Study of innovative photocatalytic cement based coatings: The effect of supporting materials

Abstract

For an ideal photocatalytic active building material, the substrate, on which the photocatalytic material is deposited, should neither interfere with nor affect its photocatalytic activity. In the present work, photocatalytic cement based coatings were immobilized on the surface of three different building substrates: gypsum, plywood and glass. The purpose was to investigate the effect of the substrates material on the photocatalytic activity of the corresponding end products against NO. In addition, the effect of the coatings composition and the selected illumination source (UV & Vis) on the material’s photocatalytic behavior was also studied. Results displayed a slightly higher photocatalytic activity for the cementitious coatings on the glass substrate compared to the ones obtained on gypsum and plywood substrates, Overall, both cement based coatings, with 5% w/w and 10% w/w photocatalyst (Mn doped TiO2), presented sufficient photocatalytic activity under either UV or Vis irradiation in the NO abatement. The latter (10% w/w) exhibited, as expected, a slightly better performance due to higher concentration, as monitored by the corresponding photocatalytic degradation rate parameters (n% and r) value.