Non-precious Metal-based Electrocatalysts Research Articles

MOFs as Versatile Catalysts: Synthesis Strategies and Applications in Value-Added Compound Production.

Catalysts played a crucial role in advancing modern human civilization, from ancient times to the industrial revolution. Due to high cost and limited availability of traditional catalysts, there is a need to develop cost-effective, high-activity, and nonprecious metal-based electrocatalysts. Metal-organic frameworks (MOFs) have emerged as an ideal candidate for heterogeneous catalysis due to their physicochemical properties, hybrid inorganic/organic structures, uncoordinated metal sites, and accessible organic sections. MOFs are high nanoporous crystalline materials that can be used as catalysts to facilitate polymerization reactions. Their chemical and structural diversity make them effective for various reactions compared to traditional catalysts. MOFs have been applied in gas storage and separation, ion-exchange, drug delivery, luminescence, sensing, nanofilters, water purification, and catalysis. The review focuses on MOF-enabled heterogeneous catalysis for value-added compound production, including alcohol oxidation, olefin oligomerization, and polymerization reactions. MOFs offer tunable porosity, high spatial density, and single-crystal XRD control over catalyst properties. In this review, MOFs were focused on reactions of CO2 fixation, CO2 reduction, and photoelectrochemical water splitting. Overall, MOFs have great potential as versatile catalysts for diverse applications in the future.

Niobium-doped conductive TiO-TiO2 heterostructure supported bifunctional catalyst for efficient and stable zinc-air batteries

The development of highly active and durable nonprecious metal-based bifunctional electrocatalysts for oxygen reduction/evolution reaction (ORR/OER) is important for rechargeable zinc-air batteries. Herein, a three-dimensional conductive niobium-doped TiO-TiO2 heterostructure supported ZIF-67-derived Co-NC bifunctional catalyst was fabricated. In the Co-NC@Nb-TiOx catalyst, the Nb doping promoted the formation of TiO-TiO2 heterojunction support, enhanced its conductivity and stability and provided strong electron metal-support interaction between Co-NC and Nb-TiOx. Also, the supported Co-NC nanoparticles provided abundant active sites with excellent ORR/OER activity. Experimental analysis reveals that the high OER activity of Co-NC@Nb-TiOx can be attributed to the in-situ generated CoOOH species. It exhibits excellent ORR activity, as shown by its onset potential (0.95 V vs. RHE) and half-wave potential (0.86 V vs. RHE). Its OER overpotential at 10 mA cm−2 is 480 mV. The zinc-air battery realizes outstanding cycling stability over 225 h cycles tested at 10 mA cm−2. This work demonstrates the importance of designing highly stable metal oxide-supported catalysts in electrochemical energy conversion devices.

Mo-doped Ni3S4 nanosheets grown on carbonized wood as highly efficient and durable electrocatalysts for water splitting

Rational design and fabrication of nonprecious metal-based electrocatalysts with high activity and excellent stability for overall water splitting (OWS) is still a grand challenge. Here we report a novel electrocatalyst constructed by incorporating molybdenum into the Ni3S4 lattices grown on carbonized wood (denoted as Mo-Ni3S4/CW). Experimental results and density functional theory (DFT)-based calculations demonstrate that lattice expansion of Ni3S4 caused by Mo doping optimizes adsorption energy of hydrogen/oxygen species and regulates local charge density of active sites, which promote the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Also, a nickel (oxy)hydroxide (Ni-OOH) layer generated via surface reconstruction of Ni3S4 nanosheets improves the intrinsic activity for OER. Moreover, the 3D low-tortuosity porous CW substrate increases the exposure of active specific surface, accelerates the rates of electron transfer, electrolyte diffusion, and gas products escaping. Accordingly, an optimized electrocatalyst (Mo-Ni3S4/CW-0.4) exhibits ultralow overpotentials of 17 and 240 mV for HER and OER at 10 mA cm−2, respectively. Besides, an electrolyzer composed of Mo-Ni3S4/CW-0.4 electrodes as both the anode and cathode shows a low cell voltage of 1.46 V at 10 mA cm−2 while maintaining superior durability over 50 h for OWS. Further, it requires only 0.19 V to achieve 10 mA cm−2 for hydrazine oxidation-assisted water electrolysis, indicating highly attractive potential for economical hydrogen production coupling with pollutants treatment.

