Porous N-doped Graphene Research Articles

On-pot fabrication of binder-free composite of iron oxide grown onto porous N-doped graphene layers with outstanding charge storage performance for supercapacitors

An effective one-step electrochemical method was developed to synthesize three-dimensional N-doped porous graphene/magnetite nanoparticles hybrid onto Ni foam (Fe3O4@3D-NPG/NF electrode). In this method, 3D nitrogen-doped porous graphene layers are electrophoretically deposited onto Ni foam, accompanied by the simultaneous in situ electrochemical deposition (ECD) of magnetite particles onto 3D-NPG layers. For comparison, Fe3O4 particles and N-doped graphene were separately deposited onto Ni foam, and pristine Fe3O4/NF and 3D-NPG/NF electrodes were fabricated. The structure, composition and morphology of the fabricated electrode materials were systematically characterized by XRD, FT-IR, FE-SEM, Raman, TEM, BET, and TGA/DSC techniques. The formation mechanism of Fe3O4@3D-NPG hybrid through EPD/ECD was proposed and described in detail. The charge storage capabilities of the fabricated electrodes were analyzed as the supercapacitor electrode. The results GCD tests revealed that Fe3O4@3D-NPG electrode is able to deliver specific capacity value of 715 F g−1 at 2 A g−1 and cycle life of 94.3% after 5000 GCD cycles, where the pristine Fe3O4/NF electrode delivered only specific capacity of 219 F g−1 and 77.6% capacity retention. These findings implicated the positive synergistic effects between Fe3O4 and 3D-NPG in the hybrid electrode to exhibit higher supercapacitive performance. This simple strategy could find practical uses in the large-scale fabricating Fe3O4@3D-NPG electrode.

表面氧化构建PPy@VNO/NG核壳结构作为长寿命超级电容器负极材料

Vanadium nitride (VN)-based materials have been investigated as negative electrode materials for supercapacitors (SCs) owing to their high theoretical capacitances and suitable negative potential windows. However, viable VN-based negative electrode materials suffer from irreversible electrochemical oxidation of the soluble vanadium species, leading to rapid capacitance fading when operated in aqueous electrolytes. Developing a versatile approach to enhance the stability of VN in aqueous electrolytes is still a challenge. Here, an interface engineering strategy is developed to intentionally introduce surface nanolayers of vanadium oxides (VOX) as a reactive template on the VN surface to formulate well-designed polypyrrole@VNO (Ppy@VNO) core-shell nanowires (NWs) incorporated into a 3D porous N-doped graphene (NG) hybrid aerogel as a durable negative electrode for SCs. Experimental and theoretical investigations reveal that the in-situ constructed Ppy@VNO core-shell host can offer more efficient pathways for rapid electron/ion transport and accessible electroactive sites. Most importantly, a reversible surface redox reaction is realized through the transformation of the valence state of V, and a long cyclic stability is achieved. The Ppy@VNO/NG hybrid aerogel can deliver a high specific capacitance of 650 F g−1 at 1 A g−1 with approximately 70.7% capacitance retention (up to the twenty fold current density), and an excellent cycling stability without any capacitance de cay after 10,000 cycles at both low and high current densities (1 and 10 A g−1, respectively). This work paves the way for the development of advanced electrode materials for SCs.

Application of Carbon Materials in Aqueous Zinc Ion Energy Storage Devices.

Zinc-ion storage is a promising electrochemical energy field due to loads of its advantages like easy preparation, environmental friendliness, high safety performance, and high capacity. Carbon materials have been widely studied for zinc-ion storage due to their extraordinary properties such as earth-abundancy, low-cost, good electrical conductivity, various structures, and good stability. This article reviews some widely used carbon materials in zinc ion storage devices, including hollow carbon spheres, activated carbon, N-doped porous carbon, graphene, and carbon nanotubes. The unique roles and advantages of these carbon materials in both zinc ion supercapacitors and zinc ion batteries are emphasized. Characteristics and functionalizations of different carbon materials are also comparatively discussed in view of zinc-ion energy storage devices. Finally, some challenges and perspectives of carbon materials in zinc-ion energy storage are outlined.

Synergistic Effect of N-Doped sp2 Carbon and Porous Structure in Graphene Gels toward Selective Oxidation of C-H Bond.

