The Preparation Of The TiO₂/ACF Composite Photocatalyst And Its Formaldehyde Degradation Performance Studies

The impact of indoor environment on health is one of the important research direction in the development of urban construction and environmental engineering.With the improvement of people's living comfort requirements,indoor decoration rate rising,brings great threat to the indoor environment,IAQ decline gradually,increased indoor VOCs pollution,particularly formaldehyde pollution.TiO₂ photocatalytic technology can effectively degrade the interior formaldehyde,and have the characteristics of safety,durability and thoroughness.But since TiO₂ is powder itself,it can only degrade the formaldehyde that exposed to it,the purification efficiency is low,and it is difficult to separation recovery after use.The study of how to overcome these problems,produce an effective load photocatalyst and air purification device has become a hot spot in photocatalytic field.In this paper,firstly,we combined the principle of adsorption with catalytic principle,used impregnated-pulling method,with ACF as the carrier,loaded nanoTiO₂ made a kind of composite photocatalyst.Secondly,constructed experiment platform,optimized the air purification device,designed the experiment scheme,carried out the formaldehyde degradation research with the composite photocatalyst,determined the best experimental catalytic materials.The effect of the TiO₂ structure on its catalytic properties was analyzed by X-ray diffraction?XRD?and scanning electron microscopy?SEM?.Then based on the study of the influencing factors,carried out the orthogonal experiment and determined the optimum catalytic conditions.Finally,under the optimum catalytic condition,conducted the formaldehyde degradation experiment,evaluated the performance of the purifier.The main findings are as follows:?1?Compared with single adsorption and photocatalytic,TiO₂/ACF composite photocatalyst using ACF adsorption properties gathered formaldehyde on TiO₂ surface,collaborative degradation,the effect is better.Combined ACF adsorption capacity and load TiO₂ usage consideration: the 3mm thickness ACF is the most suitable load material.?2?By comparing the experimental degradation performance of four groups of TiO₂ with the load rate of 23.29 %,45.88 %,65.87 %,86.34 %,it has been shown that it is most optimal choice to select the 45.88 % TiO₂ load composite purification,whose degradation efficiency can reach 90% after 120 min.?3?By doing XRD?SEM representation of the composite photocatalysts,analyze the effect of TiO₂ morphology structure on its catalytic properties.The result of performing is same as the experiment,the performance of composite photocatalyst is best when the TiO₂ load quality is 45.88%.?4?Then,indoor environmental factor orthogonal experiment was carried out to find the significant factors of influencing the purifier in purifying air quantity,sorting in the following way: initial concentration of formaldehyde > gas flow speed > uv light intensity.The best catalytic conditions are at temperature of 24?²6?,relative humidity of 50%⁷0%,1.71 m/s air velocity,210 lux light intensity and initial concentration of formaldehyde 1.0mg/m3.?5?Under the best catalytic condition,convert standard volume V=30m3 and purification efficiency?=1.425 m3/?w.h?are available,which is classified as high efficiency air purifier according to <<Air purifier >>.A composite photocatalyst was prepared by studying the theory of photocatalysis and combining adsorption purification method.Use the TiO₂/ACF composite photocatalyst to formaldehyde purification experiment,combined with XRD?SEM analysis,gave out the best catalytic materials.Based on this,analyze the influence of environmental factors to light catalysis,and obtained the best catalytic conditions.