A controllable floating pDA-PVDF bead for enhanced decomposition of H2O2 and degradation of dyes

Fe species/biochar fiber composite (FCF) has become one of promising materials for wastewater treatment via heterogeneous photo-Fenton reaction. However, the powdered form always suffers from inefficient recovery and inherent iron loss, limiting their practical application. Herein, we provide an alternative polydopamine (pDA)-modified PVDF bead as excellent photo-Fenton support for immobilizing FCF by phase inversion, which not only limits the loss of iron ions, but also promotes the H 2 O 2 decomposition. Moreover, these beads can float on the wastewater due to their inner structure, favoring the harvest of light. Thanks to these unique characteristics, these beads displayed almost 100% of decolorization in self-designed flowing dyes wastewater systems. Particularly, the self-floating beads structure makes catalysts be easily recovered and maintains long-term high activity, which significantly eliminates the inherent challenge of powdered catalyst (e.g. FCF) based degradation process. This work provides an “easily applicable platform” for large-scale applications of powdered photo-Fenton catalyst in wastewater treatment.