Facile eggplant assisted mixed metal oxide nanostructures: A promising electrocatalyst for water oxidation in alkaline media

In terms of efficiency and availability for electrochemical water splitting (EWS), producing electrocatalytic material for hydrogen (H2) fuel remains a difficulty. Furthermore, developing and producing low-cost, non-precious metal-based electrocatalysts for practical use is a global priority for researchers. Significant overpotential, low conductivity, and increased density are still factors to consider for alkaline water oxidation. We present here coprecipitated alumina (Al2O3) and eggplant-based cobalt oxide (Co3O4) nanostructures as electrocatalysts for the oxygen evolution reaction (OER). The as-prepared electrocatalyst offers active sites, enhanced electrical conductivity, and durability in the direction of OER. The desired electrocatalyst show lower overpotential value of 245 mV vs. a reversible hydrogen electrode (RHE) at a current density of 20 mA/cm2, a Tafel slope of 64 mV/dec, and stable electrochemical performance for 45 h as a result of a longer electrochemical activity. These findings suggest that this mixed metal oxide (nanostructures)-based electrocatalyst is a viable, active, and stable element for use in energy storage and conversion applications.

Facilitating Reconstruction of the Heterointerface Electronic Structure by the Enriched Oxygen Vacancy for the Oxygen Evolution Reaction

Exploring high-performance non-precious metal-based electrocatalysts for the sluggish oxygen evolution reaction (OER) process is fundamentally significant for the development of multifarious renewable energy conversion and storage systems. Oxygen vacancy (Vo) engineering is an effective leverage to boost the intrinsic activity of OER, but the underlying catalytic mechanism remains anfractuous. Herein, we realize the construction of oxygen vacancy-enriched porous NiO/ln2O3 nanofibers (designated as Vo-NiO/ln2O3@NFs hereafter) via a facile fabrication strategy for efficient oxygen evolution electrocatalysis. Theoretical calculations and experimental results uncover that, compared with the no-plasma engraving component, the presence of abundant oxygen vacancies in the Vo-NiO/ln2O3@NFs is conducive to modulating the electronic configuration of the catalyst, altering the adsorption of intermediates to reduce the OER overpotential and promote O* formation, upshifting the d band center of metal centers near the Fermi level (Ef), and also increasing the electrical conductivity and enhancing the OER reaction kinetics simultaneously. In situ Raman spectra proclaim that the oxygen vacancy can render the NiO/ln2O3 more easily reconstructible on the surface during the OER course. Therefore, the as-obtained Vo-NiO/ln2O3@NFs demonstrated distinguished OER activity, with an overpotential of only 230 mV at 10 mA cm-2 and excellent stability in alkaline medium, surmounting the majority of the previously reported representative non-noble metal-based candidates. The fundamental insights gained from this work can pave a new path for the electronic structure modulation of efficient, inexpensive OER catalysts via Vo engineering.

A simple postsynthetic in-situ cation exchange strategy to construct Fe-doped Ni3Se4 nanoarray for enhanced oxygen evolution reaction

For industrial high-purity green hydrogen production, it is necessary to develop efficient, economical and stable non-precious metal-based alkaline media oxygen evolution reaction (OER) electrocatalysts. In this study, a simple stepwise synthesis strategy was proposed to construct a hierarchical MOF-based Prussian blue analogue by Ni-BPDC and derived from it to grow Fe-doped Ni3Se4 in situ on nickel foam (Fe-Ni3Se4/NF) as an efficient and stable alkaline OER electrocatalyst. Fe doping enables better modulation of the electronic structure of Ni3Se4 and increases the number of active sites and electrochemical surface area to improve the OER activity. Fe-Ni3Se4/NF exhibits remarkable electrocatalytic performance in 1 M KOH with low overpotential (211 mV at 10 mA cm−2) and small Tafel slope (34.44 mV dec−1), which is superior to that of commercial RuO2 catalysts. Its electrochemical characteristics are stable at 10 mA cm−2 for more than 24 h, making it a viable non-precious metal-based electrocatalyst for alkaline OER. This synthetic approach could open up new possibilities for the fabrication of MOF-based hierarchical Prussian blue analogs as well as derivatives to be oriented for applications in various fields.

