Plasma Enhanced Wet Chemical Surface Activation of TiO2 for the Synthesis of High Performance Photocatalytic Au/TiO2 Nanocomposites

Improvement of the Photocatalytic Activity of Au/TiO2 Nanocomposites by Prior Treatment of TiO2 with Microplasma in an NH3 and H2O2 Solution

Plasmonic photocatalytic nanocomposites of TiO2 and Au nanoparticles (NPs) have recently attracted the attention of researchers, who aim to improve the photocatalytic activity of potential TiO2 NPs. In this study, we report photocatalytic activity enhancement for a Au/TiO2 nanocomposite prepared by the plasma–liquid interaction method using an atmospheric microplasma apparatus. The enhanced photocatalytic activity of the prepared Au/TiO2 is demonstrated by the degradation of methylene blue (MB) in water under both ultraviolet (UV) and visible light irradiation. The prior treatment of TiO2 with microplasma in a NH3 and H2O2 solution is found to strongly improve the photocatalytic activity of both the treated TiO2 NPs, as well as the synthesized Au/TiO2 nanocomposite.

Au nanoparticle-decorated TiO2 hollow fibers with enhanced visible-light photocatalytic activity toward dye degradation

TiO₂ hollow fibers (THF) were prepared by a template method using kapok as a biotemplate and subsequently decorated by plasmonic Au nanoparticles using a solution plasma process. The THF exhibited an anatase phase and a hollow structure with a mesoporous wall. Au nanoparticles with a diameter of about 5–10 nm were uniformly distributed on the THF surface. Au nanoparticles-decorated TiO₂ hollow fibers (Au/THF) have enhanced photocatalytic activity toward methylene blue degradation under visible light-emitting diode (Vis-LED) as compared to pristine THF and P25. This could be attributed to combined effects including effective light-harvesting by a hollow structure, large surface area due to a mesoporous wall of THF, and visible-light absorption and efficient charge separation induced by Au nanoparticles. The Au/THF also showed good recyclability and separation ability.

Plasmonic Au nanoparticles-decorated TiO₂ hollow fibers with enhanced visible-light photocatalytic activity have been successfully prepared by a two-step process: (i) template method using kapok and (ii) solution plasma process.