Photocatalytic superhydrophobic SH-ZnO-PDMS-coated fabric for efficiency self-cleaning and oily water separation

Abstract

The frequent occurrence of oil spills in recent years has led to serious contamination of water resources, and materials with superhydrophobic surface properties have attracted much attention for crude oil recovery and water contamination remediation. However, the fragile robustness of superhydrophobic materials greatly hinders their practical applications. Herein, we prepared the robust, photocatalytic superhydrophobic material of SH-ZnO-PDMS@fabric by a simple two-step immersion method. Zinc oxide nanoparticles (ZnO NPs) provided the rough surface structure, and fluorine-free dodecyltrimethoxysilane (DTMS) provided the low surface energy. Polydimethylsiloxane (PDMS) was introduced as a binder to strengthen the force between the nanoparticles and the fabric. The cotton fabric showed excellent superhydrophobicity with a water contact angle (WCA) range of 146.9–156.6°. The methylene blue (MB) in water was basically degraded after 12 h of exposure to UV lamp, manifesting that the cotton fabric had excellent photocatalytic property. The cotton fabric also showed excellent self-cleaning and antifouling properties. Importantly, SH-ZnO-PDMS@fabric maintained superhydrophobic properties after mechanical abrasion, ultrasonic washing, UV irradiation, and acid/alkali immersion. The prepared superhydrophobic materials can be repeatedly used to separate various oil–water mixtures due to their superhydrophobic and recyclable properties. This versatile, efficient, and simple strategy has good application prospects in water pollution remediation and oily wastewater treatment.