Photocatalytic Degradation of Rose Bengal Dye using Chemically Synthesized Pristine and Molybdenum doped Zinc Oxide
Abstract
In this comprehensive study, the synthesis of pure zinc oxide (ZnO) nanoparticles and their molybdenum-doped counterparts (Mo: ZnO) was meticulously carried out through a refined reflux chemical process. The doping concentrations were carefully controlled at 5 and 10% wt%, aiming to investigate the impact on the nanoparticles' properties. A suite of characterization techniques was employed to delve into the structural, morphological, optical, and photocatalytic nuances of the synthesized materials. The crystalline nature and particle size variations were revealed through X-ray diffraction (XRD) analysis, which indicated a discernible decrease in ZnO crystallite size with an increase in Mo doping levels. Scanning electron microscopy (SEM) provided insights into the morphology, displaying a transition from irregular spherical shapes in pure ZnO to a more uniform morphology upon Mo incorporation. Elemental mapping and energy-dispersive X-ray spectroscopy (EDX) analyses corroborated the elemental composition, confirming the integration of Zn, O, and Mo within the samples. Optical properties were probed using UV-Visible spectroscopy, which demonstrated an enhancement in absorption capabilities and modulation of the band gap as a function of Mo doping; the band gap narrowed progressively from 2.9 to 3.14 eV with increasing Mo content from 0 to 10 wt%. Photocatalytic performance was quantitatively assessed, revealing that Mo-doped ZnO nanoparticles exhibited superior activity compared to their undoped counterparts. Notably, the sample with 5% Mo doping achieved an impressive 91% decolorization of dye, signifying a potent photocatalytic effect. This heightened activity was further evidenced by a minimal half-life and a rate constant for the 5 wt% Mo-doped sample that was twice as high as that of pure ZnO, underscoring the significant enhancement brought forth by molybdenum doping.