N-doped carbon materials represent a type of metal-free catalyst for diverse organic synthetic reactions. However, single N-doped carbon materials perform insufficiently in the selective oxidation reaction of C-H bond compared with metal catalysts or multielement co-doped materials. There are a few reports on the application of three-dimensional (3D) carbon materials in such a reaction. Besides, the relationship between the well-developed porous structures, heteroatom doping, and their catalytic performance is unclear. In this study, 3D porous N-doped graphene aerogel catalysts with high activity and selectivity for the C-H bond oxidation under mild reaction conditions have been synthesized through a two-step method. Systematic studies on the dosage of N sources, pyrolysis temperature, and their influences on the catalytic performances have been evolved. Moreover, solid evidence of the synergistic effect of sp2 C atoms adjacent to the N atoms and porous structure promoting the performance has been provided in this work.

Fe3C/Fe nanoparticles embedded in N-doped porous carbon nanosheets and graphene: A thin functional interlayer for PP separator to boost performance of Li-S batteries

The sluggish conversion and severe shuttle effect of soluble polysulfides in lithium-sulfur (Li-S) cells are still the urgent problems for boosting their practical application, although they have been considered as one of the most promising candidates for the advanced energy storage devices in the near future. Herein, a heterostructural Fe3C/Fe@NC/G nanocomposite, in which the Fe3C and Fe nanoparticles are well-embedded in the N-doped porous carbon nanosheets and graphene substrate, is firstly prepared by a novel two-steps temperature-controlled calcination, and then it is used to modify the conventional PP separator. The thin Fe3C/Fe@NC/G coating layer can not only effectively block the diffusion of dissolved polysulfides through the physical barrier and chemical binding, but also accelerates the redox conversion of polysulfides as a functional catalyst. As a result, a Li-S cell prepared by this modified separator and a S/KB composite with a high sulfur content of 70 wt% in the final cathode displays high discharge capacity and good cycling capability, with a high specific capacity of ~ 1489 mAh g−1 at 0.1C and a capacity decline rate of ~ 0.062% per cycle during 500 cycles at 1.0C, respectively. Furthermore, this functional separator can enable a Li-S cell with a high sulfur areal loading of 5.0 mg cm−2 to perform well, with a high specific capacity of 618 mAh g−1 at 0.1C and a good cycling stability. This facile and effective strategy will provide better insight to develop high-energy Li-S batteries, from the perspective of improvement of kinetics conversion and decrease of shuttle effect of the polysulfides simultaneously.

Co/Co9S8@carbon nanotubes on a carbon sheet: facile controlled synthesis, and application to electrocatalysis in oxygen reduction/oxygen evolution reactions, and to a rechargeable Zn-air battery

A facile strategy to fabricate Co/Co9S8 nanoparticles-encapsulated in carbon nanotubes, on an N-doped porous graphene sheet (Co/Co9S8@CNTs) via pyrolysis of a mixture of Co(NO3)2, melamine and l-cysteine is reported.

Hierarchical NiCo2Se4 nanoneedles/nanosheets with N-doped 3D porous graphene architecture as free-standing anode for superior sodium ion batteries

In order to cope with the problem of insufficient lithium metal reserves, sodium ion batteries (SIBs) are proposed and extensively studied for the next-generation batteries. In our work, hierarchical NiCo2Se4 nanoneedles/nanosheets are deposited on the skeleton of N-doped three dimensional porous graphene (NPG) by a convenient solvothermal method and subsequent gas-phase selenization process. Compared with NiCo2Se4 powder, the optimized NiCo2Se4/N-doped porous graphene composite (denoted as NCS@NPG) as self-supporting anode exhibits the excellent electrode activity for SIBs, with a specific capacity of 500 mAh/g and 257 mAh/g at a current density of 0.2 A/g and 6.4 A/g, respectively. The high specific capacity as well as rate capacity can be attributed to the three-dimensional graphene skeleton with high electrical conductivity and pore structure, which provides convenient ion and electron transmission channels.

1T/2H Mixed Phase MoS2 Nanosheets Integrated by a 3D Nitrogen-Doped Graphene Derivative for Enhanced Electrocatalytic Hydrogen Evolution.

