CeO₂–Mn₃O₄ Solid Solutions With Enhanced Photocatalytic Activity Toward Degradation of Phenolic Compounds

Abstract

In the present study, Mn3O4, CeO2, and their two solid solutions (10Ce–Mn3O4 and 10Mn–CeO2), synthesized by means of coprecipitation method, are investigated for UV light driven photocatalytic degradation of phenolic compounds. The two substituted nanocatalysts, 10Ce–Mn3O4 and 10Mn–CeO2, possess higher surface area, reduced bandgap, and distorted coordination environments compared to bare Mn3O4 and CeO2, respectively, as indicated by Rietveld refinement of PXRD data, BET, UV, and Raman analysis. 10Ce–Mn3O4 shows the best catalytic activity toward phenol degradation, which has been optimized to achieve promising performance of about 89.3% phenol degradation in 7 h UV irradiation at pH 3, 0.27 g L−1 catalyst dosage, and 25 ppm initial phenol concentration. Density of state (DOS) calculations support the observed catalytic activity trends, which show that on hetero atom substitution, bandgaps of 10Ce–Mn3O4 and 10Mn–CeO2 reduce owing to the incorporation of new energy level at the interband region. 10Ce–Mn3O4 exhibits promising activity retention up to fifth recycle. 10Ce–Mn3O4 is also tested for photodegradation 2,4‐dichlorophenol (2,4‐DCP), which shows very high degradation efficiency of 97.5%. Thus, this study points out a promising photocatalytic efficiency of 10Ce–Mn3O4 toward the degradation of organic pollutants present in wastewater.