Study On Purifying Air By TiO₂ Nanotubes

Nowadays,indoor air pollution is increasingly serious.The concentration of pollution is exceeding the standard,most of all is formaldehyde.More attention is forced on the danger and the treatment of indoor formaldehyde pollution because it hurt human body badly.There are many air purifier sold in the market but lack of unify standard in this industry.This paper was mainly about design and making an purifier with TiO2 nanotubes as a catalyst and activated carbon sponge as adsorbed layer.The paper was studied on the degradation of formaldehyde which is the most representative indoor air pollutants.Firstly,in the study on enlarging the preparation of TiO2 nanotubues,it worked with the result of SEM,XRD and degradation of Acid Orange.Using a extra current on the board can improve the degradation efficiency and it was best result when the current was from 0.1A to 12.5A.Secondly,the internal material type,specification and internal structure of the air purifier were designed.In order to improve the efficiency,0.1 A current was chosen to put on the samples of TiO2 nanotubes.The method of acetylacetone colorimetric was used to measure the concentration of residual formaldehyde in the air.The results showed that the air purifier was able of continuous running for 24 hours safely,and the purified effect waswell.A new decorated room was marked as Place A whose space was 34.5 m3.The initial concentration of formaldehyde was 0.1225 mg/m3.After running 7 hours,the concentration of formaldehyde was reduced to 0.0169 mg/m3,and the degradation rate was 86.2%.For further test,this equipmenL's used in Place B,whose space was 87.9 m3 and the initial concentration of formaldehyde was 0.3337 mg/m3.Firstly,the comparative experiment between activated carbon adsorption layer and the part of photocatalysis technology was carried out.The result showed that the degradation was 81.7%and 70.3%respectively after working 8 hours and the whole machine was 90.92%.In the photoelectric effect catalytic and photocatalytic comparative experiments,the degradation rate was 78.9%and 53.6%respectively,after 10 hours purificating.Under the extra current is 1.47 times of that without current.When exploring different humidity conditions affecting air purifier's work,we found that when the relative humidity of 61%,the air purifier's purification effect is better and formaldehyde had been completely removed from the air in 8 hours.Lastly,in the text of service life,after using 480 hours the activated carbon adsorption layer lost its activity and the photocatalyst still worked the same result after using 960 hours and washing its surface.