Fabrication and characterisation of Magneli phase Ti4O7 nanoparticles

Pure Magneli phase Ti₄O₇ nanoparticles with diameters of 200-500 nm were successfully synthesised under hydrogen atmospheres. In this reported work, the influences of reduction of temperature and time on the reduced phases were investigated, and it is shown that pure Ti₄O₇ can be obtained by heating at 850°C for 5 h. The as-prepared materials are characterised by X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy, and the corresponding selected area electron diffraction indicates the single-crystal structure, which is also consistent with the XRD results. N₂ absorption (Brunauer-Emmett-Teller surface area) was also conducted on this material, the surface area being 8.351 m²/g. UV-vis diffuse reflectance spectra of the nanoparticles exhibited absorption beyond 325 nm, meanwhile, there is an absorption band that covers the visible-light wavelengths and extends into the near-infrared region.