Search

Building on the concept of a thermoelectrocatalyst (TECatal), we propose a simple yet efficient TECatal material, vacancy defect engineered SrTiO3, for stable H2O2 production under temperature gradients. A solid-phase reaction was applied to introduce oxygen vacancies, generating free electrons and inducing a thermoelectric response in SrTiO3. This approach achieved an impressive H2O2 production rate of approximately 764 μmol L−1 g−1 h−1 at a temperature gradient of 130 °C conceiving the feasibility of the thermoelectrocatalyst for harvesting low-grade waste heat. [ABSTRACT FROM AUTHOR]

Adherent bubbles at electrodes are generally treated as reaction penalties. Herein, in situ hydroxylation of indium tin oxide surfaces can be easily achieved by applying a constant potential of +1.0 V in the presence of bubbles. Its successful hydroxylation is further demonstrated by preparing a ferrocene-terminated film, which is confirmed by cyclic voltammetry and X-ray photoelectron spectroscopy. [ABSTRACT FROM AUTHOR]

Sulfide compounds offer promising alternatives for electrocatalysts in water splitting, thanks to their diverse nature, intrinsic activities, affordability, and abundance in the Earth's crust. However, the limited active sites, hindered substance transport, larger particle size, and structural collapse restrict their performance in the electrolysis of water. In order to achieve a dual-functional catalyst with multiple catalytic sites, it is often necessary to construct heterogeneous or composite structures. However, this typically leads to an increase in catalyst resistance and also affects its operational stability. In response, we successfully prepared a high-entropy sulfide (ZnCoMnFeAlMg)9S8 through a low-temperature solvothermal method. This approach resulted in a reduction in grain size and a doubling of the specific surface area. The high entropy not only maintains the stability of the structure but also induces electron interactions within the catalyst through the interactions of multiple metals. This exposure of more active sites enables the realization of a dual-functional catalyst with multiple catalytic sites within a single structure. In addition, the increased presence of high-valence Fe and Ni ions promotes the chemisorption of intermediates, facilitating electron transfer during the reaction process. Benefiting from this multi-scale regulation strategy, the (ZnCoMnFeAlMg)9S8 displays an ultralow overpotential of 1.39 V at 10 mA cm−2 and a small Tafel slope of 35.3 mV dec−1. Density functional theory calculations indicate that high entropy can significantly modulate the local charge distribution and electronic properties of sulfides, thereby achieving optimal adsorption energy and reducing the potential energy barrier for hydrolysis. This study introduces a fresh approach to the functionalization of high entropy nanomaterials, while simultaneously enhancing the performance of water splitting catalysts. [ABSTRACT FROM AUTHOR]

An anti-solvent slurry method for cocrystal formation is developed and tested in 25 carbamazepine cocrystal systems. With a low solvent/anti-solvent volume ratio, it reduces solubility of reactants and products, and levels out solubility difference of reactants, and consequently generates cocrystals with a higher success rate, higher purity and higher yield than commonly used slurry methods. [ABSTRACT FROM AUTHOR]

In this work, novel high-entropy layered double hydroxide (HELDH) microspheres consisting of nanosheets were synthesized via a simple hydrothermal method through utilizing the combination of low-cost active transition metal elements such as Ni, Fe, Mn, Zn, and Co, as well as non-active Mg and Al elements for electrocatalysis. The reported flower-like seven-element HELDH microspheres self-supported on a nickel foam substrate outperformed the hydroxide analogues with a similar structure in the electrocatalytic oxygen evolution reaction. Specifically, the optimal sample only requires a low overpotential of 183 mV to obtain a current density of 10 mA cm−2 with a small Tafel slope of 49.21 mV dec−1 (more active than RuO2 electrocatalysts) and has an outstanding cycling stability. Furthermore, in 1.0 mol L−1 KOH solution, the potential shows only a negligible increase (<5%) after a continuous test of 48 h even at a high current density of 250 mA cm−2, suggesting its robust durability and promising potential for practical industrial application as OER catalysts. Thus, the present work provided a new strategy to design and prepare high-performance HEM electrocatalysts. In addition, the theoretically calculated results based on density functional theory with the proposed models completely support our experimental results, which provide a new way to manipulate the catalytic performance of HEM electrocatalysts. [ABSTRACT FROM AUTHOR]