Molybdenum disulfide (MoS2) has become one of the most promising non-platinum-based electrocatalysts for the hydrogen evolution reaction (HER) because of its unique layered structure. However, the catalytic performance of the thermodynamically stable MoS2 is hindered by its poor conductivity and scarce active sites. We developed a 3D porous N-doped graphene derivative-integrated metal-semiconductor (1T-2H) mixed phase MoS2 (MNG) using urea as a doping reagent. The highly exposed active sites were achieved by inducing the phase transition of MoS2 from 2H phase to 1T phase and the inclusion of highly N-incorporated reduced graphene oxide, both of which were simultaneously realized by optimizing the concentration of the doping reagent. Moreover, the charge/proton transfer was enhanced by the well-designed porous architecture and hydrophilic 1T-MoS2. With these advantages, the optimized MNG-40 catalyst has a small overpotential of 157 mV at a cathodic current density of 10 mA cm-2, a relatively low Tafel slope of 45.8 mV dec-1, and an excellent stability. This work represents a new strategy to design higher-performance HER catalysts and provides new insights into the structural regulation of metal composite transitions.

Synthesis of Ultrasmall, Homogeneously Distributed Ni3Fe Alloy Nanoparticles on N-Doped Porous Graphene as a Bifunctional Electrocatalyst for Rechargeable Flexible Solid Zinc-Air Batteries

Rechargeable solid-state Zn-air batteries (ZABs) have drawn attractive prospects for flexible wearable electronic devices; however, their practical application is severely hindered due to the slugg...

Hierarchical porous N-doped graphene aerogel with good wettability for high-performance ionic liquid-based supercapacitors

The improvement of the wettability between electrode materials and ionic liquid electrolytes is critical to increase the performance of electrode materials for supercapacitors. Herein, we demonstrate the synthesis of a urea phosphate-derived graphene aerogel (UPGA) with good wettability by one-step hydrothermal treatment using graphene oxide (GO) as the precursor and urea phosphate (UP) as both the nitrogen dopant and hydroxyl group protector. The as-obtained UPGA has appropriate doped-N atoms, unique hierarchical porous structure, and good wettability by 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4) ionic liquid. The UPGA displays a high specific capacitance of 196.7 F g−1 at 1 A g−1. Moreover, a symmetrical UPGA-based supercapacitor delivers an excellent energy density of 97.2 Wh kg−1 at a power density of 0.9 kW kg−1 and a good cycling stability with the capacitance retention of 78.3% after 5500 cycles at 1 A g−1. Therefore, the UPGA exhibits great potential in supercapacitor as electrode material.

One-pot electrochemical assembling of porous cobalt hydroxide/nitrogen-doped porous graphene onto Ni foam as a binder-free electrode for supercapacitor applications

• N-doped porous graphene was synthesized through catalytic-assisted chemical vapor deposition method. • The binder-free Co(OH) 2 @N-doped graphene/Ni foam was prepared through one-pot deposition strategy. • Specific capacitances as high as 1907 f g –1 and cycling retention of 95.9% after 4000 consecutive cycles at 2 a g − 1 . • Full synergetic contribution between EDL and pseudocapacitive based charge storing behaviors was observed. In this paper, cobalt hydroxide nanoplates/nitrogen-doped porous graphene (Co(OH) 2 @NPG) nanocomposite were deposited onto Ni foam through a facile co-electrodeposition route, and the charge storage capability of the fabricated Co(OH) 2 @NPG/NF was evaluated as a binder-free supercapacitor electrode. The co-deposition of cobalt hydroxide/N-doped porous graphene was carried out, for the first time, from a NPG dispersed aqueous electrolyte containing 5 mM cobalt nitrate. The characterization techniques of XRD, IR, FE-SEM, BET, Raman and TG proved uniform deposition of hexagonal β-Co(OH) 2 nanoplates onto N-doped porous graphene electrophoretically deposited onto Ni foam surface. Raman spectroscopy results confirmed the charge transfer between NPG and cobalt hydroxide through red shift in comparison to single analogous material. The prepared composite powder exhibited enhanced surface area as compared with pristine hydroxide powder (285.716 m²/g vs. 185.2 m²/g), where composite material showed mesoporous texture with IV hysteresis loop isotherm. Furthermore, the Co(OH) 2 /NPG electrode exhibited specific capacity of 1144 C g − 1 and cycling retention of 95.9% after 4000 consecutive cycles at 2 A g − 1 as well as 86.8% after 4000 consecutive cycles at 8 A g − 1 whereas the single analogous cobalt hydroxide deposited onto Ni foam showed specific capacity of 798 C g –1 and capacity stabilities of 83.4% and 60.1% after 4000 cycles at 2 and 8 A g − 1 . The improved electrochemical performance in comparison to Co(OH) 2 /NPG nanocomposite electrode was ascribed to the full accessibility of Co(OH) 2 active material over large surface area of N-doped graphene for fast charge transportation and synergetic contribution between electric double layer and pseudocapacitive based charge storing in composite form.

