COPPER AND SULFUR CO-DOPED ZNO NANOPARTICLES FOR EFFICIENT SOLAR PHOTOCATALYTIC DEGRADATION OF METHYL ORANGE

In the present study pure ZnO nanoparticles were prepared using a co-precipitation technique. As-prepared ZnO, was used to prepare Cu-doped ZnO, S-doped ZnO, and Cu & S co-doped ZnO nanostructures by simple hydrothermal method. The synthesized materials were characterized employing XRD, FTIR, and UV-visible spectroscopic techniques. The crystallite particle size of pure ZnO (45.7 nm), was highest among the synthesized powders followed by Cu-doped ZnO (43.29 nm), S-doped ZnO (43.4 nm), and Cu & S co-co-doped ZnO (43.19 nm). The UV-visible absorption spectra of aqueous dispersion of synthesized powders revealed that doping Cu and S in ZnO, both contributed synergistically to lowering of band gap energy from 3.27 eV to 2.35 eV. The photocatalytic efficacies of as-synthesized powders under solar irradiation were determined in terms of methyl orange degradation, as a probe. The observed highest photocatalytic degradation (85 %) of 25 mg L-1 dye in aqueous solution within 60 minutes using Cu & S co-doped ZnO load 1.5 gL-1 can be attributed to the lower rate of photo-generated charge carriers’ recombination as well as lowering of band gap energy enabling absorption of more photons in the visible range of solar radiation. Considering the high photocatalytic efficiency of newly synthesized Cu and S co-doped ZnO powder, the same may be recommended for an effective treatment of methyl orange-contaminated wastewater.