Plasma catalysis application of gold nanoparticles for acetaldehyde decomposition

•Different sizes of gold nanoparticles were obtained by photocatalytic reduction.•Au/TiO2 is suitable catalyst for acetaldehyde removal in term of energy yield.•Plasma treatment doesn’t influence the surface Au atoms density.•The reaction mechanism of acetaldehyde decomposition by Au/TiO2 was proposed. The decomposition of acetaldehyde was investigated in a plasma-catalytic reactor. The gold-based catalysts were obtained by growing Au nanoparticles on silica beads or plates previously coated by a titanium oxo-alkoxy monolayer. The characterization of the synthesized catalysts was carried out by SEM, AFM and UV–Visible spectroscopy. Below an exposure time to UV of 20 min, a homogeneous surface coverage by the relatively small gold nanoparticle (R