Reusable cellulose aerogels conjugated with ZnO/Ag2O heterojunctions for organic dye removal via synergistic adsorption/Fenton-like catalysis

With industrialization progressing rapidly, the discharge of printing and dyeing wastewater has risen significantly. This wastewater contains organic dyes like methylene blue (MB), posing a significant risk to the environment and human health. This study reports the successful fabrication of a multifunctional magnetic aerogel (ZACPF) with synergistic adsorption and catalytic properties. The aerogel was prepared by incorporating ZnO/Ag 2 O heterojunctions into a dual-network hydrogel formed by cross-linking cellulose nanofibers (CNFs) and polyvinyl alcohol (PVA), followed by in-situ loading of magnetic Fe 3 O 4 . Experimental results showed that the aerogel has excellent adsorption performance for both cationic (416.34–984.52 mg/g) and anionic dyes (993.83–1025.95 mg/g) at 25 °C with pH 6.5. Characterization analyses confirm that the adsorption mechanism involves multi-site interactions, including electrostatic attraction, hydrogen bonding, and pore filling. When combined with H 2 O 2 , its degradation efficiency for MB at 20 mg/L was significantly enhanced, reaching 85.15% within 120 min at 25 °C with pH 6.5. The band alignment mechanism also facilitated the effective separation of photogenerated carriers, enabling a MB degradation rate of 98.91% under visible light within 60 min. Furthermore, the aerogel exhibited excellent recyclability, maintaining over 79.2% of its initial degradation efficiency after five cycles. In conclusion, this study presents an innovative strategy for developing high-performance aerogel catalysts to treat dye-contaminated water.