Sol–Gel Synthesis of Nanostructured Mesoporous Silica Powder and Thin Films

Figure 12

Schematic diagram of silica film growth via electro-assisted mechanism [51]. The conventional sol–gel coating process has limitations on the preparation of crack-free thicker (>1 μm) silica thin films. But electrochemically assisted technique offers to prepare thicker and uniform films due to the generation of hydroxide ions which creates an additional driving force for catalytic condensation reaction leading to the concomitant formation of ticker (ca.10 μm) silica thin film over the substrate surface [48, 53].