Synthesis of ZnO and ZnS nanoparticles and their structural, optical, and photocatalytic properties synthesized via the wet chemical method

Abstract

This study reports the synthesis of ZnO and ZnS and their nanocomposites with varying ratios of the two by the wet chemical method. The successful preparation of the samples was confirmed from XRD, FESEM, Raman spectroscopy, and EDX analysis showed hexagonal wurtzite phase of ZnO, cubic ZnS crystal structure, with high purity and crystallinity, coupled with nanoparticles-like morphology of the samples. The optical study reveals that the bandgap of ZnO, ZnS, and their composites, GT-1, and GT-2, was 3.23, 3.54, 3.31, and 3.36 eV, which decreases the bandgap energy after recombination of ZnO and ZnS. The photoluminescence spectral analysis demonstrates that multiple separate bands drive the broad emissions spectrum with zinc vacancies, oxygen vacancies, and surface imperfections. The photocatalytic performance of these samples was tested for degradation of a dye methylene blue under UV light exposure. Among different samples, the GT-1 composite shows a higher dye degradation efficiency (93%) than pure ZnO (55%).