Covalent Organic Framework-Functionalized Magnetic CuFe2O4/Ag Nanoparticles for the Reduction of 4-Nitrophenol

Abstract

In this work, magnetic CuFe2O4/Ag nanoparticles activated by porous covalent organic frameworks (COF) was fabricated to evaluate the heterogenous reduction of 4-nitrophenol (4-NP). The core-shell CuFe2O4/Ag@COF was successfully prepared by polydopamine reduction of silver ions on CuFe2O4 nanoparticles, followed by COF layer condensation. By integrating the intrinsic characteristics of the magnetic CuFe2O4/Ag core and COF layer, the obtained nanocomposite exhibited features of high specific surface area (464.21 m2 g−1), ordered mesoporous structure, strong environment stability, as well as fast magnetic response. Accordingly, the CuFe2O4/Ag@COF catalyst showed good affinity towards 4-NP via π-π stacking interactions and possessed enhanced catalytic activity compared with CuFe2O4/Ag and CuFe2O4@COF. The pseudo-first-order rate constant of CuFe2O4/Ag@COF (0.77 min−1) is 3 and 5 times higher than CuFe2O4/Ag and CuFe2O4@COF, respectively. The characteristics of bi-catalytic CuFe2O4/Ag and the porous COF shell of CuFe2O4/Ag@COF made a contribution to improve the activity of 4-NP reduction. The present work demonstrated a facile strategy to fabricate COF-activated nano-catalysts with enhanced performance in the fields of nitrophenolic wastewater treatment.

Covalent Organic Frameworks in Catalytic Organic Synthesis

“…Similarly, Liang's group also reported a work that took the core‐shell strategy and introduced (TAPB‐DMTP‐COF) as the shell, magnetic PVP‐modified CuFe 2 O 4 /Ag NPs as the core to catalyze the reduction reaction (Scheme 36). [82] In this work, both CuFe 2 O 4 NPs and Ag NPs helped to transfer the electrons and the CuFe 2 O 4 NPs prevented Ag NPs from aggregation. COFs also functioned as the platform to stabilize metal NPs and supplied additional channels to transfer substrates.…”

Covalent‐Organic Framework Composites: A Review Report on Synthesis Methods

“…Mixed metals oxides with nanoparticles e. g . NiFe 2 O 4 [135] and CuFe 2 O 4 [136] NPs have also been reported. In most cases the magnetic COF composites contains iron oxide, Fe 3 O 4 .…”

Covalent Organic Framework Composites: Synthesis and Analytical Applications

“…Magnetic nanoparticles (NPs) are attractive for a wide range of applications due to their remarkable magnetic properties, stability, biocompatibility, and fast separation using an external magnetic field [23]. The majority of magnetic COF composites contain iron oxide, Fe 3 O 4 , as the magnetic NP, although a few other examples with NiFe 2 O 4 [24] and CuFe 2 O 4 [25] NPs have been reported. Superparamagnetic iron oxide NPs are Fe 3 O 4 particles with cores below 100 nm in diameter [26].…”