Magnetic CuFe Research Articles

Synergistic magnetic Cu-Fe catalysts on N-doped biochar for efficient alkali lignin catalytic depolymerization into monophenols

Alkali lignin, a major by-product of papermaking, poses disposal challenges, hindering the full valorization of lignocellulose in sustainable biorefineries. One-pot lignin catalytic depolymerization (LDP) in water offers a promising route for producing valuable phenolic compounds. This study reports the successful synthesis of in-situ N-doped biochar supported CuxFey catalysts (CuxFey/N-BC) via a one-step carbothermal reduction method, enabling LDP in water without the need for external hydrogen, additives, alcohol solvent, or co-catalysts. Notably, the Cu5Fe1/N-BC could achieve remarkable catalytic performance under mild reaction conditions (280 °C, 6 h, 18 mL water), yielding 80.84±2.23 mg/g of monophenol, 56.17±1.32 % of bio-oil, and a lignin conversion rate of 80.66±0.73 %. This significantly surpassed the performance of monometallic catalysts and bare biochar. The synergistic effects of intermetallic interactions and nitrogen doping were proposed to create abundant active sites and rich pore structures, promoting efficient LDP reactions. Furthermore, the Cu5Fe1/N-BC exhibited excellent recyclability, with minimal activity loss (2.79 %) per cycle, due to its strong magnetism and favorable interactions. Mechanism investigation revealed that the Cu5Fe1/N-BC efficiently cleaved the C-O and C-C bonds in lignin, and led to the targeted production of guaiacyl phenols. This study provides valuable insights and practical strategy for valorizing lignin into valuable chemicals, advancing its utilization in various applications.

Strategic One-Pot Synthesis of 1,2,3-Triazole-Based Dihydropyrimidinone Hybrids Using Magnetic CuFe2O4 NPS as Heterogeneous Catalyst and Their DFT, Molecular Docking Studies

A rapid and enormously professional new-flanged 3,5-disubstituted triazole derivatives were synthesized by the one-pot five-component condensation reaction in the course of transesterification followed by the Biginelli/Click reaction in aqueous medium using magnetic CuFe2O4 NPs as heterogeneous catalyst beneath ultrasonic acceleration in aqueous medium. The synthesized 3,5-disubstituted triazole derivatives were finely characterized and the characterized desired target molecules were employed for the quantum chemical calculations for each reactant and product have been well thought-out using density functional theory. Furthermore, the molecular docking and ADMET revision of all the derivatives have been achieved as digestive enzyme and Cathepsin-B inhibitors and their connections with BSA to treat different diseases.

Enhanced mercury removal performance of Cu-Fe binary oxide sorbents modified by non-thermal plasma

In this work, magnetic Cu-Fe binary oxide (CF) sorbents synthesized by sol − gel method are modified by oxygen non-thermal plasma for efficient removal of elemental mercury (Hg0) from coal-fired flue gas. Sample characterization indicates that plasma treatment has very little impact on the physical properties, magnetization characteristics, and crystalline phases of CF sorbents. But the content of Fe3+, Cu2+, and lattice oxygen in CF sorbents are significantly improved after plasma treatment. Mercury adsorption experiments suggest that the modified sorbents show higher Hg0 removal efficiency in comparison with raw sorbents, and longer treatment time leads to higher Hg0 removal efficiency. The effect of plasma discharge power (32–96 VA), discharge atmosphere (N2, air, 50% N2 + 50% O2, and O2), and reaction temperature (50–350 °C) on mercury removal performance are also explored in a fixed-bed reactor. The presence of O2, NO, and HCl promote Hg0 removal. SO2 and H2O suppress Hg0 removal, but O2 addition can obviously weaken such inhibitory effects. Both experimental results and kinetic model indicate that chemisorption is the decisive factor for Hg0 removal over CF sorbents. Moreover, the mechanism of Hg0 removal over the modified CF sorbents is also investigated. The results indicate that Fe2O3 and CuO serving as active sites are greatly consumed in Hg0 removal process. The multiple regeneration cycles testify that the combination of thermal desorption and non-thermal plasma treatment can realize the efficient regeneration of CF sorbents.

Thermally Reduced Soft Magnetic CuFe Nanoparticles for High-Performance Electrical Devices

Developing economically soft magnetic materials for high-performance electrical devices is indispensable. Here, we present the structural and magnetic properties of thermally reduced soft CuFe nanoparticles. The fcc cubic structure of iron-rich Cu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">37</sub> Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">63</sub> and their composition was confirmed by Rietveld refinement. Cu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">37</sub> Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">63</sub> nanoparticles exhibited high saturation magnetization and coercivity of 127 emu/g (142 emu/g) and 4.3 Oe (31 Oe), respectively, at 300 K (5 K). They showed transitions at ~34 and ~249 K due to the Kondo temperature of CuFe and minor fraction of CuFe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> , respectively. The exchange coupling between Cu and Fe was not significant, as demonstrated by field-cooled magnetization curves at 5 K. The magnetocaloric effect (MCE) in the range of fields and temperatures was estimated whereas the maximum MCE of -8.71 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup> J.kg <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> .K <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> was achieved at 222 K. These soft magnetic materials, which exhibited stable high saturation magnetization with less heating effect during magnetization and demagnetization cycles, would be suitable candidates for magnetic applications.