Catalytic upcycling of waste polypropylene for gram-scale production of FeCo@N-doped carbon nanotubes toward efficient oxygen reduction electrocatalysis

Exploring novel low-cost and high-efficiency non-precious metal catalysts for use in oxygen reduction reactions (ORR) is of key importance. Based on catalytic pyrolysis of waste plastics, a facile method for preparing N-doped Fe/Co-encapsulated carbon nanotubes (FexCoy@NCNTs) was proposed. Particularly, gram-scale yield of the composite catalyst (3.87 g) was achieved in one pot with considerable atomic conversion rate of carbon (∼57.3 %) from waste polypropylene to high-quality CNTs, suggesting great potential for waste plastics valorization. The effects of Fe-to-Co ratios were studied by testing the ORR performance of each sample, indicating that as the Fe proportion increased, the ORR performance initially increased and then decreased. The Fe1Co1@NCNTs catalyst showed optimal performance which was comparable with commercial Pt/C catalyst: Particularly, an initial potential of 0.97 V vs RHE, a half-wave potential of 0.81 V vs RHE, and a limiting current density of –5.68 mA cm−2 were recorded. The encapsulated Fe and Co species in N-doped CNTs enhanced catalytic activity, while the porous carbon structure augmented the exposure of active sites. This strategy offers an auspicious platform for reusing waste plastics in the mass production of CNTs, and also provides an innovative approach for preparing low-cost, high-performance, and non-precious metal-based electrocatalysts for ORRs.

Phosphorus-Doped directly interconnected networks of amorphous Metal-Organic framework nanowires for efficient methanol oxidation

Developing high-performance and low-cost electrocatalysts toward methanol oxidation reaction (MOR) is essential for fuel cell applications. Herein, we report a defect engineering strategy integrating amorphization and phosphorization to construct directly interconnected networks of amorphous NiCo-based metal–organic framework nanowires (a-NiCo-MOFNWs) with phosphorus (P) doping. The resulting P-doped a-NiCo-MOFNWs (a-NiCo-MOFNWs-P) network displays superior MOR efficiency and long-term durability over 1000 cyclic voltammetry (CV) measurements. The special structure of directly interconnected networks and the synergistic effect between the amorphous MOFs and dispersed phosphorus species give rise to abundant exposed active sites, accelerated electron transport, and increased porosity for mass transfer, thus boosting the reaction kinetics of MOR. This work provides additional insights into the network assembly and structural evolution of one-dimensional (1D) MOFs, and also opens up new avenues for the design of highly reactive and robust non-precious metal-based electrocatalysts.

N-doping carbon-coated Cu@C(N) nanocapsules synthesized by arc plasma toward high-performance ORR electrocatalyst

The development of efficient and cost-effective methods for the synthesis of non-precious metal as the catalytic material for oxygen reduction reaction (ORR) is addressing a key barrier to fuel cell deployment in a wide range of applications. In this study, core-shell carbon-coated copper nanoparticles (Cu@C) were prepared using arc discharge plasma under argon and hydrogen atmospheres. And nitrogen doping was achieved during the subsequent heat treatment using dicyandiamide as the nitrogen source. The results showed that the catalysts had better ORR catalytic activity, better stability and better methanol tolerance than Pt/C, and the ORR reaction process was nearly four-electron pathway. The successful doping of nitrogen increased the reaction sites. And the addition of copper core improved the conductivity of the catalytic material. Meanwhile, the N-C shell layer protected the Cu nanoparticles from dissolving in aqueous solutions or being chemically oxidized, facilitating the electronic interaction of the core Cu nanoparticles with the N-C shell layer. This study provides an insight into the preparation of high-efficiency non-precious metal-based ORR electrocatalysts by DC arc plasma, a beneficial method.

PO6 geometric configuration unit enhanced electrocatalytic performance of Co3O4 in acidic oxygen evolution

It is challenging to develop high-efficient and stable nonprecious metal-based electrocatalyst for oxygen evolution reaction (OER) in acid for proton exchange membrane (PEM) water splitting. Herein, P atoms were introduced into the lattice of spinel Co3O4 (P-Co3O4) to replace with octahedral coordinated Co3+ via a hydrothermal process following a thermal treatment. The formation of PO6 geometric configuration unit in Co3O4 can trigger electron rearrangement around Co ions, which resulted in the high-active Co2+ site on the surface, significantly decreasing the energy barrier of rate-determining step for OER. Moreover, the weaker covalency of the Co 3d-O 2p bond and higher formation energy of oxygen vacancy around Co2+ in P-Co3O4 inhibited the participation of lattice oxygen during OER process, enabling that P-Co3O4 can work stably in acidic media. The obtained P-Co3O4 afforded satisfying stability over 30 h in a PEM electrolysis device with an overpotential of 400 mV@10 mA/cm2 in 0.1 M HClO4.

