Oxygen-Centered Organic Radicals-Involved Unified Heterogeneous Self-Fenton Process for Stable Mineralization of Micropollutants in Water.

ABSTRACT

Removing organic micropollutants from water through photocatalysis is hindered by catalyst instability and substantial residuals from incomplete mineralization. Here, a novel water treatment paradigm, the unified heterogeneous self-Fenton process (UHSFP), which achieved an impressive 32% photon utilization efficiency at 470 nm, and a significant 94% mineralization of organic micropollutants-all without the continual addition of oxidants and iron ions is presented. In UHSFP, the active species differs fundamentally from traditional photocatalytic processes. One electron acceptor unit of photocatalyst acquires only one photogenerated electron to convert into oxygen-centered organic radical (OCOR), then spontaneously completing subsequent processes, including pollutant degradation, hydrogen peroxide generation, activation, and mineralization of organic micropollutants. By bolstering electron-transfer capabilities and diminishing catalyst affinity for oxygen in the photocatalytic process, the generation of superoxide radicals is effectively suppressed, preventing detrimental attacks on the catalyst. This study introduces an innovative and cost-effective strategy for the efficient and stable mineralization of organic micropollutants, eliminating the necessity for continuous chemical inputs, providing a new perspective on water treatment technologies.