Facile synthesis of SiO2–TiO2 photocatalyst nanoparticles for degradation of phenolic water pollutants

Abstract

A facile synthesis of polyethylene glycol-templated silica–titania (PEG-templated SiO2–TiO2) nanoparticles has been carried out using sol–gel reactions by partial-prehydrolysis of tetraethoxysilane and titanium isopropoxide. The prepared nanomaterials have been investigated by N2 adsorption, FTIR, FT-Raman, TG-DSC, XRD, TEM, DLS, 13C and 29Si MAS NMR and XPS analysis to characterize the phase composition and microstructure of the samples. The photocatalytic performance of the SiO2–TiO2 nanoparticles was evaluated by photooxidative degradation of the alkylphenol derivatives aqueous solution. It was shown that their photoactivity in the removal of alkylphenol ethoxylates from aqueous solution was higher than for porous titania nanoparticles. The incorporation of PEG template into the inorganic network with subsequent formation of nanoporous structure will increases the efficiency of the SiO2–TiO2 nanoparticles. It was shown that the polymeric species played a significant role in the generation of pores by the hybridization with inorganic oxides on the molecular scale due to hydrogen bonds taking place at the ether moieties. The advantages of including thermally removable PEG template in terms of increasing surface, mesoporosity and photon absorbance at UV–visible wavelengths to give nanoengineered photocatalytic materials is described.