Study On The Preparation, Adsorption And Photocatalytic Degradation Of Bamboo Charcoal-TiO₂ Composites For Formaldehyde

In this thesis,according to specific porosity of bamboo charcoal(BC)and photocatalytic oxidation of TiO₂ to formaldehyde,TiO₂ sol was prepared by a sol-gel method using butyl titanate as raw material,and TiO₂ photocatalyst loaded on granular bamboo charcoal(TiO₂/BC)was prepared by a molecular soakage-filtration method using granular bamboo charcoal as supporter.The microstructure of TiO₂/BC was characterized by SEM,XRD,and so on.The adsorption performance of TiO₂/BC and BC composites for formaldehyde as well as the adsorption speed were investigated.In addition,the optimum conditions of photocatalytic oxidation of TiO₂/BC to formaldehyde were studied. The results show that:The BC particles are homogeneously covered by anatase TiO₂ photocatalyst through a sol-gel method,which didn't block the pore space but mainly dispersed in big pore and surface hollows of BC.Both BC and TiO₂/BC possess favorable adsorption ability to formaldehyde,but the capacity of TiO₂/BC was better than that of BC when the capacities were saturated.The adsorption mass of TiO₂/BC to formaldehyde was more than that of BC in per unit time.Within the loading range,the adsorption capacity of TiO₂/BC to formaldehyde increases with the loading times,but the optimal time is three.It is clear that the use of TiO₂/BC photocatalysts under UV significantly enhanced the photodegration of formaldehyde relative to BC alone,although the single bamboo charcoal also has a little performence for the degradation of formaldehyde.Under the condition of degradation experiment,the degradation rate of formaldehyde could attain 45.6%in 3 hours using three-time loading TiO₂/BC photocatalysts under UV.To the degradation rate of formaldehyde,TiO₂/BC photocatalysts had a higher photocatalytic activity under UV irradiation,than under sunlight or fluorescent light,and the rate can be improved under sunlight comparing with fluorescent light.However,when intensity of UV is up to constant,the degradation rate can not be effectively enhancd by increasing the intensity of UV.