Fabrication Of Building Coating For Degradation Of Indoor Air Pollutants

Along with the progress of industrialization in our country,people's living standards increase year by year.Today people also pay more and more attention to the living environment for their health.Actually the indoor air quality is directly related to people's health.For instance,formaldehyde,toluene is the most common indoor air pollutants.If a person long-term exposures to low doses of formaldehyde or toluene,he easy causes chronic respiratory disease,nasopharyngeal carcinoma,and even leukemia.In recent years,degradation of indoor air pollutants become popular in the multidisciplinary subject areas,because it receives extensive attention of people that reduce indoor air pollutants such as formaldehyde.Titanium dioxide belongs to a typical semiconductor material,and has high chemical stability,no pollution,low price,especially the ability which use the photoelectric characteristics to degrade organic pollutants,therefore,it is a kind of potential and promising photocatalyst.However,titanium dioxide has a larger band gap?3.2 eV?,as a consequence,they limit the wide use that titanium dioxide can only rely on the UV excitation to produce electron transition,and the electrons and electron holes recombine easily.Based on the above background,a nanometer anatase titania with high photocatalytic activity was fabricated by sol-gel method,using butyl titanate as precursor.In order to realize titanium dioxide responsing visible light,we succeed in doping modification of titanium with Fe,V,Cr,N,four elements through sol-modification,gel-modification,and atmosphere modification.The modified titanium dioxide were characterized by XRD,TEM,particle size analysis,UV vis absorption spectroscopy and XPS.We compare the degradation effect of modified titanium dioxide in saturated methyl orange under visible light,and results show that N-doped TiO₂?N-TiO₂-NH₃?calcined by ammonia atmosphere not only realizes the visible response,but also reduces the electron-electron hole recombination probability.With modified titanium dioxide catalyst?N-TiO₂-NH₃?,Triton X-100 as surfactant and alcohol soluble polyurethane as coating former,research and fabricate a kind of alcohol soluble coating liquid which can be cured on glass surface.Under visible light,formaldehyde degradation efficiency reached 83%in 6hours and toluene degradation efficiency reached 55%.The coating equals to?according to<indoor purification performance of coating material with air purification function>.At the same time,this paper also shows the formaldehyde concentration,amount of catalyst and light intensity on the influence of coating photocatalytic degradation efficiency of formaldehyde.Combined with the Langmuir-Hinshelwood model,calculate the coating adsorption equilibrium is 0.0031 L/?g,and the coating photocatalytic reaction rate is 1.01?g L^-1s^-1.