Solvent-free preparation of superhydrophobic and photocatalytic monoliths for water treatment applications

Sustainable and practical preparation of nanostructured materials with superhydrophobicity and photocatalytic activity remains a persistent challenge for a diverse range of applications including water treatment and selfcleaning surfaces. This study reports solvent-free mechanochemical grafting of polydimethylsiloxane to photo-catalytic TiO2 nanoparticles with a diameter of 21 nm and generation of a monolithic material with demonstrated use in adsorption and degradation of organic pollutants. The monolith exhibited bulk superhydrophobicity with a water contact angle of 1720 and sliding angle of 10. At the same time, the monolith effectively degraded organic pollutants such as methylene blue, under UV light with 92 % efficiency in 7 h. Furthermore, the superhydrophobic monolith demonstrated effective sorption of hexane, toluene, sunflower oil and pump oil from water with efficiencies approaching 90 %. These findings demonstrate the promise of solvent-free mechanochemical processes in developing nanostructured materials for water treatment applications.