Ascorbic acid mediated synthesis of highly porous ZnO microsphere for sustainable hydrogen generation and efficient methylene blue dye degradation

• Published in: Journal of materials science. Materials in electronics 2024-10, Vol.35 (28), p.1863, Article 1863
• Main Authors: Khade, Mayuri, Padwal, Yogita, Waghadkar, Yogesh, Chauhan, Ratna, Fouad, Hassan, Gosavi, Suresh W.
• Format: Article
• Language: English
• Subjects: Absorption spectra; Ascorbic acid; Characterization and Evaluation of Materials; Chemical synthesis; Chemistry and Materials Science; Dyes; Electromagnetic absorption; Excitons; Hydrogen evolution; Hydrogen production; Materials Science; Methylene blue; Nanomaterials; Nanoparticles; Optical and Electronic Materials; Photocatalysis; Photodegradation; Synergistic effect; X-ray diffraction; Zinc acetate; Zinc oxide; Zinc oxides
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-024-13537-w

This study involved the successful synthesis of hollow spherical zinc oxide (ZnO) microsphere through a Solvothermal method, utilizing a 0.1 M zinc acetate and 0.1 M ascorbic acid solution with three different reaction durations: 6 h, 12 h, 24 h, 36 h and 48 h. The study employed a characterization technique, including X-ray diffraction (XRD), UV-Visible and FESEM, to investigate the structural, optical, and morphological characteristics of ZnO. XRD shows a pure hexagonal ZnO phase, affirming the high purity of the nanomaterial, with no detectable impurities. Notably, ZnO nanoparticles exhibited a widened absorption spectrum from 200 to 400 nm, attributed to light scattering effects caused by the secondary one-dimensional (1-D) nanostructures present on the surfaces of pomegranate-like microsphere shells. This property holds substantial promise for potential applications in visible light-driven photocatalysis. The practical application of these ZnO nanoparticles was assessed by conducting sunlight-driven catalytic experiments for the hydrogen generation and degradation of methylene blue (MB), a common dye pollutant. Notably, ZnO nanoparticles synthesized over 12 h exhibited remarkable results in the photocatalytic performance as compared to those synthesized over 6 h, 24 h, 36 h and 48 h. The maximum hydrogen evolution rate and MB dye degradation efficiency with ZnO microsphere is 980 μmol/h/g and 97% within 40 min, respectively. This improvement in photocatalytic performance can be accredited to synergistic effects arising from the combination of ZnO nanoparticles synthesized at different time intervals, leading to improved visible light absorption and a decrease in the recombination rate of exciton (e − /h + ).