Sheng-Siang Huang, Yu-Hsiang Lin, Wesley Chuang
Jan 11, 2018
Citations
1
Influential Citations
27
Citations
Journal
ACS Sustainable Chemistry & Engineering
Abstract
A series of nanocrystalline titanium (Ti) sub-oxides, including TiO, Ti2O3, Ti3O5, and Ti4O7, with high surface area and activity are successively synthesized using a facile synthesis method that combines the sol–gel and the energy-efficient vacuum-carbothermic (SG-VC) processes. The combination results in synergy in producing nanomaterials with high surface area (>100 m2 g–1), good conductivity, and rich intra-grain defect features, giving the oxides unique surface activities suitable for particular electrochemical applications. The phase compositions of the resulting powders are primarily determined by two process parameters, including the carbothermic carbon (C) content, expressed as the C-to-Ti molar ratio of the reactant powder, and the cooling protocol. Carbothermic C contents exceeding a threshold of C/Ti ∼ 3.7 exclusively produced non-Magneli phase (MP) oxides including TiO and Ti2O3, while the MP oxides, Ti3O5 and Ti4O7, can be formed only with lower C contents combined with selected quenching pr...