Villa Silvia, Caratto Valentina, Locardi Federico, Alberti Stefano, Sturini Michela, Speltini Andrea, Maraschi Federica, Canepa Fabio, Ferretti Maurizio
Department of Chemistry and Industrial Chemistry, University of Genoa, Genoa 16146, Italy.
Department of Chemistry, University of Pavia, Pavia 27100, Italy.
Materials (Basel). 2016 Sep 10;9(9):771. doi: 10.3390/ma9090771.
The enhancement of the photocatalytic activity of TiO₂ nanoparticles (NPs), synthesized in the presence of a very small amount of magnetite (Fe₃O₄) nanoparticles, is here presented and discussed. From X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analyses, the crystallinity of TiO₂ nanoparticles (NPs) seems to be affected by Fe₃O₄, acting as nano-seeds to improve the tetragonal TiO₂ anatase structure with respect to the amorphous one. Photocatalytic activity data, i.e., the degradation of methylene blue and the Ofloxacin fluoroquinolone emerging pollutant, give evidence that the increased crystalline structure of the NPs, even if correlated to a reduced surface to mass ratio (with respect to commercial TiO₂ NPs), enhances the performance of this type of catalyst. The achievement of a relatively well-defined crystal structure at low temperatures ( = 150 °C), preventing the sintering of the TiO₂ NPs and, thus, preserving the high density of active sites, seems to be the keystone to understand the obtained results.
本文介绍并讨论了在极少量磁铁矿（Fe₃O₄）纳米颗粒存在下合成的二氧化钛纳米颗粒（TiO₂ NPs）光催化活性的增强情况。通过X射线衍射（XRD）和差示扫描量热法（DSC）分析，TiO₂纳米颗粒（NPs）的结晶度似乎受到Fe₃O₄的影响，Fe₃O₄作为纳米晶种，相对于无定形结构而言，有助于改善四方晶系TiO₂锐钛矿结构。光催化活性数据，即亚甲基蓝的降解和新兴污染物氧氟沙星的降解，表明NP的晶体结构增加，即使与降低的表面质量比（相对于商业TiO₂ NPs）相关，也能提高这类催化剂的性能。在低温（= 150°C）下实现相对明确的晶体结构，防止TiO₂ NPs烧结，从而保持高密度的活性位点，似乎是理解所得结果的关键。
