Graphene-like Sheets Research Articles

Nanoscale/microscale porous graphene-like sheets derived from different tissues and components of cane stalk for high-performance supercapacitors

Different biomass components have different effects on the microstructures and physicochemical properties of biocarbons. And the properties of biocarbons still need to be further improved. Nanoscale/microscale graphene-like sheets are synthesized with KOH as micropore-forming agent, $$\hbox{Fe}(\hbox{NO}_{3})_{3}\cdot \hbox{9}\,\hbox{H}_{2}\hbox{O}$$ as mesopore-forming agent and graphite catalyst. It is systematically researched to get the effects of biomass components on them. Cane sugar can form flat graphene-like nanosheets with high conductivity. Their performance drops sharply at $$100\,\hbox{A g}^{-1}$$ , indicating that biocarbons need a support of carbon skeleton to operate normally at high current density. Bagasse pith contains amount of cellulose and hemicellulose, which are good for forming pores. Bagasse pith-derived graphene-like sheets possess large specific surface area ( $$2923.58\,\hbox{m}^{2}\,\hbox{g}^{-1}$$ ), high specific capacitance ( $$514.14\,\hbox{F g}^{-1}$$ at $$0.3\,\hbox{A g}^{-1}$$ and $$372.57\,\hbox{F g}^{-1}$$ at $$100\,\hbox{A g}^{-1}$$ ) and high energy density. Due to homogeneous coated doping with graphene-like nanosheets, sugarcane pith-derived graphene-like sheets possess low impedance ( $$\text{R}_{\mathrm{s}}=0.02\,\Omega $$ ), high rate capability (maintained 82.34% from 0.3 to $$100\,\hbox{A g}^{-1}$$ ) and high cycling stability (maintained 101.51% after 5000 cycles), which is better than lots of graphene doping. Sugarcane skin contains more lignin which has hexagonal carbon rings. The graphitization extent of sugarcane skin-derived graphene-like sheets is significantly high. The results provide references to select carbon precursors, and show a novel graphene-like doping method which is suitable for different materials and various fields.

Iron doped effects on active sites formation over activated carbon supported Mn-Ce oxide catalysts for low-temperature SCR of NO

To clarify the Fe doped effects over activated carbon (AC) supported Mn-Ce oxide catalysts and study the influence of Fe addition on the AC, several Mn/Ce/Fe mixed oxide catalysts prepared via an impregnation method supported on AC were investigated for low-temperature selective catalytic reduction (SCR) of NO with NH3. The Mn-Ce-Fe/AC catalyst with 5% (mass ratio) loading exhibited the highest catalytic activity and yielded above 90% NO conversion at 125 °C with a space velocity of 12,000 h−1. The Fe addition could obviously reduce the destruction of AC surface area. Also, the metal ions could insert into graphite crystallite structures of AC, splitting it into smaller graphene-like sheets. After doping with Fe species, the relative ratios of Mn4+/Mnn+, Ce3+/Cen+ and the surface adsorbed oxygen greatly enhanced in Mn-Ce-Fe/AC catalyst. Additionally, both weak acid and medium acid amount increased significantly after the Fe species introduced in Mn-Ce/AC, which could be attributed to the more exposed active sites of acid due to Fe species or its influence on Mn/Ce species. Relying on the obtained results, a L-H mechanism was proposed, owing to the Fe doping, the average valence state of Mn ions and surface adsorbed oxygen both increased on the Mn-Ce-Fe/AC catalyst, specially accompanying with the surface acid sites promotion, therefore remarkably promoting the denitration efficiency due to all the cumulative effect.

Structural and electronic properties of BN co-doped and BN analogue of twin graphene sheets: A density functional theory study

Twin graphene is a new allotrope of carbon that exhibits semiconducting properties. In the present work, structural and electronic properties of BN co-doped twin graphene and twin graphene-like BN-C sheets were studied by density functional theory. The thermal stability of these sheets was confirmed by calculation of the cohesive and formation energies. Negative cohesive and formation energies depict that BN substitution process in twin graphene sheet is exothermic and all twin graphene-like BN-C sheets are thermodynamically feasible. It is found that BN doping modifies significantly atomic structure and electronic properties of twin graphene. The energy band gaps of graphene-like BN-C sheets increase with increasing the number of BN pairs. When all C atoms in pristine twin graphene were substituted by BN pairs, the pristine twin graphene changes from semiconductor to insulator. Our results suggest new two-dimensional structures with desired energy band gap for use in nanoelectronic devices.

