Hydrothermally synthesized CeO2/ZnO nanocomposite photocatalysts for the enhanced degradation of Reactive Orange 16 dye

Abstract

In this work, in order to improve the photocatalytic efficiency of ZnO, the optimal CeO2 content in ZnO powders was determined by varying the quantity of CeO2 from 0 to 10 mol%. The structural, microstructural, optical, textural, and photocatalytic properties of the hydrothermally obtained ZnO and CeO2/ZnO nanocomposites have been investigated by using the XRPD, FESEM, HRTEM/SAED, BET, and UV–Vis techniques. Detailed characterization revealed that CeO2, having spherical nanodots of about 5 nm with a large surface area, was distributed onto the ZnO surface, whose crystallites displayed a bimodal distribution, from nano-to micro-crystals. The morphology of ZnO is a combination of nanograins and microrods that further makes a 3-D tie-like morphology. The nanocomposite containing 5 mol% of CeO2 showed about 30% better photocatalytic efficiency in the degradation of Reactive Orange 16 dye compared to other samples under simulated solar radiation. In addition, the kinetics and mechanism of photocatalytic degradation were also proposed based on the photocatalytic activity and scavenger tests.