Synthesis And Characteristic Of Noble Metal Nanoparticles Based On Hydrogen Nanobubbles

The nanoscale bubbles in liquid phase were some cavities which could contain and dissolve gases. The addition of surfactants could obviously promote the stability of the nanobubbles. The gas in liquid phase could enter to the interior of the bubbles and also could dissolve out of the bubbles. Nanobubble has several compelling factors contributing to its exceptional ability to contain gas:the wide surface area, longlifespan, and a pressurized interior gas due to surface tension. In particular, the nanoscale bubbles could be stable in the system for long time. This is because they reling on shadow effect effectively and produced a pressure of gas from nearby bubbles that may be separated by about the thickness of the non-disturbance layer. Gas diffused from the nanobubbles can be used as a slow-release reactant for the specific reaction.In this paper, we prepared H2 nanobubbles gas-liquid dispersion system using the pump intake return flow pressure dissolved gas release method. Using nanoparticles tracking technology (NTA), Zeta potential analytical technique, ATR-FTIR, Redox potential analytical technique to characterize the basic properties of H2 nanobubbles and the mechanism of its structure and stability.Used H2 nanobubbles dispersed system as a reducing agent and controlled the concentration ratio of the metal source and surfactants, the aging temperature, the type of the surfactants to prepare metal nanoparticles with different shape and good monodispersity. After experiment, we got the following conclusion:(1) Nanobubbles gas-liquid dispersion system contains dissolved and dispersed gas. The existence of nano bubbles can increase greatly the content of gases. Gas diffused from the nanobubbles can be used as a slow-release reactant for the specific reaction.(2) We prepared the gas-liquid dispersion system which contained two sizes of the H2 nanobubbles and the relations between the two diameter is multiple. The addition of surfactant greatly improved the stability of H2 nanobubbles and the magnitude of nanobubbles concentration is 108/mL.(3)The sodium polyacrylate molecules adsorbed on the gas-liquid interface when produced H2 nanobubbles gas-liquid dispersion system. The hydrophobic groups trended to the interior of the bubble and the hydrophilic group trended to external liquid. As a result, hydrogen bonds hanged liked a cage structure. ATR-FTIR proved this supposition.(4) The Redox potential value of the H2 nanobubbles gas-liquid dispersions was low, so it could be used as a reducing agent of certain reaction. In this experiment, different kinds of metal sources were added to the solution. The metal ions adsorption on the surface of nanobubbles and were reduced into different morphology nanoparticles by the H2 slow-released from the nanobubbles. NTA technology, Zeta potential analytical technique ect were used in our paper.(5)The experiment conditions to prepare different morphology of metal nanoparticles should be optimized when using chitosan as the surfactant and H2 nanobubbles gas-liquid dispersion system as a reducing agent.