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This study presents the first integrated electrochemical platform (IEP) with point-of-use and portable features for on-site determination of ponceau 4R (RP), amaranth (AM), and tartrazine (TZ) in food by integrating a mass-producible Pt nanoparticles/laser-engraved graphene (Pt NPs/LEG)-based sensing chip and a reusable electrochemical miniaturized workstation. The sensing chip utilizes Pt NPs/LEG with unique architectures as electrode material and exhibits desirable analytical performance towards RP, AM, or TZ with satisfied linear range (0.25-50 μM for RP, AM, and TZ), high sensitivity (7.29 μA μM -1 cm -2 , 7.18 μA μM -1 cm -2 , and 2.02 μA μM -1 cm -2 for RP, AM, and TZ, respectively) and low limit of detection (50 nM, 58 nM, and 204 nM for RP, AM, and TZ, respectively). The sensing chip shows excellent selectivity, high stability, outstanding reproducibility, and acceptable mechanical stability. IEP can be implemented to test RP, AM, or TZ in real samples with satisfactory accuracy and recoveries., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Ultrafine Co 7 Fe 3 nanoparticles embedded in nitrogen-doped porous carbon nanosheets (denoted as Co 7 Fe 3 /NPCSs) are successfully synthesized by utilizing porous plant tissue as a precursor. The morphological, structural, and chemical contents of the Co 7 Fe 3 /NPCSs and other control samples are analyzed by X-ray (powder) diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N 2 adsorption-desorption, Raman spectroscopy, inductively coupled plasma (ICP), and X-ray photoelectron spectroscopy (XPS) techniques. The glucose oxidation and detection performances of each catalyst are evaluated by using cyclic voltammetry and chronoamperometry. The experimental results demonstrate that the electrocatalytic abilities of the resultant catalysts toward glucose oxidation decrease in the order of Co 7 Fe 3 /NPCSs > Co/NPCSs > CoFe/NPCSs > Fe 2 C-Co 3 Fe 7 /NPCSs > Fe 2 C/NPCSs. The experimental results prove that a small number of Fe atoms in Co 7 Fe 3 can increase the number of active Co 4+ sites. Meanwhile, the ultrafine Co 7 Fe 3 nanoparticles uniformly dispersed along the porous carbon nanosheets' surfaces, which further improved the dispersion of the abundant electrochemically available active sites. Due to the synergistic effect of the hierarchical porous structures, high-density active sites and excellent electron conductivity, the optimal Co 7 Fe 3 /NPCSs display the best glucose detection efficiency of all the catalysts examined. For instance, the Co 7 Fe 3 /NPCSs exhibit large sensitivity values (795.28 µA cm -2 mM -1 between 0.001 and 2.20 mM and 401.98 μA cm -2 mM -1 between 2.20 and 14.00 mM), a rapid response time (2.2 s), a low detection limit (1.0 µM), excellent anti-interference toward electroactive molecules, a perfect reproducibility and a superior long-term stability. The Co 7 Fe 3 /NPCSs also exhibit a satisfying efficiency for glucose detection in human serum samples. Finally, our low-cost synthetic strategy can advance research used for designing 3D hierarchical meso/macroporous noble-metal-free catalysts without any tedious steps or templates., (Copyright © 2019 Elsevier Inc. All rights reserved.)

In this work, a novel enzyme-free glucose and hydrogen peroxide (H 2 O 2 ) sensor based on Ni 3 N nanoparticles on conductive 3D graphene aerogels (Ni 3 N/GA) has been successfully synthesized by using hydrothermal reaction, freeze-dried and then calcined under NH 3 atmosphere. The obtained Ni 3 N/GA composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption-desorption isotherms and electrochemical methods. The results show the obtained 3D Ni 3 N/GA composites exhibit excellent electrochemical performance toward glucose oxidation and H 2 O 2 reduction with larger catalytic rate constant K cat value of 3.75 × 10 3  M -1  s -1 and 1.24 × 10 3  M -1  s -1 , respectively. As a glucose sensor, the obtained electrode provides a wide detection range of 0.1-7645.3 μM, fast response time within 3 s, high sensitivity of 905.6 μA mM -1  cm -2 and low detection limit of 0.04 μM. For detection of H 2 O 2 , this prepared sensor offers a wide detection range (5 μM-75.13 mM), fast response time (within 5 s), sensitivity (101.9 μA mM -1  cm -2 ) and low detection limit (1.80 μM). This enzyme-free glucose and H 2 O 2 sensor display satisfactory selectivity, reproducibility and long-term storage stability. Additionally, the sensor can also be used for glucose and H 2 O 2 detection in human blood serum. The results demonstrate that 3D GA nanostructures provide an enviable conductive network for efficient charge transfer and avoid Ni 3 N nanoparticles aggregation, which is advantageous for electrocatalytic applications., (Copyright © 2018 Elsevier B.V. All rights reserved.)