The scale-up syntheses of electrocatalysts with rationally designed functional promoter groups that can directly interact with catalytic-centres are much desired for CO2 electroreduction. Here, we propose an in situ copolymerization method that can be applied for the scale-up syntheses of metalloporphyrin based conjugated porous polymers with directly interacting catalytic centres and promoter groups. The thus-obtained materials possess the characteristics of high porosity, adjustable morphology, abundant catalytic sites and directly interacting promoter groups. In particular, CPP–Cu with ferrocene as the promoter group exhibits a FECH4+C2H4 of 94.0% (FECH4, 75.9%, FEC2H4, 18.1%, −0.9 V), which is much higher than that of Cu-porphyrin, Bz-CPP-Cu and the physical-mixture and represents one of the best electro-catalysts so far. DFT calculations reveal that the directly-interacting ferrocene groups could enhance the electron-cloud density of Cu-porphyrin and possess strong adsorption-ability to OH* to kinetically improve the proton-coupled electron transfer for the preferential CO2-to-CH4 pathway. Noteworthily, the synthesis-strategy is easy to scale-up (∼10 g in a batch-experiment) and the reaction-time can be as little as 10 min under microwave-conditions. [ABSTRACT FROM AUTHOR]

Here, a viologen-functionalized metal–organic framework (MOF), MIL-125-RV2+, was obtained by modification of MIL-125-NH2 with viologen molecules. MIL-125-RV2+, the first viologen-based MOF for photocatalytic CO2RR, exhibited excellent photocatalytic activity and high selectivity for HCOO−. The strategy of using photo-responsive color-changing organics to functionalize the MOF is significant for achieving efficient CO2RR. [ABSTRACT FROM AUTHOR]

Supramolecular isomers can serve as effective model systems to explore the stable self-assembly process of specific structures, but it is often difficult to capture multiple variants in different stable states. Here, four variants (CuL-1, CuL-2, CuL-3, and CuL-4) assembled from the same CuICuIIL-metalloligand motif form different structures in which the dihedral angles of adjacent CuICuIIL-metalloligands (9°, 33°, 84°, 180°) increase gradually. CuL-2, CuL-3 and CuL-4 belong to supramolecular isomers. The relevant experimental and calculative results demonstrate that the larger the dihedral angle of adjacent CuICuIIL-metalloligands, the higher the stability of the structural variant. Moreover, the metastable structures (CuL-1, CuL-2, and CuL-3) can undergo single crystal-to-single crystal transformation into the most stable variant (CuL-4). Additionally, based on the unique mixed-valence copper structure distribution characteristics and strong alkali stability, CuL-4 is applied as an electrocatalyst for CO2 electroreduction (CO2RR), in which CO2 can be reduced to high-value hydrocarbons with a total faradaic efficiency of 85.02% (FECH4 = 67.76%, FEC2H4 = 17.26%) at −1.0 V (j = 477.42 mA cm−2). As far as we know, CuL-4 is better than most crystalline CO2RR catalysts. Furthermore, the corresponding DFT calculation proves that the independent Cu(I) sites are mainly responsible for CH4 generation, while the synergistic two adjacent Cu(II) sites are inclined to produce C2H4. Significantly, crystalline CuL-4 can serve as a well-defined model electrocatalyst to explore the role of evenly distributed mixed-valence copper active sites in reducing CO2 to hydrocarbons. [ABSTRACT FROM AUTHOR]

A series of Li–CO2 battery cathode materials are reported based on metal–organic frameworks with dual-metal sites containing a metalloporphyrin and a metal-coordinated pyrazole. MnTPzP-Mn demonstrates a low voltage hysteresis of 1.05 V at 100 mA g−1 and good stability of 90 cycles at 200 mA g−1. Among them, the Mn-coordinated pyrazole site can promote the effective decomposition of Li2CO3, and the Mn-metalloporphyrin site contributes to the activation of CO2. This is the first example of using a crystalline cathode material with a well-defined structure to reveal natural catalytic sites for CO2 reduction/evolution reactions under aprotic conditions in Li–CO2 batteries. [ABSTRACT FROM AUTHOR]

