On the Role of Plasmonic Nanoparticles on the Photocatalytic of TiO₂ Nanoparticles for Visible-Light Photoreduction of Bicarbonate

The potential application of anatase titanium dioxide (TiO₂) nanoparticles for solar fuel generation has been recently attracting many attentions due to its excellent chemical stability. Nevertheless, the fast charge recombination during photoexcitation process may often reduce the photocatalytic activity. This work presents the role of plasmonic Au nanoparticles on enhancing the photocatalytic activity of TiO₂ nanoparticles for a visible-light-driven conversion of bicarbonate to formate. Here, two types of nano-sized Au and TiO₂ heterostructures, i.e., Au-TiO₂ Janus nanostructures and core-shell Au@TiO₂ nanostructures were successfully prepared and characterized using UV-Vis and HR-TEM. Results demonstrated that Au-TiO₂ Janus nanostructures had a superior photocatalytic activity compared to TiO₂ nanoparticles and core-shell Au@TiO₂ nanostructures. This photocatalytic enhancement is believed due to the presence of surface plasmon resonance (SPR) phenomenon in Au nanoparticles that provides a Fermi energy level, which could prevent the charge recombination process during photoexcitation.