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ABSTRACT A3 coupling reaction is a multicomponent reaction (MCR) involving aryl aldehydes, phenyl acetylenes and amines to synthesize a variety of biologically active propargylamine derivatives. Herein, we report the preparation of cube‐shaped CuFe2O4 nanoparticles (NPs) via the hydrothermal method in the presence of Lantana camara flower (LCF) extract to use them as catalysts to synthesize propargylamine derivatives. X‐ray diffraction study confirms the formation of CuFe2O4 NPs with cubic spinel structures. In the presence of LCF extract, cube‐shaped CuFe2O4 NPs are formed predominantly irrespective of the type of alkali used as the hydrolyzing agent. However, a mixture of nearly spherical and cube‐shaped particles has been formed in the absence of additives. The synthesized CuFe2O4 NPs exhibit superparamagnetic behaviour and are magnetically ordered. The synthesized cube‐shaped CuFe2O4 NPs exhibit excellent catalytic activity in the A3 coupling reaction between benzaldehyde, piperidine and phenylacetylene to give propargylamine with a yield of 90% under the optimum conditions. The catalyst is highly stable and magnetically retrievable facilitating reusability for up to five cycles without considerable loss of catalytic activity. The protocol is suitable for the synthesis of a diverse range of propargylamine derivatives with moderate to excellent yield. [ABSTRACT FROM AUTHOR]

Magnetic CuFe2O4 was prepared with the modified sol–gel method and used for enhanced peroxymonosulfate (PMS) activation and ofloxacin (OFL) degradation. The OFL could almost degrade within 30 min at a catalyst dosage of 0.66 g/L, PMS concentration of 0.38 mM, and initial pH of 6.53 without adjustment, using response surface methodology (RSM) with Box-Behnken design (BBD). In the CuFe2O4/PMS system, the coexisting substances, including CO32−, NO3−, SO42−, Cl− and humic acid, have little effect on the OFL degradation. The system also performs well in actual water, such as tap water and surface water (Mei Lake), indicating the excellent anti-interference ability of the system. The cyclic transformation between Cu(II)/Cu(I) and Fe(III)/Fe(II) triggers the generation of active radicals including SO4•−, •OH, •O2− and 1O2. The OFL degradation pathway, mainly involving the dehydrogenation, deamination, hydroxylation, decarboxylation and carboxylation processes, was proposed using mass spectroscopy. Moreover, the toxicity assessment indicated that the end intermediates are environmentally friendly. This study is about how the CuFe2O4/PMS system performs well in PMS activation for refractory organic matter removal in wastewater. [ABSTRACT FROM AUTHOR]

The transition bimetallic oxide catalyst demonstrates the ability to activate peroxymonosulfate (PMS), generating oxidative active groups and facilitating room temperature reactions, all at a relatively low cost. The freeze-drying method was successfully utilized to obtain CuFe2O4 to boost peroxymonosulfate activation to degrade rhodamine-B dye. The catalyst underwent characterization through XRD and SEM. The impact of various reaction parameters, such as initial pH value and PMS dosage on the degradation of rhodamine-B, was examined. The results revealed that the CuFe2O4 catalyst obtained via freeze-drying method as the precipitant exhibited uniform and regular particle characteristics, remarkable crystallization degree, high purity, enormous specific surface area, and an absence of impurity functional groups. Additionally, the prepared CuFe2O4 material showcased enhanced catalytic performance. To carry out the catalysis process, the rhodamine-B concentration was set at 20 mg·L−1, with an amount of 200 mg·L−1 of CuFe2O4 material used. The optimal pH was determined to be 9.0, while the ideal PMS concentration was found to be 1.0 mmol·L−1. Under these specific conditions, an impressive 99% degradation rate of rhodamine-B was achieved in just 27 min of catalysis. [ABSTRACT FROM AUTHOR]

For the on-line stable detection of TEA, mixed potential gas sensor based on GDC (gadolinium doped cerium oxide, Ce 0.8 Gd 0.2 O 1.95) solid electrolyte and MFe 2 O 4 (M = Ni, Cu, Zn) sensing electrode has been fabricated in this work. The influence of element type and sintering temperature of the sensing materials on the sensing performance were mainly discussed, the sensor manufactured with CuFe 2 O 4 sintered at 800 °C generates the highest response (−50.7 mV) to 20 ppm TEA compared with other sensors. The response value changed proportionally with the logarithm of TEA concentration, with the sensitivity of −21.9 and −43.6 mV/decade in the range of 0.5–5 and 5–100 ppm, respectively. The sensor exhibited excellent repeatability towards 2 and 10 ppm TEA for 7 continuous tests, and great selectivity for 10 various gases. Moreover, the sensor also demonstrated good moisture resistance and terrific long-term stability at 500 °C for 30 days continuous work. Based on the excellent sensing properties, this work supplied a stable TEA sensor fabricated with CuFe 2 O 4 sintered at 800 °C, which has a great potential application prospect for the accurate detection towards TEA. [Display omitted] [ABSTRACT FROM AUTHOR]

Heterostructures of CuFe2O4@NH2-MIL-88B (Fe) were effectively synthesized and utilized as an effective catalyst under visible light and oxidation conditions for the synthesis of quinazolinones. At room temperature, good to excellent yields of the desired products were obtained. In addition, the composite heterostructures that were created showed a higher level of photocatalytic activity when exposed to visible light compared to both CuFe2O4 and NH2-MIL-88B (Fe) individually. In comparison with CuFe2O4 and MIL-88B (Fe), the absorption peak of CuFe2O4/MIL has increased. Increasing visible light absorption could lead to an increase in electron–hole pair formation, which would improve photocatalytic activity. Furthermore, the incorporation of CuFe2O4 to the NH2-MIL 88B (Fe) surface results in a significant reduction in photoluminescence emission intensity. Moreover, from the perspective of sustainable chemistry, CuFe2O4@NH2-MIL-88B (Fe) demonstrated good recyclability, being recycled six times with little to no loss in catalytic efficacy. [ABSTRACT FROM AUTHOR]

The microwave ignition holds potential in the ignition of weapons due to its simple structure, non-contact property, and simultaneous ignitions of large area. However, the long ignition delay time of the current ignition agents cannot meet the microwave weaponry advancements. To address the issues, a microwave sensitive oxide-CuFe 2 O 4 (CUFO) which was firstly discovered to be easily ignited by microwaves compared many ferrites, was coupled with Ti nanoparticles (n-Ti) to form Ti/CUFO microwave ignition agents by electrostatic spray granulation. The characterization of microwave ignition, volumetric combustion, burning rate and DSC were used to determine its ignition delay time and the energy release properties. It indicates that the microwave sensitivity, maximum peak pressure and pressure pressurization rate of Ti/CUFO first increases and then decreases with the promoting content of n-Ti. The Ti/CUFO at Φ = 3.5 exhibits the lowest ignition delay time by 79.24 ms compared to the 98.7 ms of n-Ti, meanwhile, its maximum peak pressure and pressurization rate reach the highest by 338.54 kPa and 8.57 kPa/ms, respectively. The DSC results indicate that Ti/CUFO exhibits much lower reaction peak temperature by 320–335 °C compared to 488 °C of n-Ti, which suggests Ti-CUFO reaction maybe much easier be activated. The dielectric loss of n-Ti and CUFO under strong electric field transfer the energy of microwaves to heat, reaching to its reaction temperature. The XPS and XRD results of CUFO after microwave radiation disclosing the crystal transition, formation of divalent iron and oxygen vacancies, as well as the released bright light under microwave radiation, suggest the thermal breakdown mechanism of CUFO. When Ti/CUFO exposes into microwaves, CUFO generates oxygen vacancies due to heat loss and n-Ti is dielectric heated, followed by the generated oxygen reacting with n-Ti, improving the combustion performance of n-Ti. This result provides new insight for the designing of microwave ignition. [Display omitted] [ABSTRACT FROM AUTHOR]