The catalyst-free oxidative cleavage of (Z)-triaryl-substituted alkenes bearing a pyridyl motif in ambient air under the irradiation of blue LEDs at room temperature has been developed. The reaction was facile and scalable, and proceeded with good functional group tolerance, affording pharmaceutically useful 2-acyl pyridines. The electron paramagnetic resonance (EPR) studies together with control experiments showed that the singlet oxygen (1O2) and superoxide anion (O2˙−) are the reactive oxidants. The 1O2 generation mechanism correlated well with the photophysical properties of the substrate (Z)-triaryl-substituted alkenes, the excited state of which was proved to serve as the triplet sensitizer for the generation of 1O2. [ABSTRACT FROM AUTHOR]

Two isostructural MOFs with coordination of different halogen ions (Cl− and Br−), namely NNU-17 and NNU-18, were utilized to reveal the influence of different electron-withdrawing halogen anions on ECR performance. The performance difference between them mainly originates from the different abilities of adsorption and activation of CO2 by halogen ions. [ABSTRACT FROM AUTHOR]

Piezocatalysis and piezo-photocatalysis have recently emerged as promising strategies to address energy and environmental issues through harvesting mechanical energy. Herein, we report that electrical conductivity, rather than piezoelectric coefficient, is more decisive in determining piezocatalytic and piezopotential enhanced photocatalytic activities. The high electrical conductivity of Bi0.5Na0.5TiO3 leads to superior piezo-photocatalytic catalytic activity compared to other reported piezocatalysts for water splitting (H2 production of 158 μmol g−1 h−1), Cr(VI) reduction (first-order rate constant of 0.045 min−1), and degradation of organic pollutants (first-order rate constant of 0.061 min−1 for RhB) by introducing sunlight and ultrasonic mechanical vibration with a frequency of 20–80 kHz. Furthermore, the mechanical power, vibration frequency, and particle size of the material are important factors to optimize the piezocatalytic and piezo-photocatalytic performance. This work provides a useful guide to design new piezocatalytic or piezo-photocatalytic materials by synergistically considering the electrical conductivity and piezoelectric coefficient. [ABSTRACT FROM AUTHOR]

It is still rare for coordination complexes to achieve CO2 reduction reaction in water. Demonstrated here is the self-assembly and CO2 photoreduction performance of two thermodynamically reversibly converted polyoxo-titanium clusters (PTCs), Ti4-C8A and Ti7-C8A, using calix[8]arene with high molecular degrees of freedom and variable conformations as an organic "functional armor". Because of the rich coordination sites and bridging modes of calix[8]arene, the obvious electron transfer effect generated between the titanium–oxo core and calix[8]arene ligand extended the light absorption of the two PTCs from the traditional ultraviolet to the visible region. Moreover, the hydrophobic benzene groups in calix[8]arene endowed the two clusters with high structural and chemical stability in aqueous solutions with different pH values. On this foundation, these two stable and photosensitive clusters were used as heterogeneous molecular photocatalysts for efficient CO2 reduction in water (with triethanolamine as a sacrificial agent) and they exhibited very high CO2-to-HCOO− conversion activity and selectivity. Most importantly, this is the first report of molecular coordination complexes in water containing a sacrificial agent to perform heterogeneous CO2 reduction reaction. [ABSTRACT FROM AUTHOR]

Microplastics are a worldwide problem that poses a giant threat to organisms in the ecosystem and even to human health. The removal of microplastics is a severe challenge that needs to be solved urgently. Herein, a series of zirconium metal–organic framework-based foam materials with interpenetrated pores, high MOF uniformity and excellent durability have been successfully fabricated and applied in simulated microplastics removal in water or seawater conditions. They can be applied to various types and concentrations of microplastics suspensions. It is worth noting that the best of them, UiO-66-OH@MF-3, can efficiently remove microplastics with an efficiency of up to 95.5 ± 1.2% and can maintain high performance in recycling and large-quantity filtration experiments. Besides, we proposed an automatic filtration system powered by sunlight and accomplished it on the lab-scale. The high performances of these foam materials combined with the new concept of automatic filtration systems might shed some light on the development of novel techniques for microplastics removal. [ABSTRACT FROM AUTHOR]

