Dawson Margaret, Soares Gabriela Byzynski, Ribeiro Caue
Department of Materials Engineering, Universidade Federal de São Carlos, Rodovia Washington Luis KM 235 SP-310, São Carlos, São Paulo, CEP 13565-905, Brazil.
J Nanosci Nanotechnol. 2013 Jul;13(7):5126-33. doi: 10.1166/jnn.2013.7603.
Anatase TiO2 is a promising photocatalyst due to its chemical stability, non-toxic characteristics, notable UV light absorption as well as photo-corrosion resistance and oxidative properties. Surface area and TiO2 dispersion quality are important factors that affect photoactivity of TiO2:SiO2 nanocomposites. In order to improve these factors, TiO2 nanoparticles were immobilized on mesoporous silica substrate through the polymeric precursors method, obtaining the nanocomposites in a simple routine. The TiO2 resin was synthesized by the polymeric precursors method and different resin thickness (0.5; 1.0; 2.0; 3.5; 5.0 nm) on silica were synthesized by calcination during 4 hours at 450 degrees C in pH 1.5. The selected pH for immobilization ensured adhesion of TiO2 nanoparticles onto the silica substrate surface. X-Ray Diffraction patterns indicate that all samples were predominantly anatase phase and immobilization improved surface area. Ametryn kinetic evaluation presents better results for SAM 3.5 and SAM 0.5. The results show that difference in TiO2 loading, surface area and crystallinity of samples are factors that influence photocatalytic efficiency.
锐钛矿型二氧化钛是一种很有前景的光催化剂，因其具有化学稳定性、无毒特性、显著的紫外光吸收能力以及抗光腐蚀和氧化性能。表面积和二氧化钛的分散质量是影响TiO₂:SiO₂纳米复合材料光活性的重要因素。为了改善这些因素，通过聚合物前驱体法将二氧化钛纳米颗粒固定在介孔二氧化硅载体上，以简单的流程获得纳米复合材料。通过聚合物前驱体法合成了二氧化钛树脂，并在pH值为1.5的条件下于450℃煅烧4小时，在二氧化硅上合成了不同树脂厚度（0.5、1.0、2.0、3.5、5.0纳米）的样品。选定的固定pH值确保了二氧化钛纳米颗粒附着在二氧化硅载体表面。X射线衍射图谱表明，所有样品主要为锐钛矿相，且固定过程提高了表面积。莠灭净动力学评估显示，SAM 3.5和SAM 0.5的结果更好。结果表明，样品中二氧化钛负载量、表面积和结晶度的差异是影响光催化效率的因素。
