Enhanced Sunlight Photocatalytic Performance of Hafnium Doped ZnO Nanoparticles for Methylene Blue Degradation

Abstract

A series of Hf-doped ZnO nanocatalysts were synthesized by sol–gel method with a doping content up to 6 mol%. The structure, morphologies, and optical properties of the synthesized catalysts were characterized by XRD, TEM, FTIR and UV–Vis absorption spectrometer. The photocatalytic activity was evaluated by the Methylene Blue degradation in aqueous solution under sun light irradiation. Irradiation time and doping content had important effects on the photocatalytic activity of Hf-doped ZnO. Hafnium content had an optimum value of 2 mol% for achieving high photocatalytic activity. The experiments demonstrated that MB was effectively degraded up to 85% within 120 minutes. It was confirmed that the presence of Hafnium in ZnO catalysts could enhance the photocatalytic oxidation.

Keywords:

• Nanocrystalline ZnO
• sol-gel synthesis
• Hf-doped ZnO
• photocatalysis

Acknowledgments

M. Ahmad is gratefully acknowledged the financial support by Higher Education Commission, Pakistan. This work was supported partially by Natural Science Foundation of China (No. 51072180), China Postdoctoral Science Foundation (No. 20110491764) and the State Key Laboratory of Silicon Materials (SKL2009-14) at Zhejiang University.