest degradation of 96.4 % within 90 min of solar light exposure. Various operational parameters such as effect of pH, photocatalyst dosage, pollutant concentration and various ions has been investigated. The photo-degradation outcomes of LCCR nano-composite have been examined in terms of reaction kinetics, active radical identification experiments, high resolution mass spectrometry (HR-MS), chemical oxygen demand (COD) and total organic carbon (TOC) analysis. The photo-degradation experiment followed the pseudo first order kinetics with high rate constant k1 = 0.0461 min−1 and results for TOC and COD analysis shows that 53.2 % of TOC was removed, whereas COD was decreased to 22.4 %. This work shows promising photo-catalyst for treating pharmaceutical effluents.