Fabrication of graphene oxide vortex ring particle for efficient adsorptive removal of organic dyes from water

Graphene-based vortex ring aerogels, characterised by high surface area and controllable structures, represent optimistic candidates for the adsorptive removal of pollutants. In this study, graphene oxide-vortex ring (GO-VR) aerogel particles were synthesised by impacting GO droplets onto cetyltrimethylammonium bromide (CTAB) solutions, which drives the formation of a stable VR hydrogel. The hydrogel was then produced into an aerogel after a freeze-drying process. GO concentration and impact height were key parameters in influencing the VR shape formation, while shape evolution was independent of GO droplet volume. Moreover, CTAB concentration did not affect the particle shape but improved the hydrogel stability. Optical microscopy and SEM imaging characterisation techniques confirmed the formation of the core-shell structure and revealed that the donut-shaped GO-VR aerogel particles showed the highest porosity, while ball-shaped exhibited the least. Adsorption experiments with model dyes showed the highest adsorption capacity, particularly the smallest size of 10 μl and the donut shape displayed superior adsorption efficiency equal to its own weight (1 g/g) significantly surpassing reported GO-based materials values. Adsorption Kinetics were studied using Pseudo-second-order (PSO) and intraparticle diffusion (IP) models; donut-shaped GO-VR particles showed the rapid adsorption rate and highest diffusion efficiency. Therefore, promising GO-VR particles offer a novel approach to growing superior adsorbents, which will consequently enhance water purification technologies.