Electrocatalytic activity of Cu MOF and its g-C3N4-based composites for oxygen reduction and evolution reaction in metal-air batteries

For metal air batteries the synthesis of highly efficient, sustainable, non-precious metal-based electrocatalysts with bifunctional catalytic activity for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) are essential. In this work via simple hydrothermal method Cu MOF and its g-C3N4 based composites are prepared and characterized via FTIR, XRD, SEM and EDX. The Cu MOF and the g-C3N4-based electrode can work synergistically to enhance the electrochemical process. The Cu MOF accepts electrons, and the g-C3N4-based electrode donates them. Consequently, improving electron transport between the electrode and oxygen molecule accelerates reaction kinetics. Further, via incorporating g-C3N4 in Cu MOF makes the charge transfer between the electrode and electrolyte effective, making it a viable option for electrochemical devices. In stable states, Cu MOF with 5 wt% of graphitic carbon nitride has a low overpotential (389 mV/10 mA/cm2), a Tafel slope of 26.12 mV/dec, and high stability over 3600 s in 1 M KOH. EIS result showed that g-C3N4 decreases charge transfer resistance by allowing electroactive species to contact the catalyst. Further, via three-electrode setup under nitrogen and oxygen conditions at different scan speeds ORR analysis is done. The composite Cu MOF (5 wt%) exhibits the maximum current density of 1.31 mA/cm2 at 0.05 mV /s scan rate in 1 M KOH, surpassing the original Cu MOF, which produced 1.09 mA/cm2.

Completely reconfigured Fe1-xS/C ultra-thin nanocomposite lamellar structure for highly efficient oxygen evolution

The surface reconfiguration of electrocatalysts during oxygen evolution reaction (OER) is much more important to reveal the actual catalytic active species, thus realizing the optimization of electrocatalyst activity. Herein, we demonstrate a simple strategy to achieve the complete electrochemical reconfiguration of Fe1-xS nanocrystals/ultra-thin carbon (Fe1-xS NCs/@ UT-C) nano-lamellar structure during the OER process. The uniform dispersion of Fe1-xS nanocrystals on the ultra-thin carbon layer favors the rapid complete reconfiguration. Such rapid reconfiguration creates new actual catalytic active species of amorphous iron-based oxide transformed from Fe1-xS, which is coupled with an ultra-thin carbon layer to facilitate the charge transfer of OER. More detailed, partly graphitization of the ultra-thin carbon layer not only affords to overcome the ohmic losses but also enhances the overall electrical conductivity and OER activity of the material. The Fe1-xS NCs/@UT-C as pre-catalyst shows high OER activity with a low overpotential of only 303 mV at 100 mA cm−2 and a Tafel slope of 55 mV/dec. In addition, the reconfigured catalyst has good stability for 168 h in alkaline conditions. This work is beneficial to understand the reconfiguration of electrocatalysts and design high-efficiency nonprecious metal-based electrocatalysts.

Iron-Cobalt-Cerium Multimetallic Oxides Derived from Prussian Blue Precursors: Enhanced Oxygen Evolution Electrocatalysis.

Exploring non-precious metal-based electrocatalysts is still challenging in 21st century. In this work, a series of hexagonal bipyramidal Ce-based PBA materials as precursors with different Fe/Co metal ratios, namely as CeFex Co1-x -PBA, are successfully constructed via co-precipitation method and converted into corresponding metal oxides (denoted as Fex Co1-x CeOy ) via thermal treatment. Then, they as electrocatalysts realize highly efficient oxygen evolution reaction (OER). Especially, as-synthesized Fe0.7 Co0.3 CeOy electrocatalyst shows very low overpotentials of 320 mV at the current density of 10 mA cm-2 and the Tafel slop of 98.4 mV dec-1 in 1 M KOH with remarkable durability for 24 h, which was due to the synergistic effect of multi-metal FeCoCe centers. Furthermore, a two-electrode cell of Fe0.7 Co0.3 CeOy /NF||Pt/C/NF realizes outstanding overall water splitting with a voltage of only 1.71 V at 10 mA cm-2 and remarkable long-term durability, that is even superior to benchmark IrO2 /NF||Pt/C/NF counterpart.