A facile, effective, and environmentally friendly method has been adopted for the first time to prepare tiny Co3O4 nanocrystals embedded carbon matrices without using surfactants, harmful organic reagents or extreme conditions. Structural characterizations reveal that the size-controlled Co3O4 nanocrystals are uniformly dispersed on carbon matrices. Electrochemical measurements reveal that Co3O4-ordered mesoporous carbon (OMC) can more efficiently catalyze glucose oxidation and acquire better detection parameters compared with those for the Co3O4-macroporous carbon, Co3O4-reduced graphene oxide, and free Co3O4 nanoparticles (NPs) (such as: the large sensitivity (2597.5 μA cm(-2) mM(-1) between 0 and 0.8 mM and 955.9 μA cm(-2) mM(-1) between 0.9 and 7.0 mM), fast response time, wide linear range, good stability, and surpassingly selective capability to electroactive molecules or Cl(-)). Such excellent performances are attributed to the synergistic effect of the following three factors: (1) the high catalytic sites provided by the uniformly dispersed and size-controlled Co3O4 nanocrystals embedded on OMC; (2) the excellent reactant transport efficiency caused by the abundant mesoporous structures of OMC matrix: (3) the improved electron transport in high electron transfer rate (confinement of the Co3O4 NPs in nanoscale spaces ensured intimate contact between Co3O4 nanocrystals and the conducting OMC matrix). The superior catalytic activity and selectivity make Co3O4-OMC very promising for application in direct detection of glucose., (Copyright © 2014 Elsevier B.V. All rights reserved.)

A series of highly dispersed bimetallic PtPd alloy nanoparticles (NPs) anchored on reduced graphene oxide (RGO) have been synthesized with the assistance of ionic liquid (IL: [VEIM]BF4). Different ratios of (PtCl6)(2-) and (PdCl4)(2-) ions were firstly attached to IL functionalized graphene oxide (GO) sheets in ethylene glycol (EG), and then the encased metal ions and graphene oxide sheets were reduced simultaneously by EG with the assistance of microwave. The characterization results of scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and X-ray diffraction (XRD) demonstrate that PtPd alloy NPs with small particle sizes are uniformly dispersed on RGO. Electrochemical measurements reveal that PtPd-IL-RGO modified electrode can directly catalyze glucose oxidation and display enhanced current response compared with PtPd-RGO (such as: a response time within 3s, a linear range from 0.1 to 22 mM at 0 V, good reproducibility, considerable stability, and excellent anti-interference to electroactive molecules and Cl(-)). The superior catalytic activity and selectivity make PtPd-IL-RGO nanomaterials very promising for applications in direct detection of glucose., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Polydopamine (PDA)-coated ordered mesoporous carbons (OMCs) are easily prepared through one-step self-polymerization of dopamine on OMCs matrix at room temperature. Pt nanoparticles (NPs) are deposited on OMCs-PDA via a simple chemical reduction. The PDA layer helps to improve the water-solubility and dispersibility of OMCs, and plays a key role in the deposition of uniform and well-distributed Pt NPs. Transmission electron microscopy images reveal that the ultra-fine Pt NPs with an average size of ~1.8 nm are well-dispersed on the surface of OMCs-PDA. The electrocatalytic behavior of OMCs-PDA/Pt modified glassy carbon (GC) electrode is investigated by cyclic voltammetry and current-time methods using hydrogen peroxide (H2O2) and hydrazine (N2H4) as redox probes. Results show that OMCs-PDA/Pt exhibits improved electrocatalytic activity towards H2O2 reduction and N2H4 oxidation compared with OMCs/Pt. The linear electro-redox responses are found for H2O2 and N2H4 in the range of 2-14324 μM and 1-229 μM with the detection limit (S/N=3) of 0.85 μM and 0.51 μM, respectively. In addition, this new nanocomposite modified electrode exhibits high sensitivity, good anti-interference ability, excellent reproducibility and long-term stability., (Copyright © 2013 Elsevier B.V. All rights reserved.)

