Bending vibrations Absorption peaks 1 Adsorption peaks 1 Alkanolamines 1 Alumina 1 Aluminum 1 Aluminum oxide 1 Amorphous silicon 1 Condition 1 Crystallinity 1 Diethanolamine 1 Different Si/Al ratio 1 Ethanol 1 Ethanolamines 1 Flower structures 1 Fly ash 1 Microstructure 1 Mineral polymer precursor 1 Minerals 1 Nanoscale size 1 Performance 1 Platinum compounds 1 Polymer precursors 1 Reaction mechanism 1 Semiconductor materials 1 Silica 1 Sol- gel methods 1 Sol-gel process 1 Sol-gels 1 Solvothermal techniques 1