Preparation And Photocatalytic Performance Of TiO₂-SiO₂Composite Aerogels In Ionic Liquids

TiO2-SiO2composite aerogels are mesoporous solid materials consisted of the TiO2and SiO2gel particles dispersed and reunited mutually. They are one of the good photocatalysts, which have broad application in in treating of in the waste water and gas with various pollutantsIonic liquids have many characteristics, such as strong solubility, very low vapour pressure and low surface tension, at present, some researchers had successfully prepared TiO2and SiO2aerogels by ambient pressure drying with ionic liquids, which offer a new method for aerogels and have huge advantage.Using tetraethyl orthosilicate and tetraethyl titanate as Si resource and Ti resource, block TiO2-SiO2composite aerofels were prepared with [HMIM]Br by Sol-Gel method. The microstructure of the composite aerogels were characterized by FT-IR, SEM, XRD, DRS, and N2adsorption-desorption measurement, and the photocatalytic properties were studied by utilizing rhodamine B as degradation agent under uviol lamp, the main consequence show that:1、Using absolute ethyl alcohol (EtOH) as aging liquid, TiO2-SiO2composite aerogels were prepared at40℃in different molar ratio n(Si)/n(Ti)/n[ILs(additive amount)]. The results indicate that:the obtained TiO2-SiO2composite aerogels at n(Si)/n(Ti)/n[ILs(additive amount)]=1:2:0.5which calcined for3h at600℃have average pore size(3.654nm), pore volume(0.284cm3·g-1) and surface area(311.3m2·g-1); the photocatalytic results show that: composite aerogels present a higher photocatalytic degradation ratio than P25, degradation rate has reached81.33%at10h.2、Using [HMIM]Br and EtOH as aging liquid, TiO2-SiO2composite aerogels were prepared at40℃with n(Si)/n(Ti)/n[ILs(additive amount)]=2:1:0.5. The results indicate that: the TiO2-SiO2composite aerogels at c(ILs)=0.0028mol·L-1which calcined for3h at600℃have average pore size(3.61nm), pore volume(0.294cm3·g-1) and surface area(325.6m2·g-1); the photocatalytic results show that:composite aerogels present a higher photocatalytic activity, degradation rate has reached91.33%at10h.