A simple and facile synthetic method to incorporate copper sulfide (Cu(2)S) nanoparticles inside the mesopores of ordered mesoporous carbons (OMCs) is reported. The Cu(2)S/OMCs nanocomposite was characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption-desorption. The results show that the incorporation of Cu(2)S nanoparticles inside the pores of OMCs does not change the highly ordered two-dimensional hexagonal mesostructure of OMCs matrix. Nonenzymatic amperometric sensor of hydrogen peroxide based on the Cu(2)S/OMCs nanocomposite modified glassy carbon (GC) electrode is developed. Compared with the pristine OMCs modified electrode, the Cu(2)S/OMCs modified electrode displays high electrocatalytic activity towards hydrogen peroxide and gives linear range from 1 to 3030 microM (R=0.9986). The sensor also exhibits good ability of anti-interference to electroactive molecules. The combination of the unique properties of Cu(2)S nanoparticles and the ordered mesostructure of OMCs matrix guarantee the excellent electrocatalysis for hydrogen peroxide. The good analytical performance and low-cost make Cu(2)S/OMC nanocomposite promising for the development of effective sensor for hydrogen peroxide., ((c) 2009 Elsevier B.V. All rights reserved.)

Copper oxide nanoparticles were anchored on sodium dodecyl sulphate (SDS)-functionalized macroporous carbon by utilizing the supramolecular self-assembly of SDS acting as a soft template. The as-prepared composite provides new features of electrocatalytic activities and may hold great promise for the design of environmental sensors. [ABSTRACT FROM AUTHOR]

Abstract: In this work, platinum–palladium alloy nanoparticles/large mesoporous carbon nanocomposites (Pt x Pd y /LMC) (X:Y indicates the different Pt, Pd atomic ratios) are prepared. Transmission electron microscopy, nitrogen adsorption–desorption, X-ray photoelectron spectra and X-ray diffraction were used to characterize the morphology and structure of LMC or its nanocomposites. Hydrogen peroxide and nitrite were employed as the probes to measure the electrochemical applications of Pt x Pd y /LMC. The introduction of Pt x Pd y alloy nanoparticles on LMC matrix facilitates hydrogen peroxide reduction and nitrite oxidation compared to Pt deposited on LMC matrix (Pt/LMC) and LMC. Amperometry was selected to evaluate the electrocatalytic activity of the Pt1Pd1/LMC nanocomposite modified glassy carbon electrode (Pt1Pd1/LMC/GCE). Results indicate that the Pt1Pd1/LMC/GCE shows higher electrocatalytic performance (wider linear range, lower detection limit and higher sensitivity) for hydrogen peroxide reduction and nitrite oxidation than many sensors reported before. The easy fabrication and excellent electrocatalytic capability of the Pt1Pd1/LMC/GCE can be expected to find practical applications to detect other compounds. [Copyright &y& Elsevier]

Abstract: A facile and fast microwave irradiation method was developed to prepare PtPd bimetallic alloy nanoparticles on onion-like mesoporous carbon vesicle (MCV). With MCV acts as a template, its high surface area favors the formation of nanosized PtPd particles. The PtPd/MCV nanocomposite was characterized by transmission electron microscopy (TEM), scanning electron micrographs (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). A nonenzymatic amperometric sensor of glucose based on the PtPd/MCV modified glassy carbon (GC) electrode is developed. Compared with the Pt/MCV nanocomposite, the PtPd/MCV modified electrode displays enhanced current response towards glucose and gives linear range from 1.5 to 12mM. The particular lamellar structure of the MCV results in favorable transport passage for glucose. The modified electrode achieves 95% of the steady-current within 3s. This nonenzymatic glucose sensor also exhibits good ability of anti-interference to electroactive molecules. The fast response and facile preparation method make PtPd/MCV nanocomposite promising for the development of enzyme-free sensor for glucose. [Copyright &y& Elsevier]

