Efficiently Recyclable Fe-Doped ZnO/Bacterial Cellulose-Based Composite Aerogel for Photocatalytic Degradation of Methylene Blue Under Visible Light

Excellent photocatalytic performance and recyclability are crucial for the long-term use of the photocatalyst. In this study, 5 mol% Fe doped zinc oxide (ZF5), was freeze-dried with bacterial cellulose (BC)/sodium alginate (SA) solution to fabricate a novel composite aerogel capable of degrading methylene blue (MB) under visible light. Ca²⁺ crosslinking and hydrophobic modifications were adopted to strengthen the aerogel skeleton and enhance the cycling photocatalytic activity, meanwhile, making the aerogel floatable persistently. The influences of pH, ZF5 dosage, and initial solution concentration on MB degradation were investigated. Benefiting from the synergy between the components and the combined modification, the optimum composite aerogel exhibits photocatalytic efficiency of up to 97.4% at an initial MB concentration of 20 mg/L within an irradiation time of 80 min. In addition, it exhibits a degradation efficiency of 79.7% even after 8 cycles, showing great potential in visible-light-driven degradation of MB.