Preparation method of black titanium dioxide nano thin film

Abstract

The invention belongs to the technical field of preparation of nano thin films and relates to a preparation method of a black titanium dioxide nano thin film. A technological process comprises three steps including preparation of nanoparticles, preparation of the nano thin film and thickness control of the nano thin film; black titanium dioxide nanoparticles are prepared from titanium tetraisopropoxide and nickel nitrate; the black titanium dioxide nanoparticles are deposited on a stainless steel substrate by adopting an electrophoretic deposition method so as to prepare the black titanium dioxide nano thin film; nickel ion doping is coupled with hydrogen atmosphere heat treatment modification, and effective active sites can be formed on the surface of titanium dioxide by doping nickel ions, and separation of photo-induced electrons and holes is accelerated; the catalytic activity of the titanium dioxide is improved and hydrogen atmosphere heat treatment can expand a photo-response region of the titanium dioxide; white titanium dioxide is turned into black titanium dioxide; the technological process is simple, low in production cost, rapid in deposition speed and high in film-forming quality; an application environment is environmentally friendly and commercialized requirements are met.

Description

[0001] Technical field: [0002] The invention belongs to the technical field of nano-film preparation, and relates to a method for preparing a black titanium dioxide nano-film. A black titanium dioxide nano-film doped with nickel is prepared by an electrophoretic deposition method with simple operation device, low cost, high film-forming quality and fast deposition rate. [0003] Background technique: [0004] Titanium dioxide (TiO 2 ) is a white solid or powdery amphoteric oxide with a relative molecular mass of 79.83. As a semiconductor material, titanium dioxide has the characteristics of low price, simple preparation and good chemical stability. It is usually used as a catalyst for light paint pigments to degrade pollutants It is not only an environmentally safe cleaning agent, but also can save energy and protect environmental resources; at present, titanium dioxide photocatalyst has been widely used in the fields of air purification and water treatment, and the basic pri...

AI Technical Summary

Problems solved by technology

Nano-film refers to a film material formed by embedding components on the order of 1-100nm in a matrix, which has the advantages of both traditional composite materials and modern nano-materials; in the prior art, the methods for preparing titanium dioxide nano-films mainly include Sol-gel method, anodic oxidation method and chemical vapor phase direct deposition method, among which sol-gel method, referred to as S-G method, uses organic or inorganic salt as raw material, carries out hydrolysis and polycondensation reaction in organic medium, and makes the solution undergo The sol-gel process obtains a gel, and the gel is heated or freeze-dried and calcined to obtain titanium dioxide nanoparticles. The titanium dioxide nanoparticle powder obtained by this method is uniform, good in dispersibility, high in purity, low in calcination temperature, and easy to control the reaction. There are few side reactions and simple process operation, but the cost of raw materials is high, and it is not easy to popularize and use; the anodic oxidation method is an electrochemical reaction process carried out under the condition of high voltage, and the anodic oxidation process takes tens of minutes or even longer. Low efficiency; direct chemical vapor deposition (CVD) is a method that uses the vapor of volatile metal compounds to generate the desired compound through chemical reaction. The titanium dioxide nanoparticles prepared by this method have fine particle size, high chemical activity, spherical particles and monodisperse Good permeability, good visible light permeability, strong ability to absorb and shield ultraviolet rays, simple and easy to operate, low cost, low requirements for equipment and technology, but it is difficult to precipitate and wash, titanium dioxide nanoparticles contain impurities, and the particle distribution is wide. Limited scope of application

In the prior art, the bandgap width of white titanium dioxide is 3.2eV, which can only absorb ultraviolet light accounting for 5% of the solar spectrum, and cannot fully utilize visible light. The separation efficiency of photogenerated electrons and holes in white titanium dioxide is low, which is not conducive to Charge transport to the catalyst surface for chemical reactions, limited light absorption and low charge separation efficiency limit the improvement of photocatalytic activity

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