Optimizing Strategies of in Situ Loading Photocatalysts in Aramid Nanofiber Aerogels: Harnessing Internal/External Synergistic Photocatalysis for Improving Degradation Efficiency of Pollutants

Construction of aerogel-based composite photocatalytic materials is an effective way to completely eliminate pollutants in water. However, uniform dispersion of photocatalyst nanoparticles in porous aerogels and how to achieve efficient adsorption/photocatalysis synergy still face challenge. In this study, we have successfully addressed the challenge of achieving uniform loading of TiO 2 photocatalyst nanoparticles in aramid nanofiber (ANF) aerogels using silica aerogel powder (SAP)-assisted dispersion, which significantly broadens the spectral response range of TiO 2 . The as-prepared ANF composite aerogel fibers exhibited excellent properties, such as low shrinkage (13.7%), high porosity (94.8%), and a high specific surface area (238.033 m 2 /g). Moreover, the as-prepared ANF/SAP/TiO 2 @TiOSO 4 (M-TAST) composite aerogel film by using TiOSO 4 aqueous solution as coagulation bath achieved a synergistic effect of internal/external photocatalysis, with further improved carrier separation and migration ability, and effectively inhibited the recombination of photogenerated electron–hole pairs. Thus, the as-prepared ANF-based composite aerogel film demonstrated excellent adsorption/photocatalytic degradation of tetracycline and organic dyes. In particular, the degradation efficiency of crystal violet (CV) reached 98% in 10 min, significantly outperforming P25. Additionally, the film also exhibited good photocatalytic performance within the pH range of 2–10 and excellent recycling stability. This unique photocatalyst loading strategy is crucial for achieving adsorption and internal/external photocatalysis synergy, and the constructed M-TAST composite aerogel film shows a promising prospect for application in environmental purification.