Candle soot as a template for fabricating superhydrophobic titanium dioxide film by magnetron sputtering

A superhydrophobic titanium dioxide (TiO₂) film with the template of a candle smoked Si wafer was successfully fabricated by magnetron sputtering. The film specimens were examined by X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, contact angle meter, scanning electron microscope (SEM), transmission electron microscope (TEM) and gas-sensitivity tests. The results showed that the TiO₂ solely deposited on the silicon wafer was hydrophilic, with its contact angel only 61°, while it became superhydrophobic with water contact angle up to 155° after depositing on candle smoked substrate. The SEM and TEM results showed that the TiO₂ morphology kept the spongy-like framework covering on the carbon clusters formed template. In this paper, the superhydrophobic TiO₂ was achieved on the candle soot without modification by low surface energy materials, which shows the dominance of the structure for preparing hydrophobic TiO₂ films. The TiO₂ films deposited on the candle soot more excellent gas sensitivity than pure TiO₂ films.