The photocatalytic dye degradation of methylene blue (MB) by nanostructured ZnO under UV irradiation

Abstract Photocatalytic degradation failure is a significant environmental pollution problem. Therefore, this article emphasizes the in-depth photocatalytic degradation of methylene blue (MB) by UV light irradiation using ZnO photocatalysts nanoparticles every 30 min of a time interval and examines the improvement in the irradiation period. The sol-gel co-precipitation route produces the photocatalyst ZnO nanoparticle to eliminate MB dye. The characterization studies of ZnO photocatalysts are explored by x-ray diffraction, scanning electron, and UV visible spectroscopic techniques. The XRD study elucidates a lesser crystallite size of the order 24.71 nm with a small microstrain, and dislocation density boosts the ZnO nanoparticle to act as dilapidation of 10 ppm of MB colourant. The SEM photographs of Zinc oxide nanoparticles reveal the nanospeck dimension of 32 nm. The EDX and Elemental mapping explore the composition of the ZnO photocatalyst. The syntheses of ZnO nanoparticles have low overpotential for HER (Hydrogen Evolution Reaction). A very low slope of 41.2 mV/dec represents the Volmer-Tafel mechanistic pathway for the HER process. Chronopotentiometry was conducted, and the amount of hydrogen collected during these experiments was 21 ml for the ZnO nanoparticles.