Binder-free high-performance Fe3O4 fine particles in situ grown onto N-doped porous graphene layers co-embedded into porous substrate as supercapacitor electrode

It has repeatedly been reported that low conductivity of iron oxide as a major challenge limited its supercapacitive application, where compositing Fe3O4 with carbonaceous nanomaterial can be considered as excellent solution strategy. In this paper, we report Fe3O4 nanoparticles electrochemically deposited on graphene oxide sheets as high-performance nanocomposite for energy storage applications. Iron oxide nanoparticles (Fe3O4) are cathodically decorated on N-doped porous graphene (N-PG) nanosheets. The prepared pristine and nanocomposite materials were characterized by FT-IR, Raman, XRD, BET, TEM, FE-SEM, EDS, as well as TGA/DSC techniques. The electrochemical properties of resulting Fe3O4/Ni foam and Fe3O4@N-PG/Ni foam electrodes were investigated through CV, GCD, and EIS techniques, and the obtained data showed that the fabricated hybrid electrode (i.e., Fe3O4@N-PG/Ni foam) is enable to present specific capacitance values s as high as 822 and 631 F g−1 at the 0.5 and 10 A g−1, respectively, where the pristine Fe3O4/Ni foam electrode showed 279 and 131 F g−1 at the 0.5 and 10 A g−1. Furthermore, the hybrid Fe3O4@N-PG/Ni foam electrode showed excellent cycling ability, good high rate, and higher energy density as compared with the Fe3O4/Ni foam electrode. These enhancements were assigned to the synergetic contributions between N-doped porous graphene sheets and iron oxide particles, which mainly results from the rational architecture of N-PG nanosheets and Fe3O4 nanoparticles provided by the applied synthetic route.

Binder-free hierarchical porous N-doped graphene directly anchored on carbon fiber cloth for high-performance electrochemical energy storage

Abstract A binder-free hierarchical porous N-doped graphene directly anchored on carbon fiber cloth was manufactured by a simple and practical two-step process, in which polyindole/graphene oxide (PIn/GO) composites were prepared by in-situ oxidation polymerization of indole on the surface of GO, and then PIn/GO composites coated on the surface of carbon fiber cloth was activated with KOH at 700 °C. By adjusting the contents of PIn, GO, and KOH, a hierarchical porous P7G-K-2 electrode with N content (4.98 at.%) was obtained and showed lager specific surface area and low interfacial contact resistance. The electrochemical evaluation showed that the P7G-K-2 electrode had a maximum specific capacitance of 451 F g−1 at 1 A g−1 and excellent rate performance. Moreover, a simple supercapacitor consisting of two symmetrical P7G-K-2 electrodes, P7G-K-2//P7G-K-2, was assembled, the specific energy of 21.8 Wh kg−1 can be obtained at the specific power of 75 W kg−1, and it had excellent long-term cycle stability (maintaining 92% initial specific capacitance after 10,000 cycles). The excellent performance indicates that the P7G-K-2 is a promising candidate for supercapacitor electrode materials with high energy output. And this work provides a strategy to fabricate supercapacitors electrode with high specific power and specific energy.

Synthesis and application of dendritic Pt-Pd bimetallic nanoparticles in imprinted electrochemical sensor for the determination of florfenicol

In this work, the formation mechanism of dendritic Pt-Pd bimetallic nanoparticles (NPs) with perpendicular pore channels in aqueous medium was investigated using hexadecylpyridinium chloride (HDPC) and hexamethylenetriamine (HTM) as structure-directing agents. The results indicated that reaction temperature impacted the properties of the bimetallic components and the particle diameter, while the amount of ascorbic acid (AA) and reaction time impacted the diameter and the amount of HTM determined the pore size. Porous N-doped graphene (N-P-r-GO) was used to load the dendritic Pt-Pd NPs to form a porous and three-dimensional structure on glassy carbon electrode (GCE). As a result, Pt-Pd NPs-N-r-GO / GCE was obtained. Florfenicol (FOL) was imprinted on the modified electrodes using cyclic voltammetry (CV) since indole-5-carboxylic acid was a novel monomer, and FOL functions as a template molecule. The molecularly imprinted polymer (MIP) / Pt-Pd NPs-N-r-GO / GCE was successfully obtained by eluting the template molecule from the polymer, and Fe(CN)63−/4− was used to detect the impedance signal for the recognition of FOL. This sensor exhibited excellent response for FOL in the linear range of 5.0 × 10-8 ∼ 8.0 × 10-6 mol L-1 with detection limit of 1.0 × 10-9 mol L-1. The obtained sensor also exhibited excellent response for FOL detection in real samples.

