Method for preparing silver-carrying nano titanic oxide

Abstract

The present invention provides a method for preparing a nano silver-carrying titanium dioxide antiseptic. The aqueous ammonia solution and silver nitrate solution are dropped into the titanium sulfate solution simultaneously with continuous stirring. The final reaction pH is controlled by ammonia water. The titanium and silver are leaded to coprecipitate. The solution is filtered and washed after maturing. Afterwards the powder of nano silver-carrying titanium dioxide antiseptic is prepared by drying and calcining. The titanic acid or metatitanic can also be taken as precursor. The slurry containing 15-25% of recursor is added with silver nitrate solution with a concentration of 20-30gL<-1>, and the phosphoric acid, sulfuric acid or hydrochloric acid is added with a concentration of 10-15mgL<-1>. The solution is reacted, filtered and washed under the temperature of 50-60 DEG C. The solid object is dried, crushed, calcined and cooled, and the power of nano silver-carrying titanium dioxide antiseptic is obtained. The invention uses generating an indissoluble silver salt with a preparing technique of titanium dioxide to obtain the sustained-releasing of silver and color changing prevention. Furthermore the complex of the electron pair and the cavity is avoided. The photocatalysis antimicrobial effect of titanium dioxide is reinforced. The color, luster, granularity and dispersibility of the product can be well controlled.

Description

[technical field] [0001] The invention belongs to the field of environmental materials, and relates to a method for preparing a silver-loaded nano-titanium dioxide antibacterial agent. [Background technique] [0002] Titanium dioxide photocatalytic antibacterial agent and silver-based antibacterial agent are both inorganic antibacterial agents, which have the characteristics of safety, durability and wide application, and have been widely used in recent years. But the bandgap width of anatase titanium dioxide (E g ) is 3.2eV, only when there is light irradiation with energy greater than its forbidden band width and wavelength less than 387.5nm, the electrons on the valence band can be excited into the conduction band to form negatively charged highly active electrons e - and generate a corresponding hole h in the valence band + , electrons and holes are separated and migrated to different positions on the particle surface, oxidizing and reducing harmful substances adsorbed...

AI Technical Summary

Problems solved by technology

Therefore, the titanium dioxide photocatalytic antibacterial agent needs to be sterilized in the presence of ultraviolet light, and the excited free electrons are easy to recombine with holes, making the bactericidal effect unsatisfactory.

Silver-based antibacterial agents are antibacterial agents that add silver ions to carriers such as zeolite, phosphate, and soluble glass. This silver-ion antibacterial agent prepared by ion exchange requires a higher silver ion content, and the initial release of silver ions makes it less effective in the later stage. The slow-release performance is not good, and silver ions are easy to precipitate and change color under high temperature or oxidative atmosphere