Cover Feature: Preparation of Biomass‐Based Porous Carbons with High Specific Capacitance for Applications in Supercapacitors (ChemElectroChem 14/2019)

The Cover Feature depicts a sustainable high-performance carbon material for supercapacitors prepared through the simple and green thermal pyrolysis of orange peel as the raw material and KOH as an activator. The prepared supercapacitors show that the hierarchical porous carbon with ultrathin graphene-like sheets offer excellent electrochemical performance. More information can be found in the Article by H. Shen et al. on page 3599 in Issue 14, 2019 (DOI: 10.1002/celc.201900395).

Controlling synthesis of nitrogen-doped hierarchical porous graphene-like carbon with coral flower structure for high-performance supercapacitors

In this work, nitrogen-doped hierarchical porous graphene-like carbon (NCFC) with coral flower structure is synthesized by an eco-friendly and inexpensive template carbonization method, with cellulose acetate (CA) as carbon precursor, MgO as template, and urea as nitrogen agent. The as-synthesized NCFC features loose coral flower composed of ultra-thin graphene-like sheets and has a high specific surface area of 937 m2 g−1. As the electrode material for supercapacitors, the NCFC shows a high capacitance of 333 F g−1 at 1 A g−1 in 1 mol L−1 H2SO4 electrolyte and a good rate performance (the specific capacitance at 10 A g−1 retains 84% relative to 1 A g−1), and excellent cycle stability with 100% capacitance retention after 10,000 cycles. The symmetric supercapacitor (SSC) was assembled by using NCFC in 1 mol L−1 H2SO4 electrolyte. The device exhibits the maximum energy density of 21 W h kg−1 at a power density of 750 W kg−1 in a potential window of 0 to 1.4 V. Our work is expected to pave a new way for scale-up production of high-performance graphene-like carbon from natural cellulose with a simple, eco-friendly, and low-cost method.

Structural, electronic and optical properties of graphene-like nano-layers MoX2(X:S,Se,Te): DFT study

Using the first principle calculations, the structural, electronic and optical properties of the monolayer graphene-like MoX2 sheet are calculated. Our results show that the chalcogenide atoms in the stability and the lattice parameters of the MoX2 sheet have a key role, although it is known that the electronic properties are more dependent on the metal atoms in these sheets. Our data also confirm semiconductor behavior of the MoX2 monolayers with direct band gap for S, Se and Te chalcogenides. Compared with the bulk compounds, they have similar structural properties but represent unique electronic and optical properties that can be used in nano-devices, nano-electronics and so on. In this work, the investigation of the chalcogenide atoms role in modifying the optical properties of these single-layer sheets, such as absorption and refraction coefficients, is carried out; the dielectric constant plays an important role. We also try to study the possibility of using these compounds on the solar energy industries and optical devices.

X-Ray Diffraction Evaluation of the Average Number of Layers in Thermal Reduced Graphene Powder for Supercapacitor Nanomaterial

Graphene oxide (GO) can be partially reduced to graphene-like sheets by removing the oxygen-containing groups and recovering the conjugated structure. In this work, the thermal reduction of GO powder has been carried out using back pumping vacuum pressures and investigated employing X-ray diffraction analysis. The experimental results of estimating the number of graphene layers on the reduced powder at various temperatures (200 – 1000 °C) have been reported. Electrical changes have been produced in a graphene oxide with the vacuum reduction process. This study has shown that the ideal processing temperature for reducing graphene oxide nanomaterial was about 400 °C. It has also been shown that at 600 °C the number of layers in the reduced nanomaterial increased. The internal series equivalent resistance (ESR) has been improved substantially with the vacuum thermal treatment even at temperatures above 400 °C. ESR was reduced from 95.0 to about 13.8 Ω cm2 with this processing. These results showed that the process can be applied to the reduction of graphene oxide to produce supercapacitor nanomaterials. The advantage of employing this method is that the processing is a straightforward and low cost thermal treatment that might be used for large amount of nanocomposite material.

