Photocatalytic Degradation of Rose Bengal Dye using Chemically Synthesized Pristine and Molybdenum doped Zinc Oxide

Vishal Kadam1

Chaitali Jagtap1

Vilas Kumkale1

Udayabhaskar Rednam2

Prasad Lokhande1,2,Email

Habib Pathan1,Email

1Advanced Physics Laboratory, Department of Physics, Savitribai Pule Pune University, Pune 411007, India.
2Departamento de Mecánica, Facultad de Ingeniería, Universidad Tecnológica Metropolitana, Santiago 8330383, Chile.

Abstract

In this study, pure zinc oxide (ZnO) and Molybdenum (Mo) doped zinc oxide (Mo: ZnO) nanoparticles with 5 and 10% wt% doping were synthesized via a simple reflux chemical process. Various characterization techniques were used to examine the structural, morphological, optical, and photocatalytic properties of the synthesized samples. The XRD data demonstrated that the crystallite size of ZnO decreased as the concentration of Mo-doping increased. SEM characterization was used to study the morphology of the samples, which showed irregular spherical nanoparticles for the pure ZnO while addition of the Mo dopants the shape became homogeneous. The e-mapping and the EDX results confirm the presence of Zn, O, and Mo elements. The absorption spectrum (UV–Vis) showed that when Mo dopants are incorporated into ZnO, the absorption is increased along with the band gap. The band gap values for ZnO ranged between 2.9 - 3.14 eV with a Mo doping concentration between 0 - 10 wt%. Mo-doped zinc oxide samples demonstrated a higher level of activity than bare zinc oxide, with 5% Mo-doped zinc exhibiting a decrease in the colour of 91%. Furthermore, the addition of 10% Mo to the zinc oxide lattice increased activity, with 79% of the dye's colour being discharged after 30 minutes. The highest activity was achieved when 5% Mo was added to the zinc oxide sample, resulting in a decrease in the dye's colour of 91%. The half-life is observed to be minimum for 5% Mo: ZnO 5.28 mm-1. The sample with the highest rate constant was 5 wt% Mo, which had a rate constant that was 2x higher than the rate constant of bare ZnO. 

Photocatalytic Degradation of Rose Bengal Dye using Chemically Synthesized Pristine and Molybdenum doped Zinc Oxide