Study On The Purification Of Indoor Formaldehyde By New Photocatalytic Coating Additives

In recent years,the use of these materials has produced a large amount of formaldehyde due to the large amount of decoration materials such as artificial boards and latex paints used in interior decoration.Formaldehyde is the most important pollutant in the indoor environment,so the purification of indoor formaldehyde has attracted widespread attention.TiO₂ photocatalytic technology is widely used to purify indoor formaldehyde because of its reusability and strong stability.However,there is a serious deficiency in nano-TiO₂,the band gap of TiO₂ is wide,which causes it to be excited only by ultraviolet light.In view of this situation,plant pigments and commercial titanium dioxide（P25）were compounded to prepare paint additives,and the light absorption range of titanium dioxide was improved by the principle of dye sensitization.In order to explore the purification effect of this coating additive and its influencing factors,this experiment is carried out from the following aspects:（1）A laboratory-scale reactor for photocatalytic degradation of formaldehyde was designed to investigate the factors affecting the degradation of formaldehyde and the effect of photocatalytic coating additives on the degradation of formaldehyde.In this experiment,the influencing factors of formaldehyde degradation by P25photocatalyst and the effect of formaldehyde degradation were investigated.The main factors were the initial concentration of formaldehyde,light,humidity,temperature and the amount of P25 catalyst.（2）Three new photocatalytic coating additives with different colors were compounded.The prepared coating additives were characterized by SEM,UV-Vis DRS,and the effect of the coating additives and the response to visible light were observed.The effects of initial concentration of formaldehyde,illumination,humidity,temperature and the amount of additives on the degradation of formaldehyde by coating additives were investigated.The photocatalytic degradation of formaldehyde by coating additives and the optimum purification conditions of formaldehyde were proved by comparing with the single P25 photocatalyst.