Process for the formation of metal oxide nanoparticles coating of a solid substrate

A process for forming a coating comprising metal oxide or mixed metal oxide nanoparticles of one or more metals selected from the group consisting of tin, antimony, germanium and tellurium on a solid substrate, comprising:

• providing a basic metal-containing solution containing at least one metal selected from said group and hydrogen peroxide, and contacting said basic metal-containing solution with a solid substrate having oxygen-containing chemically reactive groups on its surface, wherein said solid substrate having oxygen-containing chemically reactive groups on its surface is contacted with said basic metal-containing solution and hydrogen peroxide solution under conditions allowing formation of peroxynanoparticle coating on the solid substrate upon addition of an antisolvent capable of inducing a precipitation of the peroxynanoparticle coating, wherein peroxynanoparticles present in the peroxynanoparticle coating have a diameter of less than 10 nm, with no agglomeration occurring in the basic metal-containing solution, as is evident by scanning electron microscopy or transmission electron microscopy;
• and
• heat treating the peroxynanoparticle coating to obtain a metal oxide or mixed metal oxide nanoparticle coating layer of less than 20 nm;
• wherein the heat treating comprises calcining the peroxynanoparticle coating on the solid substrate at a temperature of 300-1000° C.