Metal-Free Ternary-Composite Aerogel Based on Graphitic Carbon Nitride, Graphene Oxide, and β-Cyclodextrin for...

The adsorption-coupled degradation of dyes offers an attractive strategy for the remediation of industrial dye wastewater. Herein, a metal-free, porous ternary-composite aerogel was rationally designed and constructed using graphitic carbon nitride (g-C₃N₄), graphene oxide (GO), and β-cyclodextrin (β-CD). The g-C₃N₄/GO/β-CD aerogel (denoted as CNGOCD) exhibited excellent cooperative adsorption enrichment and photo-driven degradation capabilities for several organic dyes, including rhodamine B, methylene blue, and neutral red, achieving an adsorption capacity of 653.2 mg/g and a removal rate of 97.1%. These results outperformed traditional reduced graphene oxide (rGO) and rGO/β-CD aerogels. After five cycles, the CNGOCD aerogel maintained stable performance without a significant decrease in either adsorption or photocatalytic activity. Spectral analysis, electrochemical measurements, and density functional theory (DFT) calculations were employed to elucidate the adsorption mechanisms and the enhanced photocatalytic performance of the aerogel. Our findings suggest that GO enhances charge separation in g-C₃N₄ to boost photocatalytic activity, while β-CD prevents GO stacking, creating a porous architecture rich in active sites for rapid adsorption. Furthermore, this metal-free aerogel is eco-friendly due to no risk of heavy metal leaching, causing secondary pollution. The insights gained from this work provide a solid foundation for designing advanced, multi-purpose materials aimed at effective pollutant decontamination.