Synthesis of ZnO photocatalyst via ZnO₂ precursor and its application for dye degradation from effluent under solar irradiation

Abstract

Nanosized ZnO crystallites were prepared by a new route from ZnO₂ as a precursor. In turn, the precursor was synthesized from Zn(CH₃COO)₂·2H₂O and H₂O₂ by a simple mechanochemical method. The synthesized photocatalysts was characterized by XRD, SEM, FTIR, and UV–visible spectroscopic methods. The X-ray diffraction data suggest that the synthesized ZnO crystallite has the hexagonal wurtzite structure with crystallite size ~13 nm. ZnO-mediated photocatalytic degradation of the dyes from an effluent has been investigated under solar irradiation. Experimental conditions for degradation of dyes including pH of the effluent, dose of the catalyst, and height of the effluent column in reaction vessel were optimized. Nearly 100% decolorization and more than 95% degradation of the dyes from the effluent were achieved under optimized conditions under solar irradiation within 90 min time.

Keywords:

• Degradation
• Solar irradiation
• Dyes
• Photocatalyst
• ZnO
• Effluent