Fiber engineering of silica-based aerogels with surface specificity and regenerability for continuous removal of dye pollutants from wastewaters

Abstract

Aerogels are attractive candidates as advanced adsorbents in water-treatment given their high specific surface area and reticulated porous structure. We present here hollow silica aerogel fibers (SAFs) engineered based on a wet spinning approach for dye removal from wastewaters. The surface characteristics of SAFs can be flexibly adjusted via a simple post-modification by silane coupling agents, delivering not only high dye removal efficiency but also great feasibility for various dyes. By the means of incorporating commercially used photocatalysis active nanoparticles (P25) into SAFs (denoted as SAF-P25), a photo-regenerable SAF-P25 adsorbent can be successfully prepared. SAF-P25 can recover its initial adsorption properties via a simple UV or natural light irradiation treatment. Consequently, the novel SAF-P25 is able to continuously adsorb and degrade dyes in wastewaters with a long-term dye removal performance. In addition to high adsorption efficiency and photo-renewability, the SAF-based adsorbent also preserves the merits of low cost, good scalability, wide applicability, and operation simplicity; all these make it become a promising dye removal system for future wide usage in various wastewater purifications. • Silica aerogel fibers (SAFs) were manufactured by wet spinning. • Specific surface modification endowed SAFs with adsorption selectivity. • After the introduction of photocatalyst, SAFs showed renewability and maintained excellent adsorption performance. • SAF-P25 can continuously and efficiently remove dyes under UV or natural light.