Coordinated Co-NC/CoFe Dual Active Centre Embedded Three-dimensional Ordered Macroporous Framework as Bifunctional Catalyst for Efficient and Stable Zinc-Air Batteries

Developing efficient and stable multifunctional electrocatalyst is very important for zinc-air batteries in practical. Herein, semiconductive spinel CuFe2O4 supported Co-N co-doped carbon (Co-NC) and CoFe alloy nanoparticles were proposed. In this strategy, the three-dimensional ordered macroporous CuFe2O4 support provides rich channels for mass transmission, revealling good corrosion resistance and durability at the same time. ZIF-67 derived Co-NC decoration improves the conductivity of the catalyst. Further, the uniformlydistributed Co-NC and CoFe nanoparticles (C/CF) dramatically promote the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) performance. Accordingly, C/CF@CuFe2O4 catalyst shows remarkable bifunctional electrocatalytic activity, with an ORR half-wave potential of 0.86 V, and an OER over-potential of 0.46 V at 10 mA cm-2. The zinc-air battery using this catalyst exhibits a power density of 95.5 mW cm-2 and a durable cyclability for over 170 h at a current density of 10 mA cm-2, which implies a great potential in practical application.

Структурные преобразования наночастиц Ni-=SUB=-1-x-=/SUB=-Cu-=SUB=-x-=/SUB=-Fe-=SUB=-2-=/SUB=-O-=SUB=-4-=/SUB=- в зависимости от количества ионов Сu

Changes in the structure and properties of magnetic nanoparticles of spinel ferrites Ni1 - xCuxFe2O4 depending of the concentration of Cu ions (0 x 1.0) were studied using Mössbauer spectroscopy. It was found that with an increase in the concentration of Cu ions, the structure of nanoparticles changes from the structure reverse spinel (NiFe2O4) to mixed spinel (CuFe2O4). It is shown that the hydrothermal method synthesis allows one to obtain single-phase nanosized particles with a very narrow distribution in size and perfect magnetic ordering, promising for biomedical applications. A relationship is established between the distribution of cations over the sublattices, the value of the inversion parameter and concentration of Cu ions.

Zinc-triggered photocatalytic selective synthesis of benzyl acetate on inverse spinel CuFe2O4 3D networks: a case of coupled redox photocatalytic reaction

A zinc dopant in CuFe2O4 3D networks triggers the selectivity of benzaldehyde to benzyl acetate via a coupled redox photocatalytic (CRP) reaction.

Fabrication of Bimetal CuFe2O4 Oxide Redox-Active Nanocatalyst for Oxidation of Pinene to Renewable Aroma Oxygenates

This study report on the synthesis of spinel CuFe2O4 nanostructures by surfactant-assisted method. The catalysts were characterized by X-ray diffraction (XRD), laser Raman, transition electron microscope (TEM), scanning electron microscope (SEM), energy dispersive X-ray (EDX), hydrogen temperature programmed reduction (H2-TPR), and Brunauer-Teller-Emmett-Teller (BET) surface area techniques. CuFe2O4 was active for pinene oxidation using tertiary butyl hydroperoxide (TBHP) to pinene oxide, verbenol, and verbenone aroma oxygenates. Under optimized reaction conditions, the spinel CuFe2O4 catalyst could afford 80% pinene conversion at a combined verbenol/verbenone selectivity of 76% within the reaction time of 20 h. The changes in catalyst synthesis solvent composition ratios induced significantly varying redox, phases, and textural structure features, which resulted in various catalytic enhancement effect. Characterization results showed the spinel CuFe2O4 catalyst possessing less than 5 wt% impurity phases, Cu(OH)2, and CuO to afford the best catalytic performance. The CuFe2O4 catalyst was recyclable to up to five reaction cycles without loss of its activity. The recyclability of the bimetal CuFe2O4 oxide catalyst was simply rendered by use of an external magnet to separate it from the liquid solution.