Influence of mass ratio and calcination temperature on physical and photoelectrochemical properties of ZnFe-layered double oxide/cobalt oxide heterojunction semiconductor for dye degradation applications

A visible light-active photoelectrocatalyst, ZnFe-layered double oxide (LDO)/cobalt(II,III) oxide (Co3O4) composites were obtained by calcining the Co loaded ZnFe-layered double hydroxide (LDH) prepared by a hydrothermal and microwave hydrothermal method. The morphological studies revealed that the ZnFe-LDO/Co3O4 composites exhibited a flower-like structure comprising Co(3)O(4 )nanowires and ZnFe-LDO nanosheets. Further, when the mass ratio of Co(NO3)(2)center dot 6H(2)O/LDH was 1:1.8 and the calcination temperature was 550 degrees C, the ZnFe-LDO/Co3O4 composite exhibited 93.3% degradation efficiency for methylene blue (MB) at the applied voltage of 1.0 V under visible light after 3 h. Furthermore, the Mott -Schottky model experiments showed that the formation of a p-n heterojunction between ZnFe-LDO and Co3O4 could effectively inhibit the recombination of electrons and holes in the photoelectrocatalytic process. Meanwhile, free radical scavenging experiments showed that the active radicals of ,OH played an important role in the degradation of MB. Therefore, the photoelectrocatalytic effect of ZnFe-LDO/ Co(3)O(4 )provides a simple and effective strategy for the removal of organic pollutants. (C) 2022 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.