Catalytic processes for obtaining inorganic nanostructures by using soft metals

A process for preparing a metal-oxide elongated nanostructure of the formula A1-zMz-oxide, A being a metal and M being a soft-metal foreign atom within a lattice structure of A-oxide, M being different than A, wherein 0<z≦0.05, the process comprising:

• providing a source of A atoms and a source for M atoms, and
• treating the A atoms and the M atoms under conditions permitting the formation of elongated nanostructures of the formula A1-zMz-oxide, wherein said conditions are at least one of an oxidative environment, elevated temperature, and reduced pressure.

A process for preparing metal-chalcogenide nanostructures of the formula A1-x-yMxBy-chalcogenide, A being a metal and M being a soft-metal foreign atom within the lattice structure of A-chalcogenide, and B being a metal, the process comprising

• providing a vapor phase comprising A-oxide of the formula A1-zMz-oxide and B-oxide, provided that A≠B and B≠M;
• and
• permitting said vapor phase to counter-flow a gaseous composition comprising chalcogene-carrying reacting gas, under conditions permitting formation metal-chalcogenide nanostructures of the formula A1-x-yMxBy-chalcogenide, x being equal to or smaller than z, and wherein 0<z≦0.05, wherein y is at most 0.3

A process for preparing metal-chalcogenide nanotubes of the formula A1-xMx-chalcogenide, the process comprising exposing a composition that comprises a metal-chalcognide of the formula A-chalcogenide and a metal component M to a temperature of at least 1,600° C. for a predetermined period of time, to thereby obtain the metal-chalcogenide nanotubes.

An elongated nanostructure comprising at least one layer of a metal-chalcogenide the formula A1-xMx-chalcogenide, at least partially coating an inner core of the formula A1-zMz-oxide, x being equal to or smaller than z and wherein 0<z≦0.05.

An elongated nanostructure having a radial dimension and a longitudinal dimension, the nanostructure comprising:

• a first portion of said longitudinal dimension comprising a solid core of the formula A1-zMz-oxide at least partially coated by at least one layer of a metal-chalcogenide of the formula A1-xMx-chalcogenide, x being equal to or smaller than z, wherein 0<z≦0.1, and
• a second portion of said longitudinal dimension comprising a hollow nanotube of a metal-chalcogenide of the formula A1-xMx-chalcogenide.

The elongated nanostructure of claim 41, wherein A is a metal selected from W, Mo, Re, Ti, Zr, Hf, Nb, Ta, Pt, Ru, Rh, Sn, In, and Ga;

• M is a metal selected from Pb, Bi, Sn, Sb, V, Ga, In, Hg, Nb and mixtures thereof;
• and said chalcogenide is selected from S, Se and Te.