Surface chemistry regulation of nanoparticle coatings on activated carbons for rapid and long-lasting adsorption of organic pollutants

Abstract

The nature of activated carbons (AC) to possess large specific surface areas and highly developed internal channels, is beneficial to absorb a variety of organic pollutants for practical applications in widespread areas, such as odor removal, flue gas cleaning and water purification. However, the domination of water affinity on AC could promote the adsorption to saturation in a short period, hindering the adsorptive performance on organics and reducing the service life severely. Thus, a simultaneous demonstration of the remarkable adsorptive property along with moisture resistance is of great significance. In this work, the superhydrophobic ACs with selective adsorptive property were fabricated via the combination of pretreatment to roughen the surface and grafting of propyl trimethoxysilane on superhydrophobic nanoparticles. The design was verified by the theoretical calculation of density functional theory accompanied with surface grafting ratio, and the as-prepared ACs presented favorable damp- and water-proof ability in the long term, showing only 11.8% weight increment for up to 180 days in high humidity. More importantly, superhydrophobic ACs exhibited effective capture of organics for continuous adsorption under aqueous phase and humid conditions, with removal efficiency over 90%.