Abstract: Hollow carbon spheres (HCSs) are prepared using poly(ionic liquids) (PILs) as a carbon precursor and monodisperse silica particles as a template for the first time. The ILs form a uniform polymer coating on the template surface after polymerization. Carbonization of the coating and the subsequent removal of the template produces porous carbon spheres with a hollow structure. The HCSs possess a high surface area, good conductivity, and porosity suitable for mass transport, and they can be used as a support for Pt electrocatalysts. Pt nanoparticles with an average size of 2.8nm are homogeneously distributed onto the HCSs. The high surface area and unique structure facilitates the fine dispersion of Pt nanoparticles. The obtained Pt/HCSs exhibit a significant catalytic activity for the oxidation of methanol. [Copyright &y& Elsevier]

Abstract: Poly(ionic liquid) (PIL) coated ordered mesoporous carbons (OMCs) were prepared by in situ polymerization of 3-ethyl-1-vinylimidazolium tetrafluoroborate ([VEIM]BF4) monomer on OMCs matrix. PIL on the surface of OMCs can provide sufficient binding sites to anchor the precursors of metal ion. PIL/OMCs were employed as support material for the deposition and formation of ultra-fine Pt nanoparticles, via the self-assembly between the negative Pt precursor and positively charged functional groups of PIL-functionalized OMCs. The combination of the unique properties of each component endows Pt/PIL/OMCs as a good electrode material. Compared with the Pt/OMCs nanocomposite, the Pt/PIL/OMCs modified electrode displays high electrocatalytic activity towards hydrogen peroxide (H2O2) and gives linear range from 1.0×10−7 to 3.2×10−3 M (R =0.999). The Pt/PIL/OMCs responds very rapidly to the changes in the level of H2O2, producing steady-state signals within 4–5s. A high sensitivity of 24.43μAmM−1 and low detection limit of 0.08μM was obtained at Pt/PIL/OMCs modified electrode towards the reduction of H2O2. The improved activity makes Pt/PIL/OMCs nanocomposite promising for being developed as an attractive robust and new electrode material for electrochemical sensors and biosensors design. [Copyright &y& Elsevier]

Abstract: A simple approach for the synthesis of nanosized platinum particles supported on ordered mesoporous carbons (OMCs) was described. For the first time, we successfully used the positively charged poly-(diallydimethylammonium chloride, PDDA) to wrap OMCs and attached Pt nanoparticles (OMCs–PDDA/Pt) via electrostatic interaction. The obtained OMCs–PDDA/Pt nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and electrochemical methods. TEM images reveal that the Pt nanoparticles with an average size of ∼2.88nm are uniformly dispersed on the surface of OMCs–PDDA. The electrocatalytic behavior of OMCs–PDDA/Pt modified glassy carbon (GC) electrode was investigated by cyclic voltammetry, current–time and chronoamperometry methods using hydrazine as a redox probe. The electrochemical results indicate that the OMCs–PDDA/Pt exhibit a good electrocatalytic activity toward the oxidation of hydrazine than that of OMCs/Pt. All these electrochemical measurements confirm the fact that the OMCs–PDDA/Pt nanocomposites may have applications in biological and environmental sensors. [Copyright &y& Elsevier]

As a crucial reaction of electrochemical water splitting, oxygen evolution reaction receives intensive and significant attention in recent years. Here, we develop a type of electrocatalyst with core@shell structure in the form of binary FeNi alloy nanoparticles coated by highly defective nitrogen-doped carbon shell with mesoporous architecture. The composite annealed at 800 °C with Fe/Ni ratio of 1:2 presents extremely high catalytic activity and durability for oxygen evolution in 1.0 M KOH electrolyte, which delivers a low overpotential of 273 mV to achieve a current density of 10 mA cm−2 and a small Tafel slope of 37.82 mV dec−1. We find that appropriate Fe-doping to regulate the surface electronic structure around the active sites is responsible for boosting the electrocatalytic performance. Remarkably, hydroxyl groups introduced along with the Fe doping, acting as an active O radical to facilitate the adsorption of intermediates, are identified as another decisive factor to promote the intrinsic activity for the oxygen evolution reaction. Moreover, such an N-doped carbon shell endows the composite with enriched defects, high conductivity and satisfactory stability, favoring fast electron transfer kinetics. The substantially high catalytic performance of the fabricated binary metallic electrocatalyst makes it potential application in energy storage and conversion devices. Image 1 • 2-methylimidazole is usded for the formation of Fe and Ni complexes. • FeNi alloy nanoparticles coated by nitrogen-doped carbon shell are prepared. • The FeNi composite exhibits high catalytic performance for OER. • Low overpotential of 273 mV is needed to achieve current density of 10 mA cm−2 [ABSTRACT FROM AUTHOR]

