Superhydrophobic TiN-Coated Cotton Fabrics with Nanoscale Roughness and Photothermal Self-Healing Properties for Effective Oil–Water Separation

A sustainable and strong superhydrophobic photothermal self-healing cotton fabric (SPS cotton fabric) was prepared by the simple one-pot method using nano-titanium nitride (TiN), hydroxyl-terminated polydimethylsiloxane (HPDMS), and tetraethyl orthosilicate (TEOS). After nano-TiN is adsorbed to the cotton fabric by hydrogen bonding, HPDMS and TEOS are catalyzed by ammonia to form a PDMS-SiO2 hybrid on the cotton fabric, and finally the SPS cotton fabric is obtained. After plasma etching, cotton fabric can quickly restore superhydrophobicity by light irradiation. The micro–nanocoating on the SPS cotton fabric can resist at least 10 sandpaper abrasion cycles and etching of acid and alkali solutions without losing its superhydrophobicity. Owing to the good water repellency, the separation efficiency of the SPS cotton fabric can reach more than 98.00% for various oil–water mixtures. Even after 10 separation cycles, the separation efficiency only decreased by 0.20%, showing potential applications for waste oil treatment.