Prussian blue analogue derived magnetic Cu-Fe oxide as a recyclable photo-Fenton catalyst for the efficient removal of sulfamethazine at near neutral pH values

The presence of antibiotics in aquatic environments has attracted global concern. Heterogeneous photo-Fenton process is an attractive yet challenging method for antibiotics degradation, especially when such a process can be operated at neutral pH values. In this work, a new magnetic Cu-Fe oxide (CuFeO) was developed as the heterogeneous photo-Fenton catalyst through a facile two-step method. The obtained CuFeO particles were found to be more efficient to activate H2O2 into radicals (OH and O2−) than Cu-Fe Prussian blue analogue (Cu-Fe PBA, the precursor) at near neutral conditions. The removal rate of sulfamethazine (SMZ) in CuFeO/H2O2/Vis system was much higher than those in CuO/H2O2/Vis and Fe3O4/H2O2/Vis systems. It was observed that nearly complete removal of SMZ from ultrapure water, river water and tap water can be achieved in 30 min in CuFeO/H2O2/Vis system. The influence of different process parameters on the SMZ degradation efficiency was then examined and the catalytic stability of CuFeO was also tested. The SMZ degradation intermediates during the process were analyzed and the degradation pathway was proposed based on LC–MS results. The mechanisms for H2O2 activation were studied by X-ray photoelectron spectrum analysis, radical scavenging and electron spin-trapping experiments. It is suggested that the synergistic effect among photo-induced electrons, Cu and Fe in CuFeO exhibits excellent performance in the catalytic activation of H2O2. This work is expected to provide useful information for the design and synthesis of bimetallic oxide for heterogeneous photo-Fenton reactions.

Magnetically Separable Ag/CuFe2O4 /Reduced Graphene Oxide Ternary Nanocomposite with High Performance for the Removal of Nitrophenols and Dye Pollutants from Aqueous Media

In this work, a novel ternary magnetic nanocomposite namely Ag/CuFe2O4/rGO was produced by a facile solvothermal route. The reduction of graphene oxide (GO) to reduced form (rGO) and the in-situ deposition of CuFe2O4 and Ag nanoparticles on rGO occurred simultaneously in a one-pot reaction. The structure, composition and morphology of the as-prepared nanocomposite were characterized by FT-IR, XRD, VSM, FESEM, EDX, TEM, and BET analyses. The results indicated that the Ag and CuFe2O4 nanoparticles were successfully loaded on the surface of rGO. The catalytic performance of the Ag/CuFe2O4/rGO nanocomposite was evaluated for the reduction of nitroarenes to corresponding amines in the presence of sodium borohydride (NaBH4) as a reducing agent. The nanocomposite exhibited the high performance in the reduction of the reduction of nitroarenes with 100% conversion within 10-30 min. The catalytic activity of the Ag/CuFe2O4/rGO was enhanced compared with Ag/CuFe2O4, Ag/rGO and CuFe2O4/rGO samples due to easier electron transfer process. Furthermore, the adsorption data revealed that cationic methylene blue (MB) dye could be removed almost completely on the Ag/CuFe2O4/rGO composite within 2 min and the composite could also selectively adsorb MB from the mixed solution with anionic methyl orange (MO). Due to the existence of magnetic CuFe2O4 nanoparticles, the Ag/CuFe2O4/rGO nanocomposite can be magnetically separated and reused without any change in structure and performance.

Magnetic CuFe2O4 and Fe3O4 Nanoparticles Catalyzed Diacetoxylation of Alkenes and 1,2‐Oxyacetoxylation of Terminal Alkynes Using PhI(OAc)2 as Oxidant

AbstractMagnetically retrievable CuFe2O4 and Fe3O4 nanoparticles as efficient catalysts for selective syn diacetoxylation of alkenes have been achieved using PhI(OAc)2 as oxidant under mild conditions. In addition, by using this protocol, different kinds of terminal alkynes were efficiently converted into the corresponding α‐acetoxy ketones. The catalysts were reused with consistent activity up to five cycles. To the best of our knowledge, CuFe2O4 and Fe3O4 heterogeneous catalyzed diacetoxylation of alkenes has not been studied so far.

Removal of Methyl Blue by Magnetic CuFe&lt;SUB&gt;2&lt;/SUB&gt;O&lt;SUB&gt;4&lt;/SUB&gt; Nanoparticles Prepared via the Novel Solution Combustion Process

Removal of Methyl Blue by Magnetic CuFe&lt;SUB&gt;2&lt;/SUB&gt;O&lt;SUB&gt;4&lt;/SUB&gt; Nanoparticles Prepared via the Novel Solution Combustion Process

ChemInform Abstract: Magnetic CuFe2O4 Nanoparticles: A Retrievable Catalyst for Oxidative Amidation of Aldehydes with Amine Hydrochloride Salts.

