Measurement of photocatalytic efficiency of nanoparticle ZnO and TiO2 for use in cement-based paint

• Grant number: 15/10716-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): August 01, 2015
• Effective date (End): April 30, 2016
• Field of knowledge: Engineering - Civil Engineering - Construction Industry
• Principal Investigator: Kai Loh
• Grantee: Giovana Nallin Davinha
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The proposed project aims to continue the research project FAPESP/Process 2013/06822-2 entitled "Study of the photocatalytic activity of nanoparticles (NPs) of ZnO compared to TiO2 applied on external surfaces of cementitious building." TiO2 particles are known to be effective for the purposes of self-cleaning external surfaces of buildings by incidence of ultraviolet radiation. This process occurs by the photocatalytic action of these particles degrading microorganisms and pollutants impregnated on the surface of buildings. In the project ZnO and TiO2 nanoparticles will be characterized in order to observe differences in the nanostructure, chemical and mineralogical composition of these two oxides. The photocatalytic activity will be evaluated by degradation of dyes such as methylene blue, methyl orange and/or methyl red, in solutions containing these oxides and exposure in a chamber under ultraviolet radiation (UV) incidence. The efficiency also will be observed in an accelerated exposure in chamber with UVA and UVB radiation on surfaces of painted and untreated specimens with artificial dirt with composition similar to semi-industrial cities air pollution. The exposure results in a natural environment, Process 2013/06822-2 in progress, will be correlated with the specimens prepared in the laboratory, to observe if the addition of ZnO can replace TiO2 in self-cleaning action when applied to building facades.