Silver Nanowire/Titanium Dioxide Preparation Of Composite Materials And Research On Their Optical Properties

Water pollution has become one of the environmental crises that affect human health and restrict sustainable economic development.Titanium dioxide?TiO₂?,as an excellent ultraviolet photocatalytic material,can effectively remove pollutant dyes in sewage,but generally can only be excited under ultraviolet light to use 5%of sunlight.Therefore,improving the photocatalytic efficiency under sunlight can effectively reduce the degradation cost.At the same time,due to the serious water pollution and the low concentration of pollutants such as general drugs in the water body,it is urgent to research and develop on-site rapid analysis and detection techniques,such as surface enhanced Raman spectroscopy?SERS?with high detection sensitivity,stable development performance and strong applicability The high sensitivity of the substrate is the key to practical application.In this thesis,the effect of the connection between the interface between the silver nanowire?Ag NW?and the TiO₂ composite material is obtained to obtain the law of the surface-enhanced Raman spectroscopy signal.Application to the detection of trace pollutants in water.Starting from the preparation of Ag NWs and TiO₂ composite materials,the forbidden band width of TiO₂ semiconductors is adjusted to widen the wavelength range of light response and promote the separation of photogenerated carriers,thereby improving the photocatalytic efficiency.Two types of Ag NWs/TiO₂composite materials were prepared using chemical and physical methods.The prepared core-shell structure performance is stable and the base film is uniform.Using the organic dye Rhodamine B as the target degradation product,Ag NW@TiO₂ core-shell composite photocatalysts with different loading ratios were prepared by hydrothermal method,and their visible light catalytic activities were evaluated.The results show that the core-shell structure is Ag NWs and anatase TiO₂ after calcination,and the band gap of TiO₂ can be reduced to achieve excitation in the visible light range.By loading an accurate amount of TiO₂,the best degradation effect can be achieved.Different loadings can make the thickness of TiO₂ shell on Ag NW@TiO₂ core-shell structure surface different.Adding 400 uL of Ag NW@TiO₂ under TBOT load can form a single-layer TiO₂ shell to coat Ag NWs.That is,when the molar ratio of TiO₂ to Ag NWs is 84%,the combination of the two plays the best photocatalytic degradation effect,and the degradation rate of rhodamine B can reach 82.2%.The main active oxide is superoxide radical.The structure has strong stability,and no oxidation or phase transition occurs after 263 days.By studying different mechanical mixing methods and adjusting the pH,four different substrate materials were prepared,and the prepared substrates were evenly loaded,of which J2.5 had the best loading effect on the silver wire.Using R6G as the target test substance,the SERS sensitivity of the molecule was tested,and finally it was found that the rhodamine 6G trace detection showed good surface enhanced Raman spectroscopy performance,the detection limits were 10^-6 mol/L The weak laser irradiation treatment at room temperature improves its sensitivity,and the Raman peak intensity for R6G detection is increased by 4 orders of magnitude.