[Display omitted] Designing two-dimensional (2D) porous carbon nanosheets is a promising strategy for enhancing the water-splitting activities of non-noble metal catalysts. In this study, we developed a novel method for synthesizing the novel three-dimensional (3D) hierarchically porous iron–nickel (FeNi) nanoparticles encapsulated in boron (B) and nitrogen (N)-codoped porous carbon nanosheets (denoted as FeNi@BNPCNS). Owing to the advantages of morphology and structure of B and N, 10.31 atom % of B/N active centers were successfully doped into the optimal FeNi@BNPCNS-800 nanosheets. FeNi@BNPCNS-800 exhibited better hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) electrocatalytic activities than control catalysts in an alkaline solution. However, the HER and OER electrocatalytic activities of FeNi@BNPCNS-800 were slightly lower than 20 wt% Pt/C and RuO 2. The FeNi@BNPCNS-800||FeNi@BNPCNS-800 electrolyzer achieved 10 mA cm−2 at 1.514 V, which was 73 mV lower than that of 20 wt% Pt/C||RuO 2 electrolyzer (1.587 V). The perfect 3D honeycomb-like architectures, abundant mesopores/defects, and abundant electrocatalytic active sites were attributed to the outstanding water-splitting performances of FeNi@BNPCNS-800 nanosheets. This study provides an efficient strategy for the large-scale, rapid, and low-cost fabrication of 2D porous carbon nanosheets without using any template, surfactant, or expensive raw material, thus presenting a simple approach to design advanced non-noble metal electrocatalysts for water splitting. [ABSTRACT FROM AUTHOR]

Graphical abstract Three-dimensional hierarchically meso-macroporous carbon nanosheets with vast alloy nanoparticles embedding (denoted as Fe 3 Co 7 @PCNSs) were successfully synthesized and acted as high-efficiency water splitting catalyst. Abstract Developing high-efficiency catalysis electrodes towards both HER (hydrogen evolution reaction) and OER (oxygen evolution reaction) is critical to the popularity and practical application of devices for conversion and storage of clean and renewable hydrogen energy by overall water splitting. In this paper, a series of transition metal alloy nanoparticles embedded hierarchically porous carbon nanosheets (denoted as Fe x Co y @PCNSs) have been successfully designed and synthesized. After optimizing the metallic contents in Fe x Co y alloy, Fe 3 Co 7 @PCNSs displays superior water electrolysis performances compared to other control samples and previously reported non-noble metal catalysts. This advance is mainly due to the synergistic effect of increased carbon edges exposure, abundant accessible active sites, and improved electron/mass transport capability of 3D hierarchically porous architecture. More importantly, when Fe 3 Co 7 @PCNSs is applied as both cathode and anode in a two-electrode cell for carrying out the overall water splitting process, it just needs the corresponding cell voltages of 1.667 and 1.707 V to attain the 10 and 20 mA cm−2 current densities respectively. The synthesis of Fe 3 Co 7 @PCNSs confirms the importance of Fe and Co elements in designing catalyst structures. The electrochemical measurements further display the key roles of structural features and metal alloy@C active sites for boosting water splitting performances. [ABSTRACT FROM AUTHOR]

Due to the π–π interaction of graphene (GR) layers, GR sheets tend to aggregate irreversibly to graphite during the application process. In addition, nanoparticles supported on GR layers are easily sandwiched or secluded inside the stacked layers and therefore not efficient exposure for catalysis. To address the irreversible aggregation of GR and increase the utilization efficiency of supported nanoparticles, in this work, porous GR (PGR) was prepared using SiO 2 as a template and used as support for the NiCo 2 O 4 . The porous structure provided larger surface area and more opportunity for the exposure of supported NiCo 2 O 4 . Due to the porous structure of PGR, the NiCo 2 O 4 supported on PGR were not hidden by aggregated GR layers and were highly exposed to target molecules. Compared with NiCo 2 O 4 /GR, the electrocatalytic activity of NiCo 2 O 4 supported on PGR is effectively increased accompanied with the high utilization efficiency of NiCo 2 O 4 supported on PGR. By combination of the catalytic properties of highly exposed NiCo 2 O 4 and structural properties of PGR, the NiCo 2 O 4 /PGR is highly active, cheap and selective noble-metal free catalysts for oxygen reduction reaction (ORR) in alkaline solution. In addition, the ORR activity of NiCo 2 O 4 /PGR is increased accompanied with the decrease of pore size of PGR. NiCo 2 O 4 /PGR is potential efficient and inexpensive noble metal-free ORR catalysts with good long term stability in alkaline solution. [ABSTRACT FROM AUTHOR]

