A multifunctional gelatin-based aerogel with superior pollutants adsorption, oil/water separation and photocatalytic properties

Designing multifunctional adsorbents that can satisfy sophisticated requirements in complex water treatment fields remains challenging these days. In this work, an original and environment-friendly gelatin-based organic-inorganic composite aerogel equipped with integrative functions was fabricated through facile methods. The uniform dispersion of TiO2 nanoparticles was successfully achieved in the three-dimensional structure of the composite aerogel, and the branched polyethyleneimine (PEI) was cross-linked onto it through the effect of glutaraldehyde. The gelatin/TiO2/PEI (GTP) aerogel had a hierarchical porous structure and a superamphiphilic surface, which endowed it with excellent oil/water separation properties, for both oil/water free mixtures and oil-water emulsions. Both cationic (methylene blue and crystal violet) and anionic (congo red and methyl orange) organic dyes could be adsorbed by the GTP aerogel with good adsorption capacity. It was noteworthy that the GTP aerogel was capable of realizing dye degradation because of its photocatalytic performance. Furthermore, this composite aerogel was able to remove copper ions from aqueous solutions with high capacity and good reusability. The regeneration of the GTP aerogel was realized by methanol and EDTA for dyes and copper ions respectively. Combined with comprehensive functions including oil/water separation, organic dyes adsorption, copper ions removal and photocatalytic property, the bio-based organic-inorganic composite GTP aerogel holds great promise for practical usage in water remediation, especially in the treatment of polluted water with complex components.