Rapid removal and decomposition of gaseous acetaldehyde by the thermo- and photo-catalysis of gold nanoparticle-loaded anatase titanium(IV) oxide

Abstract

Gold nanoparticles (NPs) with a mean particle size ranging from 2.1 to 7.4nm were loaded on anatase TiO2 particles (Au/TiO2) by the heating temperature-varied deposition precipitation technique. This study has shown that Au/TiO2 with Au particle size <3nm and TiO2 surface area >50m2g−1 can be a promising environmental catalyst for the rapid removal and decomposition of gaseous acetaldehyde in a closed space. The Au loading on TiO2 causes a drastic enhancement of the acetaldehyde adsorption in the dark, and the adsorption amount increases as the Au particle size decreases. This result originates from the thermocatalytic activity of Au/TiO2 for the oxidation of acetaldehyde to acetic acid under ambient conditions. The resulting acetic acid spontaneously moves to the TiO2 surface due to the great adsorptivity for the carboxyl group. Consequently, the acetaldehyde adsorption amount strongly depends on the TiO2 surface area in addition to the Au particle size. UV-light irradiation of acetaldehyde (or acetate)-adsorbed Au/TiO2 leads to the complete decomposition to carbon dioxide by the high photocatalytic activity of anatase TiO2.