Preparation and characterization of λ-Ti3O5 by carbothermal reduction of TiO2

λ-Ti3O5 powders were prepared by carbothermal reduction of nano-TiO2 (coated by inorganic) in argon atmosphere. The compound formation mechanism was described as well in this rote. The products synthesized under different heating temperatures, nano-carbon black contents and argon flow rate were investigated by X-ray diffraction (XRD). It indicated that high purity λ-Ti3O5 powders have been obtained by carbon black content of 4.5 wt% at 1050 °C for 3 h in argon flow rate 0.5 L min−1. The morphology of λ-Ti3O5 powders was characterized by scanning electron microscope (SEM). Meanwhile, the optical property of obtained λ-Ti3O5 powders was analyzed by ultraviolet–visible (UV–Vis). The results showed that the average size was about 3.0 ± 1.0 μm and the specific surface area (BET) was 12.82 m2 g−1. λ-Ti3O5 powders exhibited high absorption in the optical absorption bands ranging from 200 to 1400 nm. The isolation of λ-Ti3O5 can be obtained from as-prepared samples by NaOH etching, as demonstrated by Raman spectra. The conductivity of samples was 0.68 Ω cm−1 while it was 3.14 × 10−2 Ω cm−1 after etching.