Interface engineering of porous nickel-iron phosphates with enriched oxygen vacancies as an efficient bifunctional electrocatalyst for high current water splitting

The delicate design of non-precious metal-based bifunctional electrocatalysts for simultaneous oxygen/hydrogen evolution reactions is pivotal for developing green and sustainable energy sources. Here, we have fabricated a novel nickel-iron phosphate heterostructure with abundant oxygen vacancies (Fe0.86Ni0.14-POx/CC) via hydrothermal reaction and gas-phase phosphating treatment. By appropriately adjusting the ratio of Ni/Fe, the electronic structure is regulated, thereby optimizing the oxygen vacancies to form abounded electrocatalytic active centers on the catalyst surface. The obtained Fe0.86Ni0.14-POx/CC catalyst reveals low overpotentials of 247 and 125 mV for OER and HER at a current density of 10 mA cm−2, respectively. Besides, the overall water splitting electrolyzer originated from Fe0.86Ni0.14-POx/CC only requires a cell voltage of 2.01 V to deliver a current density of 500 mA cm–2 with good stability of 100 h (10 mA cm−2). Importantly, Fe0.86Ni0.14-POx/CC possess 96.9 and 97.7% Faradaic yield for the generation of H2 and O2, respectively. This work invokes new feasibility for developing robust and cost-effective phosphate catalysts for electrochemical overall water splitting.

Thin Films Fabricated by Pulsed Laser Deposition for Electrocatalysis

Thin Films Fabricated by Pulsed Laser Deposition for Electrocatalysis

N,S co-doped porous carbon with Co9S8 prepared with a Co-FF-derived Co3O4 template: a bi-functional electrocatalyst for rechargeable zinc-air batteries.

To achieve broad commercialization of rechargeable metal-air batteries, the development of non-precious metal-based bi-functional oxygen electrocatalysts is critical. In this study, we prepared N,S co-doped porous carbon materials containing Co9S8 nanoparticles (Co9S8/NSC) through a one-step pyrolysis process. The process involved the pyrolysis of a polydopamine (PDA) coated Co-formic acid framework (Co-FF) derived Co3O4 and thiourea. The improved catalyst Co9S8/NSC-1 exhibited satisfactory long-term durability and superior oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activity, the half-wave potential (E1/2) of the ORR reached 0.83 V, and the OER overpotential at 10 mA cm-2 (η10) was 300 mV. The zinc-air battery (ZAB) based on Co9S8/NSC-1 assembly had a maximum power density of 102.0 mW cm-2 and the cycle life reached 500 cycles. The material preparation method was simple, environmentally friendly and inexpensive, providing a feasible strategy for the development of non-precious metal-based electrocatalysts.

Hydrogen production by traditional and novel alkaline water electrolysis on nickel or iron based electrocatalysts.

Hydrogen production through alkaline water electrolysis holds great promise as a scalable solution for renewable energy storage and conversion. The development of non-precious metal-based electrocatalysts with low-overpotential for alkaline water electrolysis is essential to decrease the cost of electrolysis devices. Although the Ni-based and Fe-based electrocatalysts have been commercially employed in the cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER), it is imperative to persistently pursue the advancement of highly efficient electrocatalysts with enhanced current density and fast kinetics. This feature article overviews the progress of NiMo HER cathodes and NiFe OER anodes in the traditional alkaline water electrolysis process for hydrogen production, including the detailed mechanisms, preparation strategies, and structure-function relationship. Moreover, recent advances of Ni-based and Fe-based electrodes in the process of novel alkaline water electrolysis, involving small energetic molecule electro-oxidation and redox mediator decoupled water electrolysis, are also discussed for hydrogen production with low cell voltage. Finally, the perspective of these Ni-based and Fe-based electrodes in the mentioned electrolysis processes is proposed.

Electrocatalytic study of the hydrogen evolution reaction on MoS2/BP and MoSSe/BP in acidic media.