Stable and hard hafnium borides: A first-principles study

We investigate the stability of hafnium borides at zero pressure via the evolutionary crystal structure prediction and first-principles calculations. Our results indicate that the well-known P6/mmm-HfB2 is the only thermodynamically stable phase at zero temperature and pressure, and two more phases (Pnma-HfB and Fm3¯m-HfB12) become thermodynamically stable at higher temperatures. We compute the mechanical properties including bulk, shear and Young’s moduli, Vickers hardness, and fracture toughness for all stable and metastable hafnium borides (∼30 phases) and then study in detail the effect of boron concentration and topology of B-sublattice on their mechanical properties. We show that not only the concentration of boron, but also the topology of the boron sublattice is important for the mechanical properties of hafnium borides. Among the predicted stable and low-energy metastable hafnium borides, the highest possible hardness is exhibited by P6/mmm-HfB2 with graphenelike boron sheets and by phases with 3D boron networks and high B/Hf ratios (e.g., Pnnm-HfB5 and Fm3¯m-HfB12).

Stacking stability of C2N bilayer nanosheet

In recent years, a 2D graphene-like sheet: monolayer C2N was synthesized via a simple wet-chemical reaction. Here, we studied the stability and electronic properties of bilayer C2N. According to a previous study, a bilayer may exist in one of three highly symmetric stacking configurations, namely as AA, AB and AB′-stacking. For the AA-stacking, the top layer is directly stacked on the bottom layer. Furthermore, AB- and AB′-stacking can be obtained by shifting the top layer of AA-stacking by a/3-b/3 along zigzag direction and by a/2 along armchair direction, respectively, where a and b are translation vectors of the unit cell. By using first-principles calculations, we calculated the stability of AA, AB and AB′-stacking C2N and their electronic band structure. We found that the AB-stacking is the most favorable structure and has the highest band gap, which appeared to agree with previous study. Nevertheless, we furthermore examine the energy landscape and translation sliding barriers between stacking layers. From energy profiles, we interestingly found that the most stable positions are shifted from the high symmetry AB-stacking. In electronic band structure details, band characteristic can be modified according to the shift. The interlayer shear mode close to local minimum point was determined to be roughly 2.02 × 1012 rad/s.

Graphene like Porous Carbon Sheets Derived from Hibiscus Cannabinus As a Versatile Electrochemical Energy Storage Material

In recent years, energy storage devices such as supercapacitors (SC) and Li-ion batteries (LIB) have attracted worldwide interest due to their critical role in replacing the conventional fuels in the transportation sector and also owing to their promising electro-chemical characteristics like long cycle life, high energy density, high power density and low toxicity [1]. In LIBs and SCs, carbon electrode material is arguably an important component and plays a pivotal role in the device performance. However, development of low cost carbon electrode materials with improved energy density and long cycle stability are the great challenges to meet the increasing demands of upcoming electric vehicle technology. Various carbon materials, such as activated carbon, mesoporous carbon, graphene and carbon nanotubes have been extensively studied as electrode materials. However, there are certain limitations using these materials for commercial applications due to their inappropriate pore structure, high cost, tedious synthesis conditions etc. [2]. Graphene-like porous carbon sheets (GPCSs) have recently been viewed as the outstanding electrode materials for high rate electrochemical storage devices such as supercapacitors and Li-ion batteries because the 2D porous carbon sheets can integrate the high conductivity as well as high porosity to promote the facile diffusion of both ion transport and electron transfer. Herein, synthesizing graphene like porous carbon sheets from a renewable biomass waste (Hibiscus cannabinus sticks) is of great importance in lowering the production costs and also promoting environmental protection. The relationship between structure of the GPCS-X (X represents the concentration of activation agent) and its electrochemical performance at different concentration of activating agent is explored in detail. The resulting porous carbon sheets possesses excellent textural parameters with a high specific surface area of 2308 m2/g, highly ordered graphitic carbon with a ID/IG ratio of 0.315 which is confirmed by BET, Raman, HR-TEM (Figure 1a and 1b) etc. While being used as supercapacitor application, the GPCS electrode exhibits a high specific capacitance of 240 F/g at 1A/g, excellent rate capability (84% capacity retention at 50 A/g) and also shows outstanding cyclic stability (92% capacitance retention after 25,000 cycles) in aqueous electrolyte. When tested in organic electrolyte with an extended voltage window, the electrode exhibits symmetric charge-discharge profiles as shown in figure 1c. Also, for Li-ion battery application, GPCS electrode material as shown in figure in 1d displayed a high reversible capacity (1050 mAh/g at 100 mA/g), excellent rate performance (230 mAh/g at 5000 mA/g), and good cycling stability (72% capacitance retention after 400 cycles). The excellent electrochemical performance of GPCS electrode material can be attributed to the high electrical conductivity of the graphene network along with high specific surface area. These results demonstrate a facile, low-cost, eco-friendly design of electrode materials for energy storage applications. Figure 1 (a) FE-SEM and (b) HR-TEM images of GPCS material (c) Charge-Discharge profiles for Supercapacitor application and (d) Rate comparison for Li-ion battery application.