AbstractThe use of amines as their salts is crucial.

ChemInform Abstract: A Novel Sustainable Strategy for the Synthesis of Phenols by Magnetic CuFe2O4‐Catalyzed Oxidative Hydroxylation of Arylboronic Acids under Mild Conditions in Water.

Abstract A novel sustainable strategy for the synthesis of phenols has been developed using inexpensive, readily available, air-stable, and recyclable CuFe2O4 nanoparticles as the catalyst, and the corresponding substituted phenols were obtained in moderate to good yields by oxidative hydroxylation of arylboronic acids in water. Importantly, a ligand or an additive was not necessary. The catalyst was completely recoverable with an external magnet and could be reused six times without significant loss of catalytic activity.

Production of Sulfate Radical from Peroxymonosulfate Induced by a Magnetically Separable CuFe2O4 Spinel in Water: Efficiency, Stability, and Mechanism

A simple, nonhazardous, efficient and low energy-consuming process is desirable to generate powerful radicals from peroxymonosulfate (PMS) for recalcitrant pollutant removal. In this work, the production of radical species from PMS induced by a magnetic CuFe(2)O(4) spinel was studied. Iopromide, a recalcitrant model pollutant, was used to investigate the efficiency of this process. CuFe(2)O(4) showed higher activity and 30 times lower Cu(2+) leaching (1.5 μg L(-1) per 100 mg L(-1)) than a well-crystallized CuO at the same dosage. CuFe(2)O(4) maintained its activity and crystallinity during repeated batch experiments. In comparison, the activity of CuO declined significantly, which was ascribed to the deterioration in its degree of crystallinity. The efficiency of the PMS/CuFe(2)O(4) was highest at neutral pH and decreased at acidic and alkaline pHs. Sulfate radical was the primary radical species responsible for the iopromide degradation. On the basis of the stoichiometry of oxalate degradation in the PMS/CuFe(2)O(4), the radical production yield from PMS was determined to be near 1 mol/mol. The PMS decomposition involved an inner-sphere complexation with the oxide's surface Cu(II) sites. In situ characterization of the oxide surface with ATR-FTIR and Raman during the PMS decomposition suggested that surface Cu(II)-Cu(III)-Cu(II) redox cycle was responsible for the efficient sulfate radical generation from PMS.

ChemInform Abstract: Magnetic CuFe2O4 Nanoparticles as an Efficient Catalyst for C—O Cross‐Coupling of Phenols with Aryl Halides.

AbstractBest results are achieved with iodides whereby, substrates with electron‐withdrawing groups like the nitro derivative (Ib) give the desired products even in the absence of the catalyst system.

Magnetic CuFe2O4 Nanoparticles as an Efficient Catalyst for CO Cross‐Coupling of Phenols with Aryl Halides

Ultra magnets: Magnetic CuFe2O4 nanoparticles have been simply prepared and applied as a catalyst in the CO cross-coupling of phenols and aryl halides to form diaryl ethers, an important structural motif in many products, industrial polymers, and biologically active compounds. The catalyst is recycled without a significant loss of catalytic activity.

Preparation and shape control of multiple-arm magnetic particles

Multiple-arm magnetic CuFe 2O 4 particles have been synthesized via a simple one-step solution-phase route at the presence of ethylene glycol (EG) ligands, which plays a key role for the shape control of the particle. At low EG content, hexa-arm CuFe 2O 4 particles with average arm diameter 50 nm and length 400 nm were obtained. Furthermore, a possible mechanism of shape evaluation process of these magnetic particles is discussed.

Removal of azo-dye Acid Red B (ARB) by adsorption and catalytic combustion using magnetic CuFe2O4 powder

The effectiveness of magnetic CuFe2O4 powder as adsorbent/catalyst for the removal of azo-dye Acid Red B (ARB) from water by adsorption and subsequent catalytic combustion was studied. Magnetic CuFe2O4 powder showed excellent adsorption properties towards ARB at pH<5.5, and it could be conveniently recovered by magnetic separation technology after adsorption. The combustion decomposition of ARB in the presence or absence of CuFe2O4 was studied by a system for thermal degradation studies (STDS) and in situ FTIR. The results indicated that different reactive pathways existed for the combustion under different conditions. In the presence of CuFe2O4, the temperature needed for oxidation reaction and for combustion was 150 and 300°C, respectively. The reaction products were observed to be SO2, CO2, H2O, and nitrate. There was neither volatile organic compound (VOCs) emitted to atmosphere during reaction nor organic matter deposited on the surface of CuFe2O4 after the combustion. Comparatively, in the absence of CuFe2O4, the oxidation and combustion of ARB required a higher temperature (300 and 500°C, respectively) and produced a lot of toxic organic compounds emitted to atmosphere besides SO2, CO2 and H2O during the reaction. In addition, sulfate was generated instead of nitrate. The experiments of adsorption–combustion cycles demonstrated that there was no evident change in adsorption properties and catalytic activity of magnetic CuFe2O4 powder after seven cycles.