The Preparation And Optical Properties Of TiO₂/Au Core-shell Nanocomposites

Recently,a large effort has been made to advance light-based technologies through precise control the employed materials. Nanocomposites have been employed in various fields, including defense industries, energy development, environmental science, bio-medical, food safety, and so on. The optical properties of the core-shell nanomaterials is controlled, which has aroused widespread interest. Localized surface plasmon resonance absorption of Au shell can be adjusted from the visible to near-infrared wavelength region, the unique feature of plasma absorption has been used for a variety of applications, including sensing, surface-enhanced Raman spectroscopy(SERS), imaging and photothermal conversion. Ti O2 has attracted considerable attention in the area of sustainable energy and environmental remediation due to its unique optical properties, photoelectric properties, biocompatibility, and chemical stability.This paper is mainly study the optical properties of Ti O2/Au semiconductor/noble metal core-shell nanocomposites. The main content consists of two parts:(1) Ti O2 / Au core-shell hybrid materials are prepared. Mixed with glycols and titanium alkoixde were reactive to form glycolates derivative precursor solution, when spherical colloids of titanium glycolated were obtained in acetone. By annealing at 500℃ or hot water treatment to obtain a good monodispersity, spherical colloidal of anatase crystal phase Ti O2 particles. Particularly, the mesoporous surface of titanium can be formed after hot water treatment(m Ti O2). Next APTMS-modified the surface of titanium spherical particles, following 1-5nm gold nanoparticles were absorbed forming the seed, finally the gold shell structure was reduced at the surface growth sites of Ti O2, the different plasma resonance absorption by controlling synthetic of the material experiment. Laser particle analyzer, XRD, SEM, TEM, UV-Vis absorbance spectra, Mapping, EDX and other equipment were employed for characterization of the materials systematically.(2) By annealing at 500℃ or hot water treatment to obtain two kinds of Ti O2 particles, which were coated with Au shell synthesized Ti O2/Au and m Ti O2/Au core-shell nanocomposites. Their optical properties of materials were explored. P-ATP was used for SERS detection molecule, SERS of different substrate materials were compared under the same conditions. Under the visible and ultraviolet irradiation, photocatalytic degradation of Rhodamine B were explored. m Ti O2/Au presented visible-light-active catalytic efficiency and can improve the ultraviolet light catalytic efficiency.The calcined crystalline Ti O2 coating Au shell didn’t present catalytic efficiency. The reason has been discussed in detail. The Ti O2 crystalline calcined microspheres was coated with Au, which plasma absorption peak at about 800 nm. The temperature changes were recorded during 808 nm laser irradiation. at The elevated temperature up to about 30℃ was achieved successfully in 10 minutes.