Bio-templated 3D porous graphitic carbon nitride hybrid aerogel with enhanced charge carrier separation for efficient removal of hazardous organic pollutants

Abstract

Graphitic carbon nitride (g-C3N4) hybrid aerogels (GHAs) with different proportions of g-C3N4 were prepared using g-C3N4, carboxymethyl cellulose, and β-cyclodextrin. GHAs have demonstrated high porosity, large specific surface area, rich three-dimensional network structure. GHAs demonstrated an excellent synergistic effect on the photocatalytic and adsorptive properties. Especially, GHA1 (the ratio of g-C3N4 and aerogel component was 1:1) exhibited a good synergy in photodegradation and adsorption, with a Rhodamine B (Rh B) removal up to 97.99% in 90 min. In five cycling experiments, the GHA1 showed a good long-term stability. The aerogels can be easily isolated and maintains its excellent photocatalytic properties. Compared to pure g-C3N4, GHA1 has a stronger photocurrent, which is due to the transmission of light to the surface of the catalyst, promoted photo-generated electron-hole pairs, and inhibited recombination of electros and holes. Finally, mechanistic studies reveal that the superoxide radicals (O2−) are the main active groups in the photocatalytic degradation process. This work provides a useful perspective in design and fabrication of hybrid aerogel composites with an enhanced photocatalytic activity.