Sulfur-Rich Molybdenum Sulfide Grown on Porous N-Doped Graphene for Efficient Hydrogen Evolution

MoS2 and its derivates have been regarded as a promising catalyst for the hydrogen evolution reaction (HER), and their edge sulfur sites are key factors for the HER performance. Here, we develop a facile strategy to grow nonstoichiometric molybdenum sulfide (MoSx) with more active sulfur sites on porous N-doped graphene (MoSx@CN). Experiments demonstrate that the introduction of porous N-doped graphene not only facilitates the fast transfer of charge and the efficient infiltration of the electrolyte but the N dopants could be used as the nucleation sites for MoSx to possess more active bridging S22– sites. Consequently, the obtained MoSx@CN catalyst possesses an outstanding HER activity, which shows an overpotential of 256 mV at 100 mA cm–2 with a Tafel slope of 49 mV dec–1. This study provides a new strategy to optimize transition metal dichalcogenide-based catalysts for energy-related applications.

Promoting Effects of Au Submonolayer Shells on Structure-Designed Cu-Pd/Ir Nanospheres: Greatly Enhanced Activity and Durability for Alkaline Ethanol Electro-Oxidation.

Rationally engineering the surface physicochemical properties of nanomaterials can improve their activity and durability for various electrocatalytic and energy conversion applications. Cu-Pd/Ir (CPI) nanospheres (NSs) anchored on N-doped porous graphene (NPG) [(CPI NSs/NPG)] have been recently demonstrated as a promising electrocatalyst for the alkaline ethanol oxidation reaction (EOR); to further enhance their electrocatalytic performance, the NPG-supported CPI NSs are coated with Au submonolayer (SML) shells (SMSs), through which their surface physicochemical properties can be tuned. CPI NSs/NPG is prepared by our previously developed method and possesses the special structures of composition-graded Cu1Pd1 and surface-doped Ir0.03. The Au SMSs with designed surface coverages are formed via an electrochemical technology involving incomplete Cu underpotential deposition (UPD) and Au3+ galvanic replacement. A distinctive volcano-type relation between the EOR electrocatalytic activity and the Au-SMS surface coverage for CPI@AuSML NSs/NPG is revealed, and the optimal CPI@Au1/6ML NSs/NPG greatly surpasses commercial Pd/C and CPI NSs/NPG in electrocatalytic activity and noble metal utilization. More importantly, its electrocatalytic durability in 1 h chronoamperometric and 500-cycle potential cycling degradation tests is also significantly improved. According to detailed physicochemical characterizations, electrochemical analyses, and density functional theory calculations, the promoting effects of the Au SMS for enhancing the EOR electrocatalytic activity and durability of CPI NSs/NPG can be mainly attributed to the greatly weakened carbonaceous intermediate bonding and properly increased surface oxidation potential. This work also proposes a versatile and effective strategy to tune the surface physicochemical properties of metal-based nanomaterials via incomplete UPD and metal-cation galvanic replacement for advancing their electrocatalytic and energy conversion performance.

A highly sensitive nonenzymatic H2O2 sensor based on 3D N-doped porous graphene aerogel decorated with AuPd alloy nanoparticles