Point-Defect-Rich Carbon Sheets as the High-Activity Catalyst Toward Oxygen Reduction and Hydrogen Evolution

Exploring a novel approach for the synthesis of oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) catalysts with inexpensive and high-activity is desirable. Herein, we report a bubble templating method to synthesize the graphene-like mesoporous carbon sheets with point defects as ORR/HER bifunctional electrocatalysts. The typical product shows excellent ORR performance including the positive onset potential (740 mV) and high diffusion-limiting current density (4.07 mA cm−2). Along with small Tafel slopes, the overpotential is determined to be about −453 and −378 mV at 10 mA cm−2 in both alkaline and acidic media, which suggests a good candidate for HER reaction as well. The superior catalytic activities are derived from the abundant point defects on the mesoporous carbon sheets surface, especially the existence of pyridinic and pyrrolic nitrogen species. This study may be an alternative route to prepare the novel functional materials for the applications of ORR and HER.

Effect of various defects on mechanical and electronic properties of zinc-oxide graphene-like structure: A DFT study

In current study ab-initio based density functional theory (DFT) calculations were employed to determine the effect of different types of defect including the point (Stone-Wales (SW) and atom vacancies) and shape defects on mechanical and electronic properties of zinc oxide (ZnO) graphene-like sheet. Also, the density of states calculations (DOS) were done to give a better understanding of the electronic behavior of this structure under applied defects. With this purpose, different defects were applied to the surface of the ZnO graphene-like sheet and Young's modulus was calculated theoretically. Results showed that all applied defects had a negative effect on Young's modulus. SW defect had the lowest effect on Young's modulus among point defects. In terms of vacancy defects, increasing in the number of extracted atoms decreased modulus reversely. We also found from vacancy defects that extracting Zn atom decreased the properties more than extracting oxygen atom. So Zn atom has a higher effect on ZnO graphene-like sheet strength and stability compared to oxygen atom. The lowest obtained Young's modulus occurred in three atom vacancy with two missed Zn atoms. Furthermore, circular and square shape defects with various diameters were created on ZnO graphene-like sheet and Young's modulus was again considered.

Structural, chemical and electronic differences between bare and nitrogen-doped carbon nanoparticles

Comparisons between bare carbon (CPs) and nitrogen-doped carbon nanoparticles (N-CPs) synthesised using hydrothermal reaction are carried out. It was found that hydrothermal reaction of citric acid yields graphene-like sheets, while the nitrogen doping using ethylenediamine resulted in amorphous polymeric ball-like hydrocarbons devoid of any aromatic rings. Although the Fourier transform infrared spectroscopy, Raman spectroscopy and nuclear magnetic resonance spectroscopy indicate the presence of carbon–carbon double bonds (C=C), and the ground states of both materials are very deep (> 7.8 eV) as measured by ultraviolet photoelectron spectroscopy. This indicates the conjugation is very short. This is supported by the fact that both materials are UV blue emitting peaking at 375 nm probably originating from C=C.

Nickel loaded graphene-like carbon sheets an improved electrocatalyst for hydrogen evolution reaction

Abstract In this article, we successfully prepare Ni loaded graphene-like carbon sheets which act as an efficient electrocatalyst for hydrogen evolution reaction. The as-prepared electrocatalysts show an ultrathin rose petal-like carbon sheets structure loaded with micro and nano-sized Ni particles. The electrocatalytic activity of Ni loaded carbon sheets electrocatalysts are studied in 1 M KOH solution. Ni-GCS-2 shows overpotential of 0.205 V (vs RHE) at a current density of 10 mA cm−2 with better stability for 4 h continuously and lower Rct. Ni-GCS-2 shows only 15% loss for HER after 4 h. The effect of Ni on electrocatalytic performance was investigated. The Ni Nano particles are the active sites for the reaction and graphene-like carbon sheets facilitate electron transport due to their conductive nature. This study showed that Ni-GCS-2 is better in performance as compared to other as-prepared electrocatalyst and previously studied Ni-based electrocatalysts.