Au-modified CuFe2O4 nanotubes (Au-CuFe2O4 NTs) were synthesized through a combination of electrospinning and liquid precipitation methods, resulting in the uniform surface modification of well-dispersive Au nanoparticles (NPs) with an average diameter of 3.4 nm. Gas-sensing results demonstrated that the Au-CuFe2O4 sensors (0.5–5 wt % Au) exhibited significantly enhanced responses to xylene gas. Specifically, the 2 wt % Au-modified sensor displayed the highest response (38.1 @ 100 ppm xylene) and excellent selectivity at 260 °C. The comprehensive influences of ambient humidity and Au content on the detection capability of xylene using Au-CuFe2O4 NTs were discussed systematically. The superior activity of Au-modified sensors compared to pristine CuFe2O4 NTs was confirmed by their improved recovery characteristics in the presence of a high concentration of xylene. These enhanced sensing performances can be mainly attributed to electronic sensitization of Au and the synergistic catalytic effect of Au and CuFe2O4, indicating the great potential of Au-CuFe2O4 NTs for sensitive and selective xylene detection. [ABSTRACT FROM AUTHOR]

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Carbon-doped copper ferrite (C–CuFe2O4) was synthesized by a simple two-step hydrothermal method, which showed enhanced tetracycline hydrochloride (TCH) removal efficiency as compared to the pure CuFe2O4 in Fenton-like reaction. A removal efficiency of 94% was achieved with 0.2 g L−1 catalyst and 20 mmol L−1 H2O2 within 90 min. We demonstrated that 5% C–CuFe2O4 catalyst in the presence of H2O2 was significantly efficient for TCH degradation under the near-neutral pH (5–9) without buffer. Multiple techniques, including SEM, TEM, XRD, FTIR, Raman, XPS Mössbauer and so on, were conducted to investigate the structures, morphologies and electronic properties of as-prepared samples. The introduction of carbon can effectively accelerate electron transfer by cooperating with Cu and Fe to activate H2O2 to generate ·OH and ·O2−. Particularly, theoretical calculations display that the p, p, d orbital hybridization of C, O, Cu and Fe can form C–O–Cu and C–O–Fe bonds, and the electrons on carbon can transfer to metal Cu and Fe along the C–O–Fe and C–O–Cu channels, thus forming electron-rich reactive centers around Fe and Cu. This work provides lightful reference for the modification of spinel ferrites in Fenton-like application.

Using banana peel as raw material, the composite material CuFe2O4@BC was synthesised and used it to activate peracetic acid (PAA) to remove tetracycline (TC) in water. The crystal phase, morphology, and chemical bonding of the composite were analysed by XRD, SEM, FTIR, XPS, and other characterisation techniques. In the degradation experiments, CuFe2O4@BC showed high catalytic activity and found that the best dosage ratio of CuFe2O4@BC and PAA is 300 mg/L: 3 mmol/L, and under this condition, the removal rate of TC in 60 min reached 85%. CuFe2O4@BC showed degradation effect in a wide pH range, and the catalytic activity was found to be the best under acidic conditions. At the same time, after five cycles of test, the composite still maintained more than 80% of TC removal rate. The free radical quenching experiments proved that the main active species in the reaction were •OH, CH3COO• and CH3COOO•. [ABSTRACT FROM AUTHOR]

Carbon-doped copper ferrite (C-CuFe2O4) was synthesized by a simple two-step hydrothermal method, which showed enhanced tetracycline hydrochloride (TCH) removal efficiency as compared to the pure CuFe2O4 in Fenton-like reaction. A removal efficiency of 94% was achieved with 0.2 g L-1 catalyst and 20 mmol L-1 H2O2 within 90 min. We demonstrated that 5% C-CuFe2O4 catalyst in the presence of H2O2 was significantly efficient for TCH degradation under the near-neutral pH (5-9) without buffer. Multiple techniques, including SEM, TEM, XRD, FTIR, Raman, XPS M€ossbauer and so on, were conducted to investigate the structures, morphologies and electronic properties of as-prepared samples. The introduction of carbon can effectively accelerate electron transfer by cooperating with Cu and Fe to activate H2O2 to generate OH and .O2 -. Particularly, theoretical calculations display that the p, p, d orbital hybridization of C, O, Cu and Fe can form C-O-Cu and C-O-Fe bonds, and the electrons on carbon can transfer to metal Cu and Fe along the C-O-Fe and C-O-Cu channels, thus forming electron-rich reactive centers around Fe and Cu. This work provides lightful reference for the modification of spinel ferrites in Fenton-like application. [ABSTRACT FROM AUTHOR]

Magnetic CuFe2O4 was prepared with the modified sol–gel method and used for enhanced peroxymonosulfate (PMS) activation and ofloxacin (OFL) degradation. The OFL could almost degrade within 30 min at a catalyst dosage of 0.66 g/L, PMS concentration of 0.38 mM, and initial pH of 6.53 without adjustment, using response surface methodology (RSM) with Box-Behnken design (BBD). In the CuFe2O4/PMS system, the coexisting substances, including CO32−, NO3−, SO42−, Cl− and humic acid, have little effect on the OFL degradation. The system also performs well in actual water, such as tap water and surface water (Mei Lake), indicating the excellent anti-interference ability of the system. The cyclic transformation between Cu(II)/Cu(I) and Fe(III)/Fe(II) triggers the generation of active radicals including SO4•−, •OH, •O2− and 1O2. The OFL degradation pathway, mainly involving the dehydrogenation, deamination, hydroxylation, decarboxylation and carboxylation processes, was proposed using mass spectroscopy. Moreover, the toxicity assessment indicated that the end intermediates are environmentally friendly. This study is about how the CuFe2O4/PMS system performs well in PMS activation for refractory organic matter removal in wastewater.

Spinel ferrites have some benefits when used as supercapacitor electrode materials, most notably their outstanding long-term cycle stability and energy storage capacity. The materials we investigated were prepared and included Cu doping into Zn–Mg ferrites; these materials are designated as Zn 0.4 Mg 0.5 Cu 0.1 Fe 2 O 4 (ZCM1), Zn 0.3 Mg 0.5 Cu 0.2 Fe 2 O 4 (ZCM2), and Zn 0.2 Mg 0.5 Cu 0.3 Fe 2 O 4 (ZCM3). A variety of techniques, such as X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) analyses, electron paramagnetic resonance (EPR), and various electrochemical methods, were used to conduct a thorough analysis of their structural features, surface morphology, chemical composition, electrochemical activity, and capacitive performance. We used the solvothermal reflux synthesis method to dope the Zn–Mg ferrites with Cu to improve their performance. The ZCM3 electrode was the result of this change, and it showed a best specific capacitance (Cs) of 508.25 F/g at a current density (CD) of 1.75 A/g. Interestingly, this particular capacitance was higher than the other electrode materials such as ZCM1 and ZCM2 that we examined in this research. [ABSTRACT FROM AUTHOR]