In this work, FeCo nanoparticles encapsulated in graphitic carbon layers are derived by direct pyrolysis of Prussian blue/ZIF-67. First, the Prussian blue nanocubes with size of 100–150 nm are selected as cores for growth of ZIF-67 metal organic frameworks. Subsequent direct pyrolysis of Prussian blue/ZIF-67 in nitrogen atmosphere enables the formation of carbon nanospheres with FeCo nanoparticles embedded into the nitrogen-doped graphitic carbon layers. The encapsulation of FeCo nanoparticles into the nitrogen-doped carbon layers favors the electron penetration from the underlying FeCo nanoparticles to the nitrogen-doped graphitic carbon layers, tuning the electron density and the electronic properties at the carbon overlayers and then promoting the both hydrogen and oxygen evolution reaction activity. By optimizing the ratio between the Prussian blue and ZIF-67, the active and inexpensive carbon layers-encapsulated FeCo nanoparticles achieve high activity towards the hydrogen evolution reaction, exhibiting a low overpotential of 106 mV at 10 mA cm−2 as well as a low Tafel slope of 90.0 mV dec−1. As oxygen evolution reaction electrocatalysts, the carbon layers-encapsulated FeCo nanoparticles deliver an overpotential of 312 mV at 10 mA cm−2 and a low Tafel slope of 40.6 mV dec−1. Severing as both anode and cathode, the carbon layers-encapsulated FeCo nanoparticles show a potential of 1.495 V at 10 mA cm−2 for water splitting, which is close to the noble metal benchmarks of Pt/C and RuO 2 counterparts. The carbon layers-encapsulated FeCo nanoparticles can be used as an attractive replacement for electrocatalytic water splitting. Image 1 • Preparation of carbon layer-coated FeCo by direct pyrolysis of Prussian blue/MOFs. • Promotion of activity by alloying the Fe and Co elements. • High stability and activity of carbon layer-encapsulated FeCo nanoparticles. [ABSTRACT FROM AUTHOR]

Due to the obstacle of sluggish kinetics on cathode of fuel cells and metal–air batteries, developing low-cost and durable electrocatalysts to replace the platinum-based catalysts still remains a grand challenge. Here, we describe a simple self-template approach to synthesize N-doped mesoporous carbon nanocages (FeCo@NC) embedded with FeCo alloy nanoparticles as oxygen reduction reaction (ORR) electrocatalyst. The resulting heterostructure is derived from corresponding PBA@PPy composites, which are pre-prepared by polymerization of polypyrrole (PPy) layer on Prussian blue analogue (PBA) nanocubes. The FeCo alloy nanoparticles with an average particle size of ∼10 nm are well dispersed and confined within the shell of carbon nanocages. Benefiting from the mesoporous structure and the synergetic interaction of binary metals, the optimized FeCo@NC-3-800 electrocatalyst exhibits comparable ORR performances (0.83 V for half-wave potential (E 1/2), 5.323 mA cm−2 for limiting current density (J k)), superior durability and excellent methanol tolerance to the commercial Pt/C (20 wt%). This work provides an appropriate strategy for general, efficient and practical synthesis of more promising non-precious metal electrocatalyst with high ORR activity. Image 1 • A simple approach is developed to synthesize N-doped mesoporous carbon nanocages embedded with FeCo alloy nanoparticles. • The FeCo alloy nanoparticles (∼10 nm) are well dispersed and confined within the shell of carbon nanocages. • The optimized FeCo@NC-3-800 electrocatalyst exhibits highly activity and stability towards oxygen reduction reaction. [ABSTRACT FROM AUTHOR]