Title: Reduction of the photocatalytic activity of ZnO nanoparticles for UV protection applications

Authors: Takuya Tsuzuki; Rongliang He; Jinfeng Wang; Lu Sun; Xungai Wang; Rosalie Hocking

Addresses: Institute for Technology Research and Innovation, Deakin University, Geelong Technology Precinct, Geelong, VIC 3217, Australia ' Institute for Technology Research and Innovation, Deakin University, Geelong Technology Precinct, Geelong, VIC 3217, Australia ' Institute for Technology Research and Innovation, Deakin University, Geelong Technology Precinct, Geelong, VIC 3217, Australia ' Institute for Technology Research and Innovation, Deakin University, Geelong Technology Precinct, Geelong, VIC 3217, Australia ' Institute for Technology Research and Innovation, Deakin University, Geelong Technology Precinct, Geelong, VIC 3217, Australia ' Monash Centre for Synchrotron Science and School of Chemistry, Monash University, Clayton, VIC 3800, Australia

Abstract: The detrimental effects of UV radiation are having a significant impact on our life and environment. The development of effective UV shielding agents is therefore of great importance to our society. ZnO nanoparticles are considered to be one of the most effective UV blocking agents. However, the development of ZnO-based UV shielding products is currently hindered due to the adverse effects of the inherent photocatalytic activity exhibited by ZnO. This paper reports our recent study on the possibility of reducing the photoactivity of ZnO nanoparticles via surface modification and impurity doping. It was found that the photoactivity was drastically reduced by SiO₂-coatings that were applied to ZnO quantum dots using the Stöber method and a microemulsion technique. The effect of transition metal doping on the photoactivity was also studied using mechanochemical processing and a co-precipitation method. Cobalt doping reduced the photoactivity, while manganese doping led to mixed results, possibly due to the difference in the location of dopant ions derived from the difference in the synthesis methods.

Keywords: UV protection; ZnO nanoparticles; photocatalytic activity; transition metal doping; surface modification; nanotechnology; ultraviolet radiation; zinc oxide; photocatalysis; UV radiation; UV blocking agents; UV shielding products; quantum dots; cobalt; manganese; silica; silicon dioxide.

DOI: 10.1504/IJNT.2012.049463

International Journal of Nanotechnology, 2012 Vol.9 No.10/11/12, pp.1017 - 1029

Published online: 04 Oct 2012 *

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