The CuFe2O4/In2S3 composite was prepared by a simple mechanical grinding process and used for the photocatalytic degradation of tetracycline (TC) under visible light irradiation. The results showed that the photocatalytic degradation activity for tetracycline on the CuFe2O4/In2S3 composite photocatalyst with a mass ratio of 1:3 was 95.2%, which was higher than that of 12 and 63% on pure CuFe2O4 and In2S3 alone, as well as 89% on CuFe2O4/In2S3(1:1) and 79% on CuFe2O4/In2S3(3:1). Tetracycline photodegradation on CuFe2O4/In2S3 was a first-order reaction, and the rate constant of the tetracycline degradation reaction under visible light irradiation was 0.02162 min−1, which was 38 and 3.1 times higher than that of CuFe2O4 and In2S3 alone, respectively. This characterization results showed that CuFe2O4/In2S3(1:3) composites showed the high photodegradation efficiency and the highest photogenerated carrier separation efficiency. In addition, on the optimal reaction condition, an optimal photodegradation of 95.2% for tetracycline would achieved. The stable construction of the CuFe2O4/In2S3 heterojunction and the narrow band gap of CuFe2O4 or In2S3 enhance the light absorption capacity of the catalyst. The mechanism study shows that CuFe2O4 and In2S3 are excited by visible light to produce electrons, which transfer to the conduction band of CuFe2O4 and In2S3. Subsequently, the separation and transfer of photogenerated holes and photogenerated electrons are effectively improved by the Z-scheme photogenerated carrier transfer mechanism. The photogenerated electrons can reduce O2 to produce ·O2−, which together with h+ on the valence band becomes the main oxidation active species in the reaction system, and efficient oxidative degradation of tetracycline can be achieved. [ABSTRACT FROM AUTHOR]

Small and equally distributed Pd nanoparticles (NPs) are tightly anchored on the surface of magnetic and amino (–NH 2) functionalized CuFe 2 O 4 to obtain magnetically separable CuFe 2 O 4 –NH 2 @Pd catalyst with core-shell structure. Compared to the inherent catalytic activity of CuFe 2 O 4 , the catalytic performance of CuFe 2 O 4 –NH 2 @Pd for dehydrogenation of ammonia-borane (AB) and concurrent hydrogenation of different nitro aromatics by H 2 generated from AB methanolysis can be boosted more effectively than that of CuFe 2 O 4 @Pd, which is the control catalyst and is prepared by loading Pd NPs on pristine CuFe 2 O 4. As electron donating groups, the –NH 2 groups covalently bonded to the surface of CuFe 2 O 4 play vital roles in stabilizing Pd NPs, providing strong metal-support interaction and rendering enhanced catalytic activity. However, we find that the catalytic performance of CuFe 2 O 4 , CuFe 2 O 4 @Pd and CuFe 2 O 4 –NH 2 @Pd for the hydrogenation reduction of mercapto-substituted nitro aromatics (p -nitrothiophenol, p -NTP) is far inferior to that for the reduction of nitroarenes that do not contain a sulfur substituent. Therefore, it is quite essential to research and develop the new-type catalysts with more excellent catalytic performance. [Display omitted] • A facile three-step method has been developed to fabricate core-shell CuFe 2 O 4 –NH 2 @Pd. • CuFe 2 O 4 –NH 2 @Pd exhibits superior catalytic activity to CuFe 2 O 4 @Pd for hydrogenation of nitroaromatics. • –NH 2 grafted onto the surface of CuFe 2 O 4 plays vital role in enhancing catalytic activity. [ABSTRACT FROM AUTHOR]

Cuprospinel nanoparticles (CuFe2O4-NPs) were initially made in this study using the sol-gel process. Then, the effect of the main operational parameters, such as sulphate radical precursors (namely, peroxymonosulfate [PMS] and peroxydisulfate [PDS]), pH of aqueous solution, ultrasound (US) frequency and power, CuFe2O4 loading, reaction time, atenolol (ATL) concentration, as well as inorganic anions on the sonocatalytic process in removing ATL from water was investigated. The results revealed that the PMS outperformed the PDS due to its unsymmetrical structure. Under optimal conditions, the initial pH of the aqueous solution, the US frequency and power, the CuFe2O4 loading, the PMS concentration, and the ATL concentration were also obtained by 7.5, 80 kHz, 100 W, 0.4 g/L, 1.2 mM, and 0.5 mg/L, respectively. At the concentration of 10 mg/L of the ATL, its removal and the mineralisation rates were equal to 83.1% and 48.31%, respectively. The inhibitory effect of the inorganic anions on the removal of the ATL correspondingly followed the sequence of HCO3−>H2PO4−>SO42->NO3−. In the scavenging experiment, methanol showed greater effectiveness compared with other agents in the removal of the ATL, indicating that the SO4•- radicals were the dominant active species within the reaction. The reusability test also demonstrated that the CuFe2O4 efficiency decreased by almost 10% after five consecutive cycles. Besides, the intermediates of the ATL degradation were determined by the liquid chromatography-mass spectrometry (LC-MS) technique and the proposed mechanism for the ATL degradation was expressed. In general, the findings suggested that the US/PMS/CuFe2O4 process had a high synergistic index (SI) and could be effective in removing ATL from aqueous solutions. [ABSTRACT FROM AUTHOR]

The introduction of hexavalent chromium Cr(VI) through water sources can cause serious damage to humans and other organisms. Hence, the removal of toxic Cr(VI) ions from the water environment is of great importance in the field of wastewater treatment. In this study, the Cr(VI) removal was performed through the photoreduction technique. Because of its tunable optical band gap, tungsten oxide (WO3), which can be driven by the visible light, was selected as the photocatalyst. To enhance the effective separation of the photoinduced charge carriers, WO3 was coupled with a magnetic semiconductor, copper ferrite (CuFe2O4). A co-precipitation technique was used to synthesize WO3 in nanoparticle form and the as-prepared WO3 nanoparticles were used to prepare WO3/CuFe2O4 composites through an auto-combustion sol-gel technique. When WO3 was coupled with CuFe2O4, the Cr(VI) photoreduction efficiency was enhanced from 23.9% to 60.0% within 120 min of visible light irradiation. The Cr(VI) photoreduction performance of the WO3/CuFe2O4 composite was studied under various conditions also. Within this scope, the initial pH, ion concentration and photocatalyst concentration of the Cr(VI) solution was investigated. The effect of competing substances in a real wastewater sample on the Cr(VI) photoreduction activity was also studied. To understand the Cr(VI) photoreduction mechanism, electron-hole scavengers were used. Based on the trapping experiment, photoinduced electrons of both semiconductors contributed as the main active species in the Cr(VI) photoreduction process. According to reusability experiment, the Cr(VI) removal rate of the composite sample reduced from 60.0% to 47.2% after four consecutive photoreduction cycles. Highlights: Magnetic composite photocatalyst in nanoparticle size was obtained. Coupling WO3 with CuFe2O4 suppressed the recombination rate on WO3. Coupling WO3 with CuFe2O4 enhanced the Cr(VI) removal rate of WO3 by almost 36%. Competing substances in the real wastewater environment suppressed the Cr(VI) photoreduction efficiency by almost 9%. The photoinduced electrons were the main active species in the Cr(VI) photoreduction process. [ABSTRACT FROM AUTHOR]

