Hybrid Polymeric Nanostructures Stabilized by Ferric Cations with Photo-Fenton Performance: Implications for Recoverable Multicatalyst Design

Iron ions, as traditional high-efficiency Fenton reaction catalysts, react with hydrogen peroxide to generate hydroxyl radicals, thereby degrading organic pollutants in wastewater. However, in aqueous solutions, iron ions have a poor chemical stability and are therefore difficult to recover from the reaction medium. We propose that their complexation with double-hydrophilic block copolymers can lead to the formation of nanocatalysts with improved chemical and colloidal stability. Iron ions were added at different molar ratios to a solution of a double-hydrophilic block copolymer, that is, poly(ethylene oxide)-block-poly(acrylic acid) to lead to the formation of colloidal structures. Spontaneous formation of highly monodisperse micelles with a hydrodynamic diameter around nm occurs when the charge ratio between the positive iron ions and the negative PAA polyanions is close to one. By combining several techniques, a precise description of the core-shell architecture was achieved. These structures are chemically stable in the pH range of 3-7 and have been successfully used as photo-Fenton catalysts through the degradation of naphthol blue black. Compared to the traditional homogeneous Fenton reaction, these colloidal structures have improved chemical and colloidal stabilities as well a higher recyclability.

Automated summary

Iron ions, as traditional Fenton reaction catalysts, have poor stability in aqueous solutions. Researchers have developed nanocatalysts with improved stability by complexing iron ions with double-hydrophilic block copolymers. These colloidal structures are chemically stable in a pH range of 3-7 and can be used for degrading organic pollutants in wastewater.