earticle

영어

Grafting titanium alkoxide showed the enrichment of surface OH groups on TiO2 through the test reactions in oleic acid, olive oil, and microalgal lipids. OH groups enrichment occurred only on the surface. The absorption reduction predicted the release of active sites by the removal of water molecules as moisture. The XRD profiles, before and after heat treatment, indicated that hydroxyl-rich surfaces retain the original structural properties with strengthened surface acidity. The catalyst had a protonating ability towards the solvent even at pH 5, where TiO2 support were positively charged. The increased acidity was demonstrated by the accelerated reaction rate. After silica solid phase extraction of crude algal lipids, neutral lipids, glycolipid, and phospholipids yielded, after elution with chloroform, acetone, and methanol, respectively. Degradation curves showed changing rate constant in the descending order, TiO2 grafted, TiO2 double dosage, and TiO2 equal dosage. The photo-catalysis suggested that enrichment of surface OH groups strengthened the catalysis due to the activation of Lewis and Bronsted sites.