Generating Oxygen Vacancies in MnO Hexagonal Sheets for Ultralong Life Lithium Storage with High Capacity.

The polar surface of (001) wurtzite-structured MnO possesses substantial electrostatic instabilities that facilitate a wurtzite to graphene-like sheet transformation during the lithiation/delithiation process when used in battery technologies. This transformation results in cycle instability and loss of cell efficiency. In this work, we synthesized MnO hexagonal sheets (HSs) possessing abundant oxygen vacancy defects (MnO-Vo HSs) by pyrolyzing and reducing MnCO3 HSs under an atmosphere of Ar/H2. The oxygen vacancies (Vos) were generated in the reduction process and have been characterized using a range of techniques: X-ray absorption fine structure, electron-spin resonance, X-ray absorption near edge structure, Artemis modeling, and R space Feff modeling. The data arising from these analyses inform us that the introduction of one Vo defect within each O atom layer can reduce the charge density by 3.2 × 10-19 C, balancing the internal nonzero dipole moment and rendering the wurtzite structure more stable, so inhibiting the change to a graphene-like structure. Density function theory calculations demonstrate that the incorporation of Vos sites significantly improves the charge accumulation around Li atoms and increases Li+ adsorption energies (-2.720 eV). When used as an anode material for lithium ion batteries, the MnO-Vo HSs exhibit high specific capacity (1228.3 mAh g-1 at 0.1 A g-1) and excellent cell cycling stabilities (∼88.1% capacity retention after 1000 continuous charge/discharge cycles at 1.0 A g-1).

Novel MAB phases and insights into their exfoliation into 2D MBenes.

Considering the recent breakthroughs in the synthesis of novel two-dimensional (2D) materials from layered bulk structures, ternary layered transition metal borides, known as MAB phases, have come under scrutiny as a means of obtaining novel 2D transition metal borides, the so-called MBenes. Here, based on a set of phonon calculations, we show the dynamic stability of many Al-containing MAB phases, MAlB (M = Ti, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc), M2AlB2 (Sc, Ti, Zr, Hf, V, Cr, Mo, W, Mn, Tc, Fe, Rh, Ni), M3Al2B2 (M = Sc, T, Zr, Hf, Cr, Mn, Tc, Fe, Ru, Ni), M3AlB4 (M = Sc, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe), and M4AlB6 (M = Sc, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo). By comparing the formation energies of these MAB phases with those of their available competing binary M-B and M-Al, and ternary M-Al-B phases, we find that some of the Sc-, Ti-, V-, Cr-, Mo-, W-, Mn-, Tc-, and Fe-based MAB phases could be favorably synthesized under appropriate experimental conditions. In addition, by examining the strengths of various bonds in MAB phases via crystal orbital Hamilton population and spring constant calculations, we find that the B-B and then M-B bonds are stiffer than the M-Al and Al-B bonds. The different strengths between these bonds imply the etching possibility of Al atoms from MAB phases, consequently forming various 2D MB, M2B3, and M3B4 MBenes. Furthermore, we employ the nudged elastic band method to investigate the possibility of the structural phase transformation of the 2D MB MBenes into graphene-like boron sheets sandwiched between transition metals and find that the energy barrier of the transformation is less than 0.4 eV per atom.

Nitrogen and sulfur co-doped graphene-like carbon sheets derived from coir pith bio-waste for symmetric supercapacitor applications

