Porous CoFe2 O4 /C NRAs supported on nickel foam@NC (denoted as NF@NC-CoFe2 O4 /C NRAs) are directly fabricated by the carbonization of bimetal-organic framework NRAs grown on NF@poly-aniline(PANI), and they exhibit high electrocatalytic activity, low overpotential, and high stability for the oxygen evolution reaction in alkaline media.

Bimetal-Organic Framework Derived CoFe2O4/C Porous Hybrid Nanorod Arrays as High-Performance Electrocatalysts for Oxygen Evolution Reaction

Highly ordered mesoporous copper ferrite (meso-CuFe2O4) with high surface area and large pore size was successfully fabricated and firstly proposed as a heterogeneous Fenton catalyst. It was synthesized through the nanocasting strategy by using KIT-6 as hard template. The morphology and physicochemical properties of meso-CuFe2O4 were characterized by SEM, TEM, XRD, XPS, FT-IR, Raman spectra, etc. The obtained results showed that the surface area and the pore size of meso-CuFe2O4 were 122 m2 g−1 and 9.2 nm, respectively. The meso-CuFe2O4 presented excellent catalytic activity for the degradation of imidacloprid, achieving almost complete removal of 10 mg L−1 imidacloprid after 5 h at the reaction conditions of 0.3 g L−1 catalyst and 40 mM H2O2. Kinetic analysis showed that the degradation of imidacloprid follows the pseudo-first order. The apparent rate constant for meso-CuFe2O4 was 1.0445 h−1, which was 1.5, 2 and 2.5 times than those of meso-CoFe2O4, con-CuFe2O4 and nano-Fe3O4, respectively. The amount of hydroxyl radical (OH) generated was directly proportional to the degradation efficiency of imidacloprid, suggesting the involvement of OH in oxidizing imidacloprid. The obtained results indicated that meso-CuFe2O4 presented the highest activity, which was not only due to its ordered mesoporous structure with high surface area and large pore size, but also assigned to the redox recycle of Fe2+/Fe3+ and Cu+/Cu2+ in meso-CuFe2O4. The special effect of Cu was discussed in terms of the thermodynamically favorable Fe3+ reduction by Cu+, regenerating the active species Fe2+. The meso-CuFe2O4 presented very low iron leaching (<1 ppm) even in acidic condition and retained almost its high catalytic activity after 5 consecutive runs. Besides, meso-CuFe2O4 possessed medium saturation magnetization, which had provided a potential advantage for the recovery and reuse of catalyst.

Magnetic ordered mesoporous copper ferrite as a heterogeneous Fenton catalyst for the degradation of imidacloprid

MOF-templated synthesis of CoFe2O4 nanocrystals and its coupling with peroxymonosulfate for degradation of bisphenol A.

The development of efficient and abundant water oxidation catalysts is essential for the large-scale storage of renewable energy in the form of hydrogen fuel via electrolytic water splitting, but still remains challenging. Based upon eutectic reaction and dealloying inheritance effect, herein, novel Ni-Fe-O-based composite with a unique mesoporous nanowire network structure is designed and synthesized. The composite exhibits exceptionally low overpotential (10 mA cm−2 at an overpotential of 244 mV), low Tafel slope (39 mV dec−1), and superior long-term stability (remains 10 mA cm−2 for over 60 h without degradation) toward oxygen evolution reaction (OER) in 1 m KOH. Moreover, an alkaline water electrolyzer is constructed with the Ni-Fe-O composite as catalyst for both anode and cathode. This electrolyzer displays superior electrolysis performance (affording 10 mA cm−2 at 1.64 V) and long-term durability. The remarkable features of the catalyst lie in its unique mesoporous nanowire network architecture and the synergistic effect of the metal core and the active metal oxide, giving rise to the strikingly enhanced active surface area, accelerated electron/ion transport, and further promoted reaction kinetics of OER.

