TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The dispersion of metal oxide nanoparticles (A) comprise at least one crystalline metal oxide. The block copolymer (B) comprises at least one alkylene oxide block (AO) and at least one isobutylene block (IB), where the number-weighted average block length of the alkylene oxide block (AO) is from 4 to 300 monomer units and the number-weighted average block length of the isobutylene block (IB) is from 5 to 300 monomer units. The metal oxide nanoparticles (A) comprise oxides of at least one metal or semimetal M selected from titanium (Ti), niobium (Nb), tantalum (Ta), zirconium (Zr), manganese (Mn), aluminum (Al), iron (Fe), chromium (Cr), tin (Sn), antimony (Sb), lead (Pb), cesium (Ce), indium (In), barium (Ba) and vanadium (V). Metal oxide nanoparticles (A) comprises tin as the metal or semimetal M, and antimony as the doping element M'. The solvent (C) used is at least one compound selected from aliphatic alcohols and aliphatic ethers. Preferred Process: Reaction in step (a) is performed in the presence of at least one diblock copolymer (B) consisting of an alkylene oxide block (AO) and an isobutylene block (IB). Step (c) is preceded by step (c-pre) comprising applying the mixture obtained in step (b) on the solid substrate (S). Step (d) comprises applying a temperature of from 100 to 600 degrees C to the composite material (K), preferably 200 to 550X. Step (d) comprises heat treatment in at least two stages, a first stage (d1) involving exposure to a temperature of from 80 to 200 degrees C for from 1 to 24 hours, and a further stage (d2) involving exposure to a temperature of from 200 to 600 degrees C for from 1 to 5 hours. After step (d), the mesoporous material in step (e) is aged under the exclusion of oxygen, preferably at a temperature of from 200 to 600 degrees C. Preferred Parameters: The number average particle diameter of the nanoparticles according to step (a) is from 0.5 to 10 nm. The block copolymer (B) has a polydispersity index of from 2 to 20. EXAMPLE - No suitable example given.