3D N-doped porous graphene aerogel (3D NPGA) was facilely prepared through a one-step hydrothermal reduction by mixing graphene oxide (GO) and p-phenylenediamine with ammonia solution, followed by a freeze-drying process. Then, the AuPd alloy nanoparticles were deposited on the 3D NPGA to synthesize AuPd/NPGA by reduction of HAuCl4 and PdCl2 using NaBH4 as a reducing agent. NPGA composite shows a microporous with 3D structure, a large specific surface area and reveals edge plane like-sites/defects and can act as support sites for nanoparticles. The obtained AuPd/NPGA exhibits better catalytic activity towards H2O2 reduction compared with Pd/NPGA, Au/NPGA, and 3D NPGA composites. The improved performance of AuPd/NPGA attributed to the 3D porous structure of NPGA and the synergistic effect between Au and Pd NPs in the AuPd alloy as well as between 3D NPGA and AuPd NPs. In the 0.1 M PBS pH 7 electrolyte, the AuPd/NPGA electrode displays a linear response towards H2O2 reduction in the range of 1–1000 μM, high sensitivity of 12,235 μA mM−1 cm−2, low LOD 0.038 μM (S/N = 3) and quick response time (<1 s). This nonenzymatic H2O2 sensor was also displays satisfying selectivity, good reproducibility, and excellent long-term stability. In addition, the AuPd/NPGA electrode can also be employed for H2O2 detection in human serum samples. These results confirm that the AuPd/NPGA composite would be a promising catalytic material to construct sensors in different fields.

Facile synthesis 2D hierarchical structure of ultrahigh nitrogen-doped porous carbon graphene nanosheets as high-efficiency lithium-ion battery anodes

Ultrahigh N-doped porous carbon graphene nanosheets (NPC@GNS) with two-dimensional (2D) multilayer sandwich framework are elaborately designed from ZIF-8 nanoparticles in situ grown on graphene oxide (GO) with 2-methyimidazole and polyvinyl pyrrolidone added as nitrogen precursor through a facile one-step fast pyrolysis and explored in lithium-ion batteries (LIBs). As the process-enhanced anode material, the NPC@GNS provide a high capacity of 906.6 mAh g−1 after 100 cycles at 0.5 A g−1, and an average capacity of 378.2 mAh g−1 after an extremely long cycling durability over 1000 cycles at 5 A g−1. It is worth noting that the superior electrochemical performance of the NPC@GNS electrode as the anode for LIBs confirms the reliability of the sufficient “point and plane” 2D sandwich framework, and a portion of the micropores and a large number of preferred mesoporous channels help to facilitate rapid charge transfer, which indicates that NPC@GNS is a vibrant material that plays a key role in contributing to the application in future energy storage.

Front Cover: 3D Nitrogen‐Doped Graphene Encapsulated Metallic Nickel–Iron Alloy Nanoparticles for Efficient Bifunctional Oxygen Electrocatalysis (Chem. Eur. J. 18/2020)

Constructing high-efficient, low-cost and robust oxygen electrocatalysts toward rechargeable Zn–air batteries remains a big challenge. Herein, metallic Ni3Fe alloy nanoparticles encapsulated in 3D porous N-doped graphene aerogel was prepared through a facile hydrothermal assembly and calcination process. Inspired by the unique configuration and strong electronic interactions between Ni3Fe and N-doped graphene, Ni3Fe-GA1 exhibited outstanding activity and stability for OER, ORR, and Zn–air batteries. More information can be found in the Full Paper by L. Xu, L. Mai, et al. on page 4044.

In situ fabrication of hierarchical iron oxide spheres@N-doped 3D porous graphene aerogel for superior lithium storage

To improve the electronic conductivity and dramatic volume change of iron oxide as anode for lithium-ion batteries, we finally fabricate a hierarchical aerogel composite of FeOx spheres encapsulated in porous N-doped three-dimensional graphene (FeOx@N-3DG) via a facile in situ electrostatic self-assembly strategy assisted with hydrothermal. In the hierarchical architecture, the distributed FeOx spheres that consist of Fe2O3 and Fe3O4 crystals are intimately wrapped by N-3DG acting as protective elastomer to buffer the volume change during cycling. Moreover, the integrally interconnected porous structure is beneficial for fast electron transfer and penetration of the electrolyte. More importantly, the abundant grain boundaries of Fe2O3 and Fe3O4 crystals inside FeOx spheres provide smooth channels for fast lithium-ion transport and increase lithium storage sites. Therefore, FeOx@N-3DG anode material exhibits high specific capacity (1100 mAh g−1 after 200 cycles at 0.5 A g−1), excellent rate performance (550 mAh g−1 at 5 A g−1) and outstanding long cycling stability (81.6% of capacity retention after 1000 cycles at 1 A g−1), which is attributed to the superior surface capacitance behavior in the hierarchical architecture during charging and discharging. Thus, the hierarchical FeOx@N-3DG aerogel has potential to be an advanced anode material for lithium-ion batteries.