Effect of the amapa-latex chelating agent contents on the microstructure and photocatalytic properties of ZnO nanoparticles

Herein, we have explored the defects-driven photocatalytic properties of ZnO nanoparticles synthesized using different sweet Amapa-latex contents as natural chelating agents. XRD, SAED, and FTIR analyses confirmed the formation of single-phase ZnO nanoparticles. TEM analysis showed nanoparticles with strong polycrystalline nature and average particle size ranging from 14.1 to 16.5 nm, with the smaller particle size (ZnO#10) exhibiting a larger surface area. The pentacyclic triterpenes present in Amapa-latex chelating agents play a critical role in the complexation of Zn2+ ions and the formation of pure ZnO nanostructures. The broad photoluminescence spectra revealed several structural defects in the nanoparticles, particularly, V-Zn, V-O(++), O-i(+), and Zn-O were widely observed for the sample synthesized using 10 mL of Amapa-latex (ZnO#10). A 99.47% visible-light-mediated discoloration of the aqueous methylene blue dye solution containing ZnO#10 nanoparticles was mainly ascribed to the continuous production of hydroxyl radicals by the defective structure of this sample. Furthermore, a similar to 30% TOC removal was observed after the 5th cycle of reuse of ZnO#10 nanoparticles, proving that the production of reactive species cleaves and breaks down MB dye molecules. Thus, the sweet Amapa-latex proved to be an effective chelating agent for obtaining ZnO nanoparticles with singular optical-structural characteristics that can be useful for treating dye-contaminated textile effluents. (c) 2022 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).