Plasmonic effect of metal nanoparticles on the photocatalytic properties of TiO₂/rGO composite

A comparative study of the plasmon effect of Ag and Au nanoparticles on TiO₂/rGO nanocomposite was carried out. The synthesis of Au and Ag nanoparticles was carried out by laser ablation. The morphology and structure of the nanocomposites were studied by EDA, HRTEM, XRD and Raman spectroscopy. It was shown that the absorption capacity of the nanocomposite material was increased in the visible range of the spectrum when Ag and Au nanoparticles were added to TiO₂/rGO. This leads to an increase in their photocatalytic activity. The photocurrent generated by NC/Au 10⁻¹¹ films is in 3.8 times and NC/Ag 10⁻¹² is in 2 times higher compared to pure TiO₂/rGO film. Similar results were obtained from experimental data on the dyes photodegradation. In the presence of plasmon nanoparticles a significant enhancement in the electrical properties of the TiO₂/rGO nanocomposite was recorded. The charge carrier transfer resistance in nanocomposites was decreased by almost ∼7 times for NC/Au,10⁻¹¹ and ∼4 times for NC/Ag,10⁻¹² films compared to pure TiO₂/rGO. In addition, for nanocomposites with Ag or Au nanoparticles, a decrease in the effective electron lifetime was observed. The data obtained allow us to conclude that plasmonic NPs have a synergistic effect in TiO₂/rGO nanocomposites, which consists in modifying both their light-harvesting properties and charge-transport characteristics. The results obtained can be used for the design of materials with improved photocatalytic and optoelectronic characteristics.