Molecular hydrogen (H2) production by the electrochemical hydrogen evolution reaction (HER) is being actively explored for non-precious metal-based electrocatalysts that are earth-abundant and low cost like MoS2. Although it is acid-stable, its applicability is limited by catalytically inactive basal planes, poor electrical transport and inefficient charge transfer at the interface. Therefore, the present work examines its bilayer van der Waals heterostructure (vdW HTS). The second constituent monolayer boron phosphide (BP) is advantageous as an electrode material owing to its chemical stability in both oxygen and water environments. Here, we have performed first-principles based calculations under the framework of density functional theory (DFT) for the HER in an electrochemical double layer model with the BP monolayer, MoS2/BP and MoSSe/BP vdW HTSs. The climbing image nudged elastic band method (CI-NEB) has been employed to determine the minimum energy pathways for Tafel and Heyrovsky reactions. The calculations reveal that the Tafel reaction shows no reaction barrier. Thereafter, for the Heyrovsky reaction, we obtained a low reaction barrier in the vdW HTSs as compared to that in the BP monolayer. Subsequently, we have observed no significant difference in the reaction profile of MoS2/BP and MoSSe/BP vdW HTSs in the case of 2 × 2 supercell configuration. However, in the case of 3 × 3 and 4 × 4 configurations, MoSSe/BP shows a feasible Heyrovsky reaction with no reaction barrier. The coverages with 1/4H+ concentration (conc.) deduced high coverage with low conc. and low coverage with high conc. to be apt for the HER via the Heyrovsky reaction path. Finally, on observing the activation barrier of the Heyrovsky pathway along with that of second H adsorption at the surface, the Heyrovsky path is expected to be favoured.

Fabrication of Ultra-Durable and Flexible NiPx -Based Electrode toward High-Efficient Alkaline Seawater Splitting at Industrial Grade Current Density.

Designing nonprecious metal-based electrocatalysts to yield sustainable hydrogen energy by large-scale seawater electrolysis is challenging to global emissions of carbon neutrality and carbon peaking. Herein, a series of highly efficient, economical, and robust Ni-P-based nanoballs grown on the flexible and anti-corrosive hydrophobic asbestos (NiPx @HA) is synthesized by electroless plating at 25°C toward alkaline simulated seawater splitting. On the basis of the strong chemical attachment between 2D layered substrate and nickel-rich components, robust hexagonal Ni5 P4 crystalline modification, and fast electron transfer capability, the overpotentials during hydrogen/oxygen evolution reaction (HER/OER) are 208 and 392mV at 200mA cm-2 , and the chronopotentiometric measurement at 500mA cm-2 lasts for over 40 days. Additionally, the versatile strategy is broadly profitable for industrial applications and enables multi-elemental doping (iron/cobalt/molybdenum/boron/tungsten), flexible substrate employment (nickel foam/filter paper/hydrophilic cloth), and scalable synthesis (22 cm × 22cm). Density functional theory (DFT) also reveals that the optimized performance is due to the fundamental effect of incorporating O-source into Ni5 P4 . Therefore, this work exhibits a complementary strategy in the construction of NiPx -based electrodes and offers bright opportunities to produce scalable hydrogen effectively and stably in alkaline corrosive electrolytes.

Preparation of Spiral Nitrogen-Doped Macroscopic Graphene Tube and Tuning the Activity of Oxygen Catalysis by Twisted Ferrum (Fe) Wires

A FeNx-C-based catalyst is considered one of the most promising candidates for the highest oxygen reduction reaction (ORR) activities among nonprecious metal-based electrocatalysts. In this work, a unique catalyst of nitrogen-doped twisted macroscopic graphene tubes decorated with Fe-Nx and bamboo-like carbon nanotubes (CNT) was prepared by using twisted iron wire as a template and cyanamide as a carbon source. The microstructure and physicochemical natures of the samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopic (XPS), X-ray diffraction (XRD), and nitrogen adsorption/desorption measurements. Torsion can promote the dislocation of the iron wire lattice, and activate the surface Fe atoms, thus leading to the growth of bamboo-like carbon nanotubes and forming iron nitride. The product has a graphene-like macroscopic tube structure and exhibits excellent ORR activity. Such excellent ORR performance may be ascribed to the synergistic effect, including high ORR catalytic sites caused by the dislocation of the iron wire lattice, nitrogen heteroatoms doping, favorable reactant transport channels provided by macroscopic tube structure, and fast electron transfer rate induced by 3D continuous networks.