Nanoflower-like composites of ZnO/SiO2 synthesized using bamboo leaves ash as reusable photocatalyst

• Main Authors: Fatimah, Is, Fadillah, Ganjar, Sahroni, Imam, Kamari, Azlan, Sagadevan, Suresh, Doong, Ruey-An
• Format: Article
• Published: Elsevier 2021
• Subjects: QD Chemistry
• Online Access: http://eprints.um.edu.my/28435/
• Institution: Universiti Malaya

In this study, the synthesis of ZnO/SiO2 nanocomposites using bamboo leaf ash (BLA) and tested their photocatalytic activity for rhodamine B decolorization have been conducted. The nanocomposites were prepared by the sol-gel reaction of zinc acetate dihydrate, which was used as a zinc oxide precursor, with silica gel obtained from the caustic extraction of BLA. The effect of the Zn content (5, 10, and 20 wt%) on the physicochemical characteristics and photocatalytic activity of the nanocomposites was investigated. The results of X-ray diffraction, scanning electron microscopy, gas sorption, and transmission electron microscopy characterization confirmed the mesoporous structure of the composites containing nanoflower-like ZnO (wurtzite) nanoparticles of 10-30 nm in size dispersed on the silica support. Further, the nanocomposites were confirmed to be composed of ZnO/SiO2 by X-ray photoelectron spectroscopy analysis. Meanwhile, diffuse-reflectance UV-visible spectrophotometry analysis of the nanocomposites revealed band gap energies of 3.38-3.39 eV. Of the tested nanocomposites, that containing 10 wt% Zn exhibited the highest decolorization efficiency (99%) and fastest decolorization rate. In addition, the degradation efficiencies were not reduced significantly after five repeated runs, demonstrating the reusability of the nanocomposite catalysts. Therefore, the ZnO/SiO2 nanocomposite obtained from BLA is a promising reusable photocatalyst for the degradation of dye-polluted water. (C) 2020 The Author(s). Published by Elsevier B.V. on behalf of King Saud University.