Study the structure and performance of thermal/plasma modified Au nanoparticle-doped TiO2 photocatalyst

Abstract

This study describes the influence of thermal/plasma treatments on the structure and photocatalytic performance of the Au -doped TiO 2 catalyst. Au (gold) nanoparticles were attached on TiO 2 (Titania) nanoparticle surfaces by conventional deposition precipitation technique and the resulting catalysts were subsequently modified with thermal (at 450°C under vacuum) and plasma (at an ambient temperature under Argon atmosphere for 20 min) treatments. Structural characterization of the modified catalysts was performed by diverse analytical techniques and the photocatalytic activity was evaluated by assessing the degradation of the methylene blue (MB) in water under UV (ultra-violet) irradiations. Results showed that the thermal/plasma treatment significantly influenced the structural features of Au -doped TiO 2 catalyst by altering the morphology, increasing the Au nanoparticles population, improving the Au / TiO 2 catalytic activity, changing the textural properties and reducing the band gap energies thus tuned Au -doped TiO 2 catalyst to higher efficiency. Thermal/plasma treated Au -doped TiO 2 was found to exhibit higher photocatalytic activity than the as-synthesized (pristine sample). This improvement in photocatalytic activity might be due to the cathodic influence of gold in suppressing the electron–hole recombination during the reaction.