Accelerated Fe(III)/Fe(II) cycle for ultrafast removal of acetaminophen by a novel W18O49 co-catalytic Fe3+/H2O2 fenton-like system

Abstract

The traditional Fenton reaction always encounters the restriction that the solution pH needs to be strictly regulated, and Fe2+ is easy to self-decompose but not easy to regenerate. Fe3+ is relatively stable but its reaction with H2O2 is super-restricted. A novel strategy for the co-catalytic effect of W18O49 on the enhancement of Fe3+/H2O2 reaction activity was presented in this study. The W18O49/Fe3+/H2O2 system achieved a 94% acetaminophen (ACE) degradation rate within 5 min, which was much higher than the Fe3+/H2O2 system (48%), and W18O49 also showed excellent repeatability. Quenching experiment and ESR proved that the removal of ACE mainly depended on 1O2 (leading role) and •OH, which was different from the previously reported Fenton/Fenton-like system dominated by •OH. Accelerated Fe2+/Fe3+ cycling controlled by variational W4+/W6+ and intermediate •OH stabilization by oxygen vacancy for enhancing the breaking of O-O bond in H2O2 to produce more radicals was the dual driving force in the W18O49/Fe3+/H2O2 system for enhanced oxidation activity. The W18O49/Fe3+/H2O2 system has favorable tolerance to a wide range of pH and anions, which provides a feasible strategy for the practical application of the Fenton-like system.