In contemporary times, there has been a notable emphasis on the advancement of adsorbents with high efficiency for the purpose of extracting organic dyes from wastewater. Therefore, a suggested method involves improving the surfaces of adsorbents by changing polymers in order to make them better at absorbing substances. The goal of this study was to create a very effective nanocomposite (NCs) by combining CuFe2O4 nanoparticles (CuF NPs) and zeolite (ZSM-5) with different types of cellulose, such as cellulose (CE), cellulose acetate (CEA), and carboxymethyl cellulose (CMC), in order to remove Brilliant Green (B.G.), a cationic dye, from water solutions. We investigated the influence of several factors on the efficacy of dye removal by NCs. These factors included the kind of cellulose derivative used, adsorbent dose, solution temperature, pH, and contact duration. The results of the prepared ternary ZSM-5/CuF/CE, ZSM-5/CuF/CEA, and ZSM-5/CuF/CMC NCs show that among the fabricated NCs, the ZSM-5/CuF/CE NCs have the highest adsorption capacity (9.66 mg/g). This result highlights the promising capability of these NCs in effectively removing B.G. dye. The results obtained from the studies on dye removal provided evidence that the adsorption process occurred spontaneously and exothermic, as supported by both thermodynamic and kinetic criteria. The values of the R2 correlation coefficient for ternary ZSM-5/CuF/CE and ZSM-5/CuF/CEA NCs for B.G. dye were 0.993 and 0.995, respectively.

This work describes the hydrogen production from sodium borohydride (NaBH 4) hydrolysis over the homogenous copper ferrite (CuFe 2 O 4) nanocubes which were produced by one-pot approach without using any surfactant. The CuFe 2 O 4 nanocubes have a dimension of about 100 nm in size. X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) were used to characterize the morphology, structure, and phase of the sample. The magnetic CuFe 2 O 4 nanocubes were utilized in the hydrolysis of NaBH 4 to produce hydrogen, and demonstrated good catalytic activity and recyclability. The rate of hydrogen production of 10 wt% NaBH 4 hydrolysis reached up to 1.5 L/min/g at 303 K over CuFe 2 O 4 nanocubes, which is substantially greater than in other shaped CuFe 2 O 4 materials. In the hydrogen generation process, the effects of NaOH concentration, NaBH 4 concentration, and reaction temperature were also investigated. Magnetic CuFe 2 O 4 nanocubes show a comparatively low activation energy of 41.53 kJ/mol, according to the kinetic analyses. Hence, the uniform CuFe 2 O 4 nanocubes have much potential in hydrolysis for hydrogen generation. [ABSTRACT FROM AUTHOR]

The aim of this study was to fabricate CNT@MgO@CuFe2O4 nanorod composite as a novel adsorbent for the removal of Pb (II) ions from aqueous media. The structural features of CNT, CNT@MgO and CNT@MgO@CuFe2O4 composite were studied by FTIR, XRD, VSM, BET, SEM, EDX, and Map analyses. BET analysis indicated that MgO/CNT and CNT@MgO@CuFe2O4 composite have mesoporous structures. Also, the specific surface area of CNT@MgO and CNT@MgO@CuFe2O4 were 84.84 and 95.79 m2/g, respectively. VSM analysis also indicated that the CNT@MgO@CuFe2O4 composite has a paramagnetic property. Moreover, the utmost sorption efficiency of Pb (II) ions using CNT, CNT@MgO and CNT@MgO@CuFe2O4 composite were obtained 92.37%, 96.34%, and 99.09%, respectively, indicating that the removal efficiencies were significantly increased by modifying the CNT surface. Besides, the maximum sorption capacity of CNT, CNT@MgO and CNT@MgO@CuFe2O4 by the Langmuir model were 27.7, 32.68, and 47.62 mg/g, respectively, indicating that the CNT@MgO@CuFe2O4 composite has the highest sorption capacity. Also, the equilibrium and thermodynamic behavior indicated that the sorption process of Pb (II) using all three adsorbents is physical, favorable, exothermic, and spontaneous. In general, the findings revealed that the CNT@MgO@CuFe2O4 nanorod composite can be used effectively to remove Pb (II) ions from wastewater. [ABSTRACT FROM AUTHOR]

[Display omitted] • The p-n heterojunction photoanode γ-Fe 2 O 3 /CuO is obtained. • The built-in electric filed and band bending between CuO and γ-Fe 2 O 3 are formed. • Carrier separation and transfer are boosted. • The existence of CuFe 2 O 4 helps improve the photo-corrosion resistance. • The enhanced oxygen vacancies accelerate the water oxidation. Fe 2 O 3 is a promising n -type semiconductor as the photoanode of photoelectrochemical water-splitting method due to its abundance, low cost, environment-friendly, and high chemical stability. However, the recombination of photogenerated holes and electrons leads to low solar-to-hydrogen efficiency. In this work, to overcome the recombination issue, a p-type semiconductor, CuO, is introduced underneath the γ-Fe 2 O 3 to synthesize γ-Fe 2 O 3 /CuO on the FTO substrate. Along with the formation of p-n heterojunction, CuFe 2 O 4 is in situ generated at the interface of γ-Fe 2 O 3 and CuO. The existence of Cu 2 O in CuO and CuFe 2 O 4 promotes the charge transfer from CuO to γ-Fe 2 O 3 and within CuFe 2 O 4 , respectively, resulting in creating an internal electric field in γ-Fe 2 O 3 /CuO and leading to the conduction band of CuO bending up and γ-Fe 2 O 3 bending down. Additionally, Cu(II) in CuFe 2 O 4 contributes to fast electron capture. Consequently, the charge transfer efficiency and charge separation efficiency of photo-generated holes are promoted. Hence, γ-Fe 2 O 3 /CuO exhibits an enhanced photocurrent density of 13.40 mA cm−2 (1.9 times higher than γ-Fe 2 O 3). The photo corrosion resistance of CuO is dramatically increased with the protection of CuFe 2 O 4 , resulting in superior high chemical stability, i.e. 85% of the initial activity remains after a long-term test. [ABSTRACT FROM AUTHOR]

The present paper reports the synthesis of magnetic photo-Fenton catalysts based on CuFe2O4 via an environmentally friendly sol-gel method at different annealing temperatures (700, 800, and 900°C) using tamarind fruit extract as a chelating agent. The catalysts were characterized by X-ray diffraction, scanning electron microscopy, nitrogen adsorption, Fourier-transform infrared spectroscopy, and vibrating sample magnetometry. Their photo-Fenton catalytic performance was tested with oxalic acid for the degradation of Methylene Blue under UVA light and under visible light. According to the results, the annealing temperature was found to be the important factor, significantly affecting the oxalic acid-induced-photo-Fenton activity. When the annealing temperature increased from 700 to 800°C, the catalytic performance was strongly improved, which can be explained by the enhanced Fe3+ content on the catalyst surface. At higher annealing temperature, due to the growth and agglomeration of particles, the specific surface area was decreased, consequently reducing the catalytic activity. The sample prepared at 800°C also displayed good ferromagnetic properties, making it the most promising recyclable material for wastewater treatment in this study. [ABSTRACT FROM AUTHOR]

