Adsorption driven preferential degradation of alkyl phenols on hydrophobic perfluoroalkyl modified {0 0 1}-TiO2

Abstract

Abstract Preferential degradation of low concentrated contaminants with high toxicity is of great environmental significant. Perfluoroalkyl group was adopted as functional group to construct hydrophobic surface on highly exposed {0\u202f0\u202f1}-TiO2 for preferential degradation of nonyl phenol. The modified electrode showed superior hydrophobicity with contact angle of more than 160° after optimization of preparation condition. Besides, the modified electrode improved light absorbance ability of visible light, leading to better photocatalytic property. The degradation of NP, OP and HP on the modified {0\u202f0\u202f1}-TiO2 was obviously more efficient over that unmodified, which was about 1.5 times in the kinetic constant, showing preferential degradation of alkyl phenols on perfluoroalkyl decorated {0\u202f0\u202f1}-TiO2. Preferential degradation on the modified {0\u202f0\u202f1}-TiO2 was due to the superior adsorption ability to alkyl phenols. The adsorption capacity to alkyl phenols on the modified electrode was more than 2 times over the that unmodified. The adsorption of alkyl phenols on the hydrophobic electrode was further studied by in-situ infrared. It was found that there was specific hydrophobic interaction between the alkyl group of alkyl phenols and the perfluoroalkyl group modified on photocatalyst surface, which was the reason of alkyl phenols preferential degradation on the hydrophobic photocatalytic interface. The results showed great potential applications in selective wastewater treatment.