Eutectic‐Derived Mesoporous Ni‐Fe‐O Nanowire Network Catalyzing Oxygen Evolution and Overall Water Splitting

Preparation of magnetic CoFe2O4-functionalized graphene sheets via a facile hydrothermal method and their adsorption properties

In this paper, a facile synthetic route of cobalt ferrite nanocrystals with narrow size distribution was reported. The key feature of this method involved a very rapid mixing of reducible metal cations with sodium borohydride and simultaneous reduction in a colloid mill, which is followed by a slow oxidation in a separate hydrothermal treatment. The microstructural and magnetic characteristics of the materials were characterized by powder X-ray diffraction (XRD), chemical analysis, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), transmission electron microscopy (TEM), Mossbauer spectroscopy, and magnetometry. The results unambiguously indicated that the obtained products consisted of CoFe2O4 nanocrystals with good monodispersity and high stoichiometry and that, especially, a 9 nm sample exhibited room-temperature superparamagnetism. The formation mechanism of nanocrystals was proposed. It is believed that the extreme forces, to which ...

Facile Synthesis and Characterization of Cobalt Ferrite Nanocrystals via a Simple Reduction−Oxidation Route

The invention relates to a method for preparing micron floccular layered double hydroxides, belonging to the guidance growth special appearance micron LDHs preparation technical field. The method comprises the following steps: firstly, deionized water is used for preparing a salt solution which contains divalent metallic ions M and trivalent metallic ions M , and the salt solution is added with urea and simultaneously added with a guiding agent to prepare mixture; secondly, the mixture is transferred into a high-pressure hydrothermal kettle with a volume of 100 milliliters and provided with a polytetrafluoroethylene liner, and then hydrothermal crystallization is performed for 2 to 8 hours at a temperature of between 80 and 120 DEG C under the condition of standing; and thirdly, products are filtrated and separated, and then washed and dried by the deionized water, and then the micron floccular LDHs are prepared. The method has the advantages that: the method for preparing the micron floccular LDHs is to prepare products with different dimensions and lamina thicknesses through modulation of lamina elements of the LDHs, the mixture ratio of the lamina elements, the concentration of sodium alginate, the reaction time and temperature, so as to control the structure and the appearance of the products. The process is a urea decomposition and hydrothermal crystallization one-step synthesis method with participation of the guiding agent, is simple and convenient to operate, has no pollution, has low preparation cost and energy consumption, and is favorable for industrial application.

Method for preparing micrometre level flocculus shaped layered bi-metal hydroxide

Nickel ferrite nanocrystals with narrow distribution of crystallite sizes have been obtained through a novel and facile reduction–oxidation approach. The as-prepared samples with the stoichiometric...

Facile Preparation of Nickel Ferrite Nanocrystals via a Novel Reduction-Oxidation Route

A preparation method which uses hydrotalcite precursor method for producing Si substrate porous ferrite film belongs to the technical field of metal-oxide film preparation, the Si substrate after sulfur treatment is completely contacted with salt ion solution, then the Si substrate attached with salt ion is put into the high-pressure reaction kettle with a polyfluortetraethylene liner for hydro-thermal synthesis crystallization so as to produce uniform and compact hydotalcite film which is then sintered with high temperature to be transferred into the coextruded film of spinel type ferrite and metal oxide, at last, after metal oxide selectively is eliminated, porous ferrite film can be obtained; the method has the advantages that the magnetic domain structure of the magnetic film is uniform so as to improve the magnetic performance, the purpose of controlling the porous ferrite film without magnetic performance can be reached, the operating method is simple, the preparation cost and the energy consumption are low and the film is beneficial to the industrialized application.

Guoli Fan

Papers

Facile Synthesis and Characterization of Cobalt Ferrite Nanocrystals via a Simple Reduction−Oxidation Route

Method for preparing micrometre level flocculus shaped layered bi-metal hydroxide

Facile Preparation of Nickel Ferrite Nanocrystals via a Novel Reduction-Oxidation Route

Method for manufacturing silicon base body stephanoporate ferrite thin film with hydrotalcite forerunner method