Magnetic CuFe2O4 powder obtained by sol−gel method and coupled photocatalysis was used to activate peroxydisulfate for tetracycline (TC) removal. A scanning electron microscope, X−ray diffraction Raman spectroscopy and FT−TR were used to characterize the catalysts. The degradation efficiency and stability of TC were highest under neutral conditions. The TC degradation rate reached 91.1% within 90 min. The removal rate of total organic carbon reaches 39.6% under optimal conditions. The unique electron transfer property of CuFe2O4 was utilized to achieve the synergistic effect of photocatalysis and persulfate oxidation. The main oxidizing substances involved in the decomposition were sulfate radicals and hydroxyl radicals, and the removal rate of over 84% could be maintained after five cycles of experiments. [ABSTRACT FROM AUTHOR]

This study aims to develop a self-combustion method for use in the preparation of copper and cobalt ferrites. This development was based on the full use of dry leaves of Corchorus olitorius plant in order to stimulate the preparation of the studied ferrites by making full use of the small amount of carbon produced from the combustion process. The fabrication of CuFe2O4 and CoFe2O4 with spinel-type structures and the Fd3m space group is confirmed by XRD and FTIR investigations. Two major vibration bands occur laterally at 400 cm−1 and 600 cm−1. We were able to understand the existence of two stages through the thermal behavior based on TG-DTG analysis for the materials under investigation. The first is from room temperature to 600 °C, which indicates the formation of reacting oxides with Co or Cu ferrites, while the second is from 600–1000 °C, which indicates the growth in the ferrite fabrication. The surface morphological analyses (SEM/EDS and TEM) display formation of homogeneous and nanosized particles. The surface properties of the samples containing CoFe2O4 are superior compared to those of the samples not containing CuFe2O4. Every sample under investigation displays type-IV-based isotherms with a type-H3 hysteresis loop. The VSM approach was used to evaluate the magnetic characteristics of Cu and Co ferrites. Copper ferrites have a magnetization of 15.77 emu/g, and cobalt ferrites have a magnetization of 19.14 emu/g. Moreover, the squareness (0.263) and coercivity (716.15 G) of cobalt ferrite are higher than those of copper ferrite. [ABSTRACT FROM AUTHOR]

Using iron nitrate and copper nitrate as raw materials, mesoporous material SBA-15 as template agent and n-hexane as solvent, CuFe2O4 samples of mesoporous loaded composite metal oxide catalysts were successfully prepared by calcination at 600 °C. The samples were characterized by X-ray diffraction (XRD), thermogravimetric-differential scanning analysis (TG-DSC), and scanning electron microscopy (SEM). The selective oxidation of benzyl alcohol by CuFe2O4 under different catalytic conditions was investigated using benzyl alcohol as a model compound, and the oxidation products were analyzed by high performance liquid chromatography (HPLC). The results showed that the CuFe2O4 catalyst prepared by calcination at 600°Cwas the best. The best selective oxidation conditions were achieved at a reaction system temperature of 90 °C, a catalyst dosage of 4 g/L, a molar ratio 1:1 of H2O2 dosage to benzyl alcohol, and a reaction time of 4 h. The conversion of benzyl alcohol under this condition was 66.95%, and the selective conversion of benzaldehyde was 96.07%. This indicates that CuFe2O4 is a composite metal oxide with high selective oxidation of benzyl alcohol and has wide application prospects. [ABSTRACT FROM AUTHOR]

The primary purpose of this study was to produce an ore-based high-capacity supercapacitor electrode. For this, chalcopyrite ore was first leached with nitric acid, and then metal oxide synthesis was carried out immediately on nickel foam using a hydrothermal technique from the solution. Cauliflower-patterned CuFe2O4 with a wall thickness of about 23 nm was synthesized on the Ni foam surface, characterized by XRD, FTIR, XPS, SEM, and TEM investigations. The produced electrode also displayed a feature of a battery-like charge storage mechanism with a specific capacity of 525 mF cm−2 at 2 mA cm−2 current density, energy of 8.9 mWh cm−2, and a power density of 233 mW cm−2. Additionally, even after 1350 cycles, this electrode still performed at 109% of its original capacity. The performance of this finding is 255% higher than that of the CuFe2O4 in our earlier investigation; despite being pure, it performs far better than some of its equivalents in the literature. Obtaining such performance from an electrode made from ore indicates that the use of ore has a lot of potential for supercapacitor production and property improvement. [ABSTRACT FROM AUTHOR]

We have developed a facile three-step fabricating procedure whereby uniformly distributed and highly catalytically active Pt nanoparticles (NPs) were anchored on the superparamagnetic and catalytically active CuFe2O4 submicrospheres to form core-shell CuFe2O4@Pt nanocomposite catalyst. The as-prepared CuFe2O4 and CuFe2O4@Pt catalysts were characterized by transmission electron microscopy (TEM) and high-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Their catalytic properties for reduction of [Fe(CN)6]3− to [Fe(CN)6]4− by S2O32− were comparatively studied. The results indicate that the inherent catalytic performance of CuFe2O4 can be improved dramatically when Pt NPs are homogeneously dispersed and firmly immobilized on its surface. The remarkably enhanced catalytic activity is mainly ascribed to the excellent catalytic performance of noble metal Pt. Highlights: A facile three-step fabricating procedure is demonstrated to fabricate CuFe2O4@Pt NPs. CuFe2O4@Pt exhibits superior catalytic efficiency to CuFe2O4 for reduction of [Fe(CN)6]3−. The enhanced mechanism is due to the excellent catalytic activity of noble metal Pt. [ABSTRACT FROM AUTHOR]

This study reported a new application of CuFe2O4 spinel as an efficient heterogeneous catalyst for the selective oxidation of isoeugenol to licarin A under mild conditions. The CuFe2O4 was prepared via a simple method and characterized by various modern techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX), and high-resolution transmission electron microscopy (HR-TEM). The XRD and HR-TEM results confirmed the structure and morphology of spinel materials, while the SEM–EDX provided valuable information on the material component. CuFe2O4 catalyst showed excellent catalytic activity in the selective oxidation of isoeugenol to give a high yield of licarin A under mild conditions. In addition, the catalyst was stable and able to reuse at least four times without the loss of catalytic activity. [ABSTRACT FROM AUTHOR]

S-scheme-based hydrothermal synthesis of SiO2@CuFe2O4-AgI composites was effectively described in this work. The photo-degradation of hazardous dyes like methylene blue (MB) and methyl orange (MO) was utilized to test nanocomposites with variable weight percent of AgI for photocatalytic activity in the visible range. In terms of photocatalytic activity, SiO2@CuFe2O4-AgI with a 15% AgI loading beat both pure and hybrid composites. In terms of MO degradation, the hybrid composite with 15% AgI loading degrades 16 times and 8 times faster than pristine CuFe2O4 and AgI samples, respectively, while in terms of MB degradation, it degrades 18.67 times faster and 9.33 times faster than pristine samples. The increased surface area decreased the recombination rate of photogenerated e− -h+ pairs, quicker separation of photogenerated carriers, and high redox capacity of SiO2@CuFe2O4-AgI (15%) all contribute to improved photocatalytic performance. The hybrid composite is chemically stable and reusable even after 10 cycles. Because of the coordinated Fermi level between CuFe2O4 and AgI, SiO2 acts as a transfer bridge for electrons in a layered structure. Furthermore, the scavenger experiment demonstrates that •O2-, •OH, and h+ are significant reactive species that efficiently aided the photodegradation of dyes. Current research proposes a novel and cost-efficient method for creating a stable semiconductor-based photocatalytic system and a viable strategy for future applications.