An efficient synthesis of nitrogen and sulfur co-doped graphene-like carbon sheets from coir pith bio-waste through the mechanical activation method is reported in this study. The structural characterization reveals the presence of a graphene-like carbon sheet, which is uniformly doped with nitrogen and sulfur atoms in a carbon network. The nitrogen and sulfur co-doped graphene-like carbon sheets (NSG) has amorphous nature with a defective porous carbon structure and it depicts the maximum specific capacitance of 247.1 F g−1 at 0.2 A g−1 and a capacitance retention of 75.2% at 10 A g−1. The synthesized NSG-10 registered a maximum energy density of 33.6 Wh kg−1 at 0.2 A g−1 and shows the maximum power density of 4220.0 W kg−1 at 10.0 A g−1. Furthermore, a symmetric supercapacitor (SSC) device shows the device capacitance of 33.7 F g−1 at 0.2 A g−1 when operated at 1.0 V. The SSC device gives a capacitance retention of 82.0% at 10 A g−1 and reveals an excellent stability with no losses in capacitance with 100% columbic efficiency over 10,000 cycles. The results suggest that the proposed methodology is a simple and unique way to synthesize heteroatoms-doped graphene-like carbon sheets from biomass materials for a supercapacitor.

One-pot self-assembly of sisal-like TiO2 on graphene-like carbon sheets via a novel two-phase interface-facilitated route

A Sisal-Like TiO2/Graphene-Like Carbon Sheets (SL-TiO2/GLCSs) composite was fabricated via a facile one-pot self-assembling route at a two-phase interface. The ingenious P123 was introduced to serve a dual function of carbon precursor and structure-directing agent, which first assembled at the water/oil interfaces and subsequently was in situ carbonized to GLCSs. Then the sisal-like TiO2 grew gradually on the GLCSs along the preferred direction. This process shows several advantages such as simple processes, mild condition, low cost and good combination of SL-TiO2 and GLCSs. The combination of SL-TiO2 with GLCSs significantly helps the adsorption of substrates as well as promotes electron-hole pair separation, exhibiting good photocatalytic activity towards degradation of methylene blue (MB) compared to the pristine SL-TiO2 and commercial P25. This strategy opens up new perspectives for fabricating novel composites of nanooxides/GLCSs.

Band structures tuning for 2D porous graphene-like sheets with specific CN stoichiometric ratio: Theoretical investigation

2D porous graphene-like sheets with specific CN stoichiometric ratio (h-C2N and h-C5N2) were theoretically investigated based on DFT method. The calculated results show h-C2N and h-C5N2 are both semiconductors with direct band gap 1.72 and 1.10 eV. The CBM positon for h-C2N is high, but the potential positions for h-C5N2 are very low. h-C2N is predicted as good photo- or electro-catalyst to produce hydrogen or CO2 reduction but h-C5N2 is not. Defects construction and tailoring 2D h-C2N and h-C5N2 sheets to 1D nanoribbons were used to tune the band structures. The defective derivatives are n-type semiconductor with two doping levels contributed by O atoms. The doping levels could capture electrons as trap levels and O atoms could coordinate metal to obtain single-atom catalyst. 1D nanoribbons show bigger band gaps and higher CBM potential position than corresponding 2D sheets, which is thought to show better properties on photo- or electro-catalysis.

Increased activity of nitrogen-doped graphene-like carbon sheets modified by iron doping for oxygen reduction

Rational design and synthesis of Fe-N-codoped carbon materials are promising for replacing commercial Pt/C for oxygen reduction reaction (ORR). Herein, we develop a simple two-step pyrolysis approach to synthesize highly active Fe-N-codoped graphene-like carbon sheets (FeNGC) with active Fe-N-based species for ORR. In this strategy, two-dimensional nitrogen-doped graphene-like carbon sheets (NGC) with a high N-doping level (8.1 at%) and abundant mesoporosity (3.8 nm) are firstly synthesized by co-pyrolysis of biomass carbon source and dicyandiamide, in which dicyandiamide simultaneously serves as a trifunctional role of in situ reaction template, nitrogen source and porogen. Secondly, FeNGCs are prepared by additional iron doping of NGC at high temperatures, in which sheet-like structure is in favor of increased accessibility of N-functional groups to more Fe atoms, thus giving rise to formation of high-density Fe-N-based active sites. The optimized catalyst synthesized at 950 °C (FeNGC-950) demonstrates significantly increased ORR activity with a dominant 4e− reduction process compared to pure NGC in alkaline and acidic solutions, which evidently shows the comparable activity to Pt/C due to the synergy of simultaneously optimized structures and multi-active sites. Moreover, FeNGC-950 has better long-term stability and methanol tolerance than Pt/C both in alkaline and acidic electrolytes. The present strategy paves a new venue to design and prepare various metal-doped carbon materials with great potentials in energy applications.