Sol-gels 95 Sol-gel process 48 Silica 45 Sol-gel 41 Sols 28 article 23 Titanium dioxide 22 Gelation 20 Gels 20 Thin films 20 Mesoporous materials 18 Nanoparticles 16 Hydrolysis 14 X ray diffraction 14 priority journal 14 Hydrogels 13 SOL-GEL 12 Synthesis (chemical) 12 silicon dioxide 12 Microorganisms 11 chemistry 11 Film preparation 10 Hybrid materials 10 Nanostructured materials 10 Photocatalysis 10 Silica matrix 10 adsorption 10 nonhuman 10 Algae 9 Chlorella vulgaris 9