Copper ferrite (CuFe2O4) possesses an indirect bandgap in the range of 1.54-1.95 eV. It is used as an attractive p-type photocathode in photoelectrochemical (PEC) water splitting, and theoretically it can yield a maximum photocurrent density of ∼27 mA/cm2 and a maximum solar-to-hydrogen conversion efficiency of ∼33%. To date, only a few reports have been published on CuFe2O4 photocathodes with very low-photocurrent densities, with a maximum value of 0.4 mA/cm2 at 0.4 V vs RHE. Herein, we prepared a CuFe2O4 photocathode on FTO glass with the sol-gel method followed by either high-temperature flame annealing or furnace annealing. We found that the flame-annealed CuFe2O4 photocathode generated a photocurrent density of 1.82 mA/cm2 at 0.4 V vs RHE that is approximately 3.5 times higher than the furnace-annealed CuFe2O4 (0.52 mA/cm2). This photocurrent density is also higher than those of all the reported CuFe2O4 photocathodes, and any Cu containing ternary oxide (Cu-M-O, M: Fe, Bi, V, and Nb) photocathode (0.1-1.3 mA/cm2 at 0.4 V vs RHE). An improved PEC performance of the flame-annealed CuFe2O4 photocathode is elicited owing to the beneficial effects of flame annealing on the physical, optical, and electrical properties of CuFe2O4. Flame annealing enhances the light absorption property of the CuFe2O4 photocathode by slightly reducing the bandgap, and by forming a thicker film with increased porosity. Flame annealing also reduces the oxygen vacancy concentration in CuFe2O4, thus facilitating charge transport and interfacial charge transfer processes. Moreover, flame annealing requires only 16 min, which is much shorter than the time required for furnace annealing (∼9 h). These results demonstrate that flame annealing is a rapid and effective means for fabricating metal oxide photoelectrodes with an enhanced PEC water splitting performance.

Multifunctional nanoplatforms based on novel bimetallic nanoparticles have emerged as effective radiosensitizers owing to their potential capability in cancer cells radiosensitization. Implementation of chemotherapy along with radiotherapy, known as synchronous chemoradiotherapy, can augment the treatment efficacy. Herein, a tumor targeted nanoradiosensitizer with synchronous chemoradiotion properties, termed as CuFe 2 O 4 @BSA-FA-CUR, loaded with curcumin (CUR) and modified by bovine serum albumin (BSA) and folic acid (FA) was developed to enhance tumor accumulation and promote the anti-cancer activity while attenuating adverse effects. Both copper (Cu) and iron (Fe) were utilized in the construction of these submicron scale entities, therefore strong radiosensitization effect is anticipated by implementation of these two metals. The structure–function relationships between constituents of nanomaterials and their function led to the development of nanoscale materials with great radiosensitizing capacity and biosafety. BSA was used to anchor Fe and Cu ions but also to improve colloidal stability, blood circulation time, biocompatibility, and further functionalization. Moreover, to specifically target tumor sites and enhance cellular uptake, FA was conjugated onto the surface of hybrid bimetallic nanoparticles. Finally, CUR as a natural chemotherapeutic agent was encapsulated into the developed bimetallic nanoparticles. With incorporation of all abovementioned stages into one multifunctional nanoplatform, CuFe 2 O 4 @BSA-FA-CUR is produced for synergistic chemoradiotherapy with positive outcomes. In vitro investigation revealed that these nanoplatforms bear excellent biosafety, great tumor cell killing ability and radiosensitizing capacity. In addition, high cancer-suppression efficiency was observed through in vivo studies. It is worth mentioning that co-use of CuFe 2 O 4 @BSA-FA-CUR nanoplatforms and X-ray radiation led to complete tumor ablation in almost all of the treated mice. No mortality or radiation-induced normal tissue toxicity were observed following administration of CuFe 2 O 4 @BSA-FA-CUR nanoparticles which highlights the biosafety of these submicron scale entities. These results offer powerful evidence for the potential capability of CuFe 2 O 4 @BSA-FA-CUR in radiosensitization of malignant tumors and opens up a new avenue of research in this area. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, CuFe2O4 ferrite was supported on biochar produced from malt biomass residues as a photocatalyst for degradation of methylene blue (MB), methyl orange (MO), and tartrazine (TZ) dyes. XRD, FT-IR, and FE-SEM were used to characterize the crystallinity and morphology of the samples. The characterization showed that the ferrite was uniformly supported on the surface of the biochar, confirming the formation of the composite. Degradation tests showed that CuFe2O4 degraded approximately 50, 47, and 62% of MB, MO, and TZ dyes, respectively, after 60 min of reaction. On the other hand, the CuFe2O4/biochar composite showed a significant increase in dye degradation, ~ 100%, for all three dyes. This increase in degradation efficiency may be due to less agglomeration of supported particles and due to decreased recombination of electron/hole pairs. Thus, results showed that the photocatalyst composite produced in this study is an effective alternative for removing dyes from wastewater. [ABSTRACT FROM AUTHOR]

The inert component is an important part of the oxygen carrier in the chemical looping gasification. In this study, a variety of characterization analyses were conducted to investigate a role of SiO2 in crystal structure, morphology, pore structure during multiple cycles of CuFe2O4/SiO2 oxygen carrier. It was shown that CuFe2O4 presented an excellent cycle stability. During cycles, the inert component SiO2 always keeps the same phase, and the active component CuFe2O4 is the continuous loss and gain of lattice oxygen. There are not change much in elemental composition of CuFe2O4 during multiple cycles. Inert component SiO2 inhibiting the loss of copper during multiple cycles that obtained from the SEM analyses. Combined with the Zener effect, it is found that the inert component SiO2 as second-phase particles in the boundary between the CuFe2O4 grains to be inhibited the growth of the CuFe2O4 grains, which would be maintain the integrity of the oxygen carrier microwave structure. This can be strengthen cycle stability in the chemical looping gasification. Therefore, SiO2 with zener pinning effect would be well the cycle stability of the oxygen carrier.

Peroxymonosulfate (PMS), which is dominated by free radical (SO 4 •-) pathway, has a good removal effect on organic pollutants in complex water matrices. In this article, a new catalyst (CFM@NC) was synthesized by hydrothermal carbonization method with chitosan (CS) as N and C precursors, and used to activate PMS to degrade dye wastewater. CFM@NC/PMS system can degrade 50 mg·L−1 rhodamine B by 99.59 % within 30 min, and the degradation rate remains as high as 97.32 % after 5 cycles. It has good complex background matrices, acid-base anti-interference ability (pH 2.6–10.1), universality and reusability. It can degrade methyl orange and methylene blue by >98 % within 30 min. The high efficiency of the composite is due to the fact that CS-modified MoS 2 as a carrier exposes a large number of active sites, which not only disperses CuFe 2 O 4 nanoparticles and improves the stability of the catalyst, but also provides abundant electron rich groups, which promotes the activation of PMS and the production of reactive oxygen species (ROS). PMS is effectively activated by catalytic sites (Cu+/Cu2+, Fe2+/Fe3+, Mo4+/Mo6+, pyridine N, pyrrole N, edge sulfur and hydroxyl group) to produce a large number of radicals to attack RhB molecules, causing chromophore cleavage, ring opening, and mineralization. Among them, free radical SO 4 •- is the main ROS for RhB degradation. This work is expected to provide a new idea for the design and synthesis of environmentally friendly and efficient heterogeneous catalysts. • Highly dispersed CuFe 2 O 4 nanoparticles can effectively inhibit particle aggregation. • Chitosan derived N-doped carbon can effectively activate peroxymonosulfate in cooperation with MoS 2. • Rich functional groups in chitosan can react with metal to form complexes and inhibit metal leaching. • SO 4 •- is the main active species in the degradation process. • CFM@NC/PMS system has a wide pH range (2.6–10.1) and strong ion anti-interference ability. [ABSTRACT FROM AUTHOR]

