In-situ constructing robust cellulose nanocomposite hydrogel network with well-dispersed dual catalysts for the efficient, stable and recyclable photo-Fenton degradation

The hydrogel supported catalyst is explored as an efficient strategy for water remediation due to its combination of absorption and degradation, while it remains great challenge to prepare highly dispersed multi-component catalyst. Herein, cellulose-based hydrogel containing dual-component catalysts was fabricated via in-situ synthesis and mineralization, where the cellulose network containing –OH and –COOH provided a good platform for achieving highly dispersed TiO₂ and Fe₃O₄. To the methylene blue (MB) solution (c₀ = 20 mg/L), the TiO₂/Fe₃O₄ nanocomposite hydrogel displayed a high removal ratio of 97.5% in 60 min by photo-Fenton reaction. Interestingly, owing to the ionic hydrogel feature, the degradation efficiency maintained over 97.2% in a broad initial pH range from 4 to 7, And the hydrogel could effectively hold the contaminants with nearly no leakage and retained the removal ratio of 98.0% after 5 degradation cycles. This study provides new insights into the in-situ synthesis of multi-component catalyst in hydrogels for efficient, stable, and safe water treatment.