Nanostructured titanium oxide material and its synthesis procedure

Abstract

Nanomaterials of the JT phase of the titanium oxide TiO 2-x , where 0≦x≦1 having as a building block a crystalline structure with an orthorhombic symmetry and described by at least one of the space groups 59 Pmmn, 63 Amma, 71 Immm or 63 Bmmb. These nanomaterials are in the form of nanofibers, nanowires, nanorods, nanoscrolls and/or nanotubes. The nanomaterials are obtained from a hydrogen titanate and/or a mixed sodium and hydrogen titanate precursor compound that is isostructural to the JT crystalline structure. The titanates are the hydrogenated, the protonated, the hydrated and/or the alkalinized phases of the JT crystalline phase that are obtained from titanium compounds such as titanium oxide with an anatase crystalline structure, amorphous titanium oxide, and titanium oxide with a rutile crystalline structure, and/or directly from the rutile mineral and/or from ilmenite. The titanates are submitted to dynamic thermal treatment in an inert, oxidizing or reducing atmosphere to produce the JT phase of the TiO 2-x , where 0≦x≦1 with an orthorhombic structure.

1 . Nanomaterial of hydrogen titanate and/or mixed sodium and hydrogen titanate, having the formula HTiO 2  and/or Na x H 1-x TiO 2 , wherein x is from 0 to less than 1, the hydrogen and sodium atoms are in the interlayer regions of the orthorhombic structure and said nanomaterial has nanofibrilar and/or nanotubular morphology constituted of piled structural layers that are folded or rolled inwards into themselves, or formed by overlapped semitubes. 
     
     
         2 . The nanomaterial of  claim 1 , wherein said nanomaterial has an orthorhombic structure, which is isostructural with TiO 2-x , where 0≦x≦1, and whose unit cell is described by at least one of the space groups 59 Pmmn, 63 Amma, 71 Immm or 63 Bmmb. 
     
     
         3 . The nanomaterial of  claim 1 , wherein the cell parameters of the crystalline lattice which is orthorhombic are: a from 0.263 nm to 0.331 nm; b from 0.332 nm to 0.448 nm, and c from 0.635 nm to 0.902 nm, for the case of the 59 Pmmn space group, and from 1.368 nm to 1.905, for the case of the 63 Amma, 71 Immm, and 63 Bmmb space groups; with α=β=γ=90° 
     
     
         4 . The nanomaterial of  claim 1 , wherein said nanomaterial has a disordered mesoporosity with an average pore diameter between 3 and 25 nm and a specific area between 100 and 600 m 2 /g. 
     
     
         5 . The nanomaterial of  claim 1 , wherein said nanomaterial has a nanofibrilar and/or a nanotubular morphology with dimensions of 3 to 50 nm in diameter and lengths from 0.1 to 100 μm. 
     
     
         6 . The nanomaterial of  claim 1 , wherein said nanomaterial has a nanotubular morphology constituted by 1 to 50 structural layers with an inter-layer spacing in the range of 0.635 nm to 0.902 nm for the 59 Pmmn space group, and from 0.684 nm to 0.953 for the 63 Amma, 71 Immm, and 63 Bmmb space groups.