Bacterial infection has become the second leading cause of death in the world. Exploring a new highly antibacterial catalyst to replace traditional antibacterial agent is crucial for the society development of human beings. In this study, CuFe 2 O 4 /Lg-based carbon composited catalysts were rationally constructed by facile hydrothermal method. Lignin-derived carbon with enormous oxygen-containing functional group was beneficial to anchor CuFe 2 O 4 nanoparticles. The close contact interface between CuFe 2 O 4 and Lignin-based carbon material was expected to extend the range of optical absorption and promote the separation and transportation of photogenerated carriers. Under NIR (980 nm, 1.5 W/cm2) light irradiation, the as-prepared CuFe 2 O 4 /Lg (20 μg/mL) exhibited excellent photo/photothermal synergetic in vitro (against Escherichia coli and Staphylococcus aureus) and in vivo (against Staphylococcus aureus -infected mouse wound model) antibacterial performance. Furthermore, the cell count assay kit 8 (CCK-8 kit) demonstrated the good biocompatibility of this material. On the basis of the experimental results, a possible antibacterial mechanism based on the synergetic photothermal and photodynamic therapies was proposed. This work presented a lignin- derived carbon-based highly efficient antibacterial disinfection agent with desirable biosafety. • CuFe 2 O 4 /Lignin-based carbon composite was obtained by facile hydrothermal method. • CuFe 2 O 4 /Lg exhibited excellent synergetic antibacterial performance. • Detailed antibacterial mechanism based on synergetic effects was investigated. [ABSTRACT FROM AUTHOR]

Six kinds of CuFe 2 O 4 , including capsule-shaped CuFe 2 O 4 -C, plate-shaped CuFe 2 O 4 -P, polyhedral-shaped CuFe 2 O 4 -O, and irregular shaped catalysts prepared by co-precipitation (CuFe 2 O 4 -CO), by microwave heating (CuFe 2 O 4 -MW), and by hydrothermal synthesis (CuFe 2 O 4 -S), were used in the microwave-assisted catalytic wet peroxide oxidation (MW-CWPO) process to remove phenol from wastewater. The physicochemical properties of the catalysts were dependent on preparation methods. The catalytic activities were in the order of CuFe 2 O 4 -CO (95.3 %) >> CuFe 2 O 4 -P (78.8 %) > CuFe 2 O 4 -C (72.7 %) > CuFe 2 O 4 -MW (67.1 %) > CuFe 2 O 4 -S (63.3 %) > CuFe 2 O 4 -O (60.0 %). Effects of CuFe 2 O 4 -CO dosage, H 2 O 2 , pH, phenol initial concentration, anions, and MW in the MW-CWPO process were then systematically studied. Under optimal conditions of pH = 3, H 2 O 2 = 1 mL/L, and CuFe 2 O 4 -CO = 0.5 g/L, MW energy of 99 kJ (550 W, 3 min) and 132 kJ (550 W, 4 min) were found essential to achieve 99.6 % removal rate of phenol and 95.3 % removal rate of chemical oxygen demand (COD). Possible degradation pathways were suggested: phenol was firstly oxidized into hydroquinone and catechol, which further degraded into p -benzoquinone, 1,2 -benzoquinone, respectively. Finally, these compounds transformed into oxalic acid, CO 2 , and H 2 O within 4 min. The proposed mechanism suggested that the catalyst CuFe 2 O 4 -CO generates more "hot spots" due to its irregular shape, which enhances MW scattering and absorbing abilities. Consequently, the chemical composition and crystal structure of the catalyst significantly promote the decomposition of H 2 O 2 to generate free radicals. The CuFe 2 O 4 -CO has an opportunity of potential engineering application due to its high efficiency and stability. [Display omitted] • Six kinds of CuFe 2 O 4 are prepared and CuFe 2 O 4 -CO exhibits the highest catalytic activity for phenol degradation. • Catalyst with an irregular or surface fluff capsule shape exhibit excellent abilities of scattering and absorbing MW. • A synergistic effect of catalyst, MW, and H 2 O 2 contributes to the high degradation efficiency of phenol. • MW combined with catalyst enhance the H 2 O 2 utilization efficiency to generate more free radicals. [ABSTRACT FROM AUTHOR]

Oxygen vacancies are widely employed to augment the catalytic reactivity in the selective catalytic reduction of NO by CO (CO-SCR) process. Herein, the specific promotion mechanism of oxygen vacancies was intensively explored through a series of CuFe 2 O 4 catalysts via experiments and density functional theory (DFT) simulations. After the modification of oxygen vacancies, NO conversion was enhanced by 20 %-32 % and N 2 selectivity was improved. Characterizations revealed that the redox performance, NO adsorption and activation capacity, active centers, and acidic sites of CuFe 2 O 4 can be improved by enriched oxygen vacancies, contributing to the superior CO-SCR performance. DFT results identified that the adsorption energies of reactants were elevated and the intermediate reaction energy barriers were decreased with more oxygen vacancies. Furthermore, the CO-SCR reaction pathways with CuFe 2 O 4 catalyst were proposed according to in-situ test results: it follows the Langmuir-Hinshelwood (LH) and Eley-Rideal (ER) mechanisms in the low-temperature range (50–250 ℃) and the Marse-van-Krevelen (Mvk) mechanism in the high-temperature range (≥250 ℃). Overall, this work highlights the bright prospects of oxygen vacancies on the modification of CO-SCR catalysts. • Oxygen vacancies promote the CuFe 2 O 4 catalysts to achieve 20 %-32 % NO conversion enhancement and improved N 2 selectivity. • Oxygen vacancies improve the reducibility, acidic sites, active centres, and NO activation and adsorption capacity of CuFe 2 O 4. • Oxygen vacancies reduce the energy barriers of CO-SCR intermediate reactions. • The CO-SCR reaction over CuFe 2 O 4 follows the combination of LH and ER mechanisms at 50–250 ℃ and Mvk mechanism above 250 ℃. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sulfonated crosslinked PVA-CuFe 2 O 4 magnetic nanocomposite prepared. • PVA-CuFe 2 O 4 used as a catalyst for amino naphthoquinones and imidazole derivatives preparation. • The catalyst showed excellent reusability and magnetic separation. • Imidazole derivatives showed growth-inhibiting antibacterial and antioxidant activities. • Imidazole derivatives showed high anti-breast cancer activity against MCF-7 cell lines. In this study, a crosslinked poly(vinyl alcohol) (CPVA) was synthesized using glutaraldehyde as the cross-linking agent. Subsequently, the CPVA was sulfonated with chlorosulfonic acid to yield SCPVA. The SCPVA was then used in the in situ coprecipitation method to create a magnetic nanocomposite named SCPVA@CuFe 2 O 4. Characterization of the SCPVA@CuFe 2 O 4 nanocatalyst was conducted through EDX, XRD, TGA, FTIR, VSM, and SEM analyses. The catalytic activity of SCPVA@CuFe 2 O 4 was evaluated through studies on synthesizing imidazoles and amino naphthoquinones. Using 0.08 g of the catalyst, yields of amino naphthoquinones and imidazoles reached 88–94 % and 89–95 %, respectively. The synthesized derivatives showed high antioxidant and antibacterial activity close to the DPPH solution and tested bacteria, correspondingly. The synthesized derivatives exhibited high toxicity against breast cancer cell lines and demonstrated promising antioxidant and antibacterial activities. [ABSTRACT FROM AUTHOR]

