Photocatalytic Performance Of Titanium Dioxide Complex Material Supported By Rice Husk

The TiO2complex samples were produced through sol-gel method in the particular calcination temperature and keeping time, using Ti(OC49)4rice husk (RH) and methenamine as the reactants. The Differential scanning calorimetry (TG/DSC) was employed to characterize the thermo performance of precursor. Some property analyses were conducted, including X-ray diffraction (XRD), Brunauer-Emmet-Teller (BET), Scanning electron microscope (SEM), Fourier transform infrared (FT-IR), UV visible diffuse reflectance (UV-Vis) and photocatalytic experiments, using methyl orange as the degradation solution. The effects of calcination temperature, keeping time, apparent acidity, cycle photodegradation process, pH and concentration of initial methyl orange solution were discussed. The main conclusions are as follow.(1) The samples of RH/TiO2and N/RH/TiO2have the better ultraviolet and visible light photocatalytic activity separately, as a type of catalyst, possessing a large produce and use value.(2) In the result of adding RH in the complex of RH/TiO2samples and N/RH/TiO2samples, the sizes of crystal could be limited in a small range of10 nm-25nm. The particles of TiO2could be dispersed on the surface of rice husk ash, the skeleton of RH after burning. It could inhibit the phenomenon of agglomerate. And the surface area become larger, which can improve the adsorption of complex samples and the photocatalytic activity. It also could increase the absorption of UV-light.(3) The calcination temperature, keeping time, the apparent acidity, cycle photodegradation process, pH and concentration of initial methyl orange solution all have a cent of significant impact on photocatalytic activity in the photodegradation process.(4) When the calcination temperature is around500℃, keeping time is3h-4h, apparent acidity is6.20, pH=5.0, concentration is15mg/L, the samples have a better performance in photodegradation of methyl orange. After5times, the RH/TiO2still has a better photocatalytic activity.(5) The complex samples, prepared at600℃1h, have a larger surface area and average pore size, and a better adsorption of methyl orange solution. The adsorption process meets the Freundlich adsorption model. The adsorbents of RH/TiO2and N/RH/TiO2are6.45m/g and8.87mg/g separately.(6) Doping N into RH/TiO2samples could decrease the forming time. It could inhibit the transformation of crystal from anatase to rutile to some extent. It could improve the bond of Ti-O-Si to form and let the absorption spectrum move to the red light part. It also could make the complex samples having a degree of photocatalytic performance in visible light. The reaction rate of visible light photodegradation process arrives0.0143min-1, meeting with the first-order reaction kinetics.