Integration of Atomically Dispersed Cu–N₄ Sites with C₃N₄ for Enhanced Photo-Fenton Degradation over a Nonradical Mechanism

Abstract

Photo-Fenton degradation as a promising strategy for antibiotic wastewater treatment attracted extensive attention, while the unsatisfactory catalytic performance vitally limits its industrial application. Herein, we demonstrate that confining atomically dispersed Cu into C3N4 (Cu–C3N4) enables fast H2O2 activation and efficient separation of photogenerated electron–hole pairs, resulting in a dramatic improvement of the degradation efficiency of the Photo-Fenton reaction. Photo-Fenton degradation of ciprofloxacin (CIP) was close to 99% within 30 min over optimized Cu–C3N4, corresponding to a pseudo-first-order rate constant of ∼0.0978 min–1, almost 4.5 times higher than pure C3N4 counterpart. The electron paramagnetic resonance, quenching experiments, and X-ray absorption fine structure results reveal that the superior Photo-Fenton catalytic performance is attributed to a nonradical reaction pathway, where the H2O2 is activated by the formation of the OCu–N4O intermediate. The advanced catalyst as well as the refreshing H2O2 activation mechanism are of profound significance for the materials design in the wastewater treatment field.

Push–Pull Engine─Electron Pumping by Anchored Ligands over ZnO/C: Boosting Photo-Fenton-Like Catalysis without Additional Oxidants

“…Hydrogen peroxide (H 2 O 2 ) is an environment friendly oxidant that exhibits strong oxidizing properties with benign byproducts. , Thus, it is useful in various chemical processes including the Fenton process. , However, storage, transportation, and handling of concentrated H 2 O 2 is risky . In addition, these processes require regular replenishment of H 2 O 2 , as the high concentration leads to the rapid activation of H 2 O 2 to the short-lived ROS .…”

Ferrate(VI) Activation with Nanoconfined Cu–Mg Sites for Water Treatment: Selective Cu(III) Production via Support-Dependent Redox Catalysis

“…3,4,15 For instance, electrically conductive g-C 3 N 4 as a support enhanced the efficiency of confined Cu in Cu−N sites in photo-Fenton oxidation. 16 Inorganic supports such as SiO 2 and Al 2 O 3 modified the MSIs in Fe-based catalysts, tailoring the reactivity of supported Fe toward H 2 O 2 . 17 The confinement of two metal NPs (e.g., Co and Fe) in SiO 2 and montmorillonite as hosts facilitated their electron exchange, enabling a synergistic contribution to peroxide activation.…”

“…Inspired by significantly improved performance of metal NPs in nanoconfined electron transfer processes, NPs encapsulated in the nanospaces of host materials have often been applied to generate reactive oxidative radicals via one-electron reduction of inorganic peroxides, such as persulfate, H 2 O 2 , and peracetate. ,, For instance, electrically conductive g-C 3 N 4 as a support enhanced the efficiency of confined Cu in Cu–N sites in photo-Fenton oxidation . Inorganic supports such as SiO 2 and Al 2 O 3 modified the MSIs in Fe-based catalysts, tailoring the reactivity of supported Fe toward H 2 O 2 .…”

The Use of Iron-Doped Anatase TiO2 Nanofibers for Enhanced Photocatalytic Fenton-like Reaction to Degrade Tylosin

“…Heterogeneous Fenton-like photocatalysts play a decisive role in this oxidation process [13][14][15][16]. TiO 2 , possessing a band gap of about 3.0-3.2 eV, has been extensively investigated as a photocatalyst to degrade pollutants because of its bio-safety, low price, and chemical stability [17,18].…”