Magnetic CuFe2O4 nanoparticles were successfully synthesized with a coprecipitation method at 500 °C calcination temperature, and were utilized to degrade levofloxacin (LEV) as a peroxymonosulfate (PMS) activator. The structure and composition of the nanocatalyst were characterized by a series of methods, including scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometer and thermogravimetric analysis. The effects of the PMS concentration, the catalyst dosage, the LEV initial concentration, the pH value and the inorganic anions on the LEV degradation were also explored. The results revealed that the designed CuFe2O4/PMS system had high activity and excellent stability in the complex conditions. The degradation efficiency of LEV still reached above 80% after four recycles of CuFe2O4 catalyst. The reactive species quenching experiments and electron paramagnetic resonance analysis suggested the existence of superoxide radicals, single oxygen, hydroxy radicals and sulfate radicals, and the first two were dominant radical oxygen species. Based on the mechanism analyses, the efficient degradation of LEV was probably due to the continuous generation of reactive species under the condition of Fe(III)/Fe(II) and Cu(II)/Cu(I) redox cycles. The research provided a reasonable reference for the PMS activation mechanism-based spinel-type ferrite catalysis. HIGHLIGHTS The synthesized CuFe2O4 nanoparticle exhibited excellent structural characteristics.; The influencing factors for LEV degradation in CuFe2O4/PMS system were explored.; The CuFe2O4 catalyst exhibited outstanding reusability, stability and easier separation.; The mechanism of PMS activation based on catalysis of CuFe2O4 was further explored.;

CuFe2O4 ferrite was synthesized by citrate precursor and then calcined at 800, 900, and 1000 °C. Structural properties showed that the X-ray diffraction patterns of the samples could be easily indexed to tetragonal CuFe2O4 ferrite with the spatial group the I 41/AMD. As the calcination temperature increased, the larger Cu2+ ion at the tetragonal site substituted the smaller Fe3+ ion at the octahedral site. The half-width of X-ray diffraction peaks can be affected by several factors such as instrumentation, crystallite size, and lattice microstrain broadening. The results of crystallite size and Microstrain estimated by different methods for the samples show that the Size-strain Plot method is more accurate, the value of R2 is close to 1 and all data points touch the fitting line better than other methods. The results showed that the increase in crystal size with calcination temperature could be mainly attributed to the increase of stretching microstrain.

The development of cheap and efficient catalysts for persulfate activation in advanced oxidation processes based on persulfate is important and promising in the wastewater treatment field. Herein, conductive carbon black loaded CuFe2O4 (CCB-CuFe2O4) had been prepared via a sol-gel method and was used as a catalyst to activate persulfate for the removal of phenol in water. The CCB-CuFe2O4 was characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, Brunauer--Emmett--Teller, and Raman spectroscopy, which confirmed that CuFe2O4 nucleated on the defect of CCB. The performance of the activation on persulfate was studied by determining the concentration of phenol and chemical oxygen demand of the water. The activity of the catalyst is the highest when the content of CuFe2O4 in the catalyst is 10%. The removal rate of 100 mg/L phenol reached 100% in 30 min under the optimized operation condition, which was 2.0 g/L CCB-CuFe2O4, 2.0 mmol/L persulfate (PS) and pH = 11. The factors of effect on the catalysis performance were discussed. CCB-CuFe2O4 can be used in the pH range of 3~11 and the presence of HCO-3 can promote phenol degradation rate. The use of CCB-CuFe2O4 catalyst obviously reduced the dose of PS in the process of phenol oxidation degradation. Furtherly, quenching experiments verified that the most important reactive species in the CCB-CuFe2O4/PS/phenol system is singlet oxygen (¹O2). [ABSTRACT FROM AUTHOR]

The presence of sulfur components in diesel fuel can produce SO x gases, which emit from the combustion of diesel fuel and cause serious environmental problems. In this study, four various adsorbents biochar/CuFe 2 O 4 (BC/CuFe 2 O 4) , oxidized biochar / CuFe 2 O 4 (O-BC/CuFe 2 O 4), ethylene diamine-functionalized biochar/CuFe 2 O 4 (Et-BC/CuFe 2 O 4) and melamine-functionalized biochar/CuFe 2 O 4 (Me-BC/CuFe 2 O 4) were prepared for application in the total sulfur (all sulfur compounds) adsorption from diesel fuel. The prepared samples were characterized by XRD, TGA, VSM, FT-IR, FE-SEM, TEM and Raman techniques. Also, the Response Surface Methodology-Box-Behnken design was used in order to optimize adsorption key parameters included contact time, amount of adsorbent and percentage of Cu. Because of the presence of CuFe 2 O 4 nanoparticles, all of the prepared adsorbents can be regenerated and reused for consecutive adsorption tests. The π-complexation can be formed between Cu in adsorbents and aromatic sulfur compounds. Also Cu+2 can be a proper cation for adsorption of mercaptan components from diesel fuel. Formation of oxygenated group in O-BC sample and presence of –NH 2 functions in Et-BC and Me-BC samples can form hydrogen bonding with sulfur atom in sulfur compounds and create a very high adsorption capacity. Kinetic as well as isotherm studies showed that total sulfur adsorption by the prepared adsorbents followed second order and Langmuir adsorption model. For the sample of Me-BC/CuFe 2 O 4 , the adsorption capacity was obtained 1666.7 mg/g, while this value was 192.3 mg/g in the presence of BC adsorbent. It was found that 98.6% of total sulfur was removed by Me-BC/CuFe 2 O 4. Thermodynamic data demonstrated that total sulfur adsorption was spontaneous and followed an endothermic path. Regeneration of the prepared adsorbents employing NaOH solution showed that the adsorbents have suitable reusabilities after five sorption and desorption runs. • Economical biochar-based adsorbents were successfully synthesized. • The adsorbents were used in the total sulfur adsorption from diesel fuel. • Large adsorption capacity (1666.7 mg/g) was observed for total sulfur adsorption in the presence of Me-BC/CuFe2O4 sample. • The adsorbents can be easily reused several times. [ABSTRACT FROM AUTHOR]

The aim of this study was to synthesize CuFe 2 O 4 together with g-C 3 N 4 and GNPs in various combinations on the surface of Ni foam for use as anode materials in supercapacitors. The fabricated electrodes were investigated by XRD, FTIR, XPS, BET, SEM and TEM for content and by CV, GCD and EIS analysis for electrochemistry. The characterization results showed that CuFe 2 O 4 was successfully synthesized together with g-C 3 N 4 and GNPs in a nanosponge-like geometry. The highest value of specific capacitance was found to be 989 mF/cm2 at 2 mA measurement in the triple combination. Moreover, the stability of this electrode was measured to be 70% after 1500 cycles at 16 mA, while the energy and power densities were calculated to be 27.8 mWh/cm2 and 300 mW/cm2, respectively. The EIS results show that the carbon-based component increased the Cs value by decreasing the charge transfer and diffusion resistances of the electrodes. Compared to its counterparts in the literature, its Cs value is quite high, but its stability is low, so it can be used in low-cycle applications. [ABSTRACT FROM AUTHOR]