Peptide-Guided TiO2/Graphene Oxide–Cellulose Hybrid Aerogels for Visible-Light Photocatalytic Degradation of Organic Pollutants

Titanium dioxide (TiO₂), owing to its excellent photocatalytic performance and environmental friendliness, holds great potential in the remediation of water pollution. In this study, we introduce a green and facile strategy to fabricate TiO₂-based hybrid aerogels, in which the peptide FQFQFIFK first self-assembles into peptide nanofibers (PNFs), followed by in situ biomineralization of TiO₂ on the PNFs. The TiO₂-loaded PNFs are then combined with graphene oxide (GO) via π-π interactions and integrated with microcrystalline cellulose (MCC) to construct a stable three-dimensional (3D) porous framework. The resulting GO/MCC/PNFs-TiO₂ aerogels exhibit high porosity, low density, and good mechanical stability. Photocatalytic experiments show that the aerogels efficiently degrade various organic dyes (methylene blue, rhodamine B, crystal violet, and Orange II) and antibiotics (e.g., tetracycline) under visible-light irradiation, achieving final degradation efficiencies higher than 90%. The excellent performance is attributed to the synergistic effect of the ordered interface provided by the PNF template, the stabilization and uniform dispersion facilitated by GO, and the mechanically robust 3D scaffold constructed by MCC. This work provides an efficient and sustainable strategy for designing functional hybrid aerogels and lays a foundation for their application in water treatment and environmental remediation.