A hierarchical CoS–nanoparticle/carbon nanofibrous composite composed of CoS nanoparticles conformably anchored on the carbon fibres was fabricated by using a natural cellulose substance (e.g., ordinary laboratory filter paper) as the scaffold as well as the carbon source, and was applied as a high-performance anodic material for lithium-ion batteries. The initial cellulose substance (filter paper) was first carbonized at 450 °C, and then treated by KOH at 800 °C to acquire the activated carbon fibres; thereafter, the CoS nanoparticles were deposited onto the activated carbon fibres through a hydrothermal process. Such a porous three-dimensional network structure of the resultant CoS/carbon nanofibrous material inherited from the original cellulose substance resulted in high lithium ion diffusion coefficient, fast electronic transport and fine pseudo-capacitive effect. The composite with 37.0 wt% of cobalt sulfide displayed a high initial specific capacity of 1137.3 mA h g−1 and a stable reversible capacity of 576.7 mA h g−1 after 200 cycles at a current density of 100 mA g−1. Owing to the high specific surface area and porous structure of the CoS–nanoparticle/carbon nanofibrous composite, it delivered superior electrochemical performance during the lithiation/delithiation progress when used as an anodic material for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

An iodine promoted cascade cycloisomerization of 1-en-6,11-diynes is presented for the easy preparation of tetrahydrobenzo[f]isoquinolines. This developed reaction system is identified as having good functional-group applicability and can be scaled up to gram quantities. In this transformation, two new cyclic frameworks and one carbonyl group are formed with four new bonds constructed. Additionally, the resulting iodo-substituted compounds could be further derived through simple elimination reactions. [ABSTRACT FROM AUTHOR]

Identification of proton-exchange membranes (PEMs) with high proton conductivity and long-term durability is highly important for the development of fuel cells. Herein, an efficient and feasible strategy that features different proton sources and hopping site modifications on the stable UiO-66-NH2 framework for hierarchically improving the proton conductivity is demonstrated. As a result, IM-UiO-66-AS showed the highest superprotonic conductivity of 1.54 × 10−1 S cm−1 (80 °C, 98% RH) and outstanding long-term durability of at least 100 h, which surpass those of all the reported proton-conducting MOF materials without guest loading. Furthermore, the manufactured membrane could maintain a high proton conductivity of 1.19 × 10−2 S cm−1 even with continuous work for at least 40 h under the same conditions, suggesting its great potential for further application in devices. [ABSTRACT FROM AUTHOR]

Coordination polymers (CPs) are emerging crystalline materials, and researchers have promoted their potential applications in various fields owing to their easily designed and tailorable structures, guest-accessible cavities and functional tunability. In this review, we mainly focused on describing the recent achievements of CPs/CP-based composites for ionic/electrical conductivity and provided their future perspectives. The designable and tailorable structures of CPs provide great opportunities to systemically tune their ionic/electrical conductivities, and various strategies have been employed to improve their conductivity. Meanwhile, the relationship between their structure and conductivity may offer some guidance for the design and synthesis of new conductive materials with high conductivity. We proposed major fundamental issues to be addressed in material design and application perspectives. By elaborating the advantages and challenges of CPs in ionic/electrical conductivity, some useful advice is provided in this review to shed some light on their development. [ABSTRACT FROM AUTHOR]

The geometrical structures and electronic properties of anionic, neutral, and cationic B3Si11 clusters were investigated by performing ab initio calculations combined with size-selected anion photoelectron spectroscopy. The experimental photoelectron spectrum of the B3Si11− anion is reasonably reproduced by theoretical simulations of two competing isomers. The global minimum of the B3Si11− anion is formed by the fusion of a B3Si7 bicapped tetragonal antiprism to a B3Si4 pentagonal bipyramid by sharing a B3 triangle, while that of neutral B3Si11 has a B3-endohedral sandwich structure composed of a Si5 five-membered ring and a Si6 six-membered ring, and that of the B3Si11+ cation adopts a Si11 tricapped tetragonal antiprism with three face-capping B atoms. It is interesting that a Si5 five-membered ring and a Si6 six-membered ring are stabilized by three B atoms in B3Si11. The three B atoms tend to bond with each other to form a B3 triangle with stronger B–B bonds than B–Si bonds. Moreover, neutral B3Si11 exhibits σ + π double delocalized bonding patterns. Anionic, neutral, and cationic B3Si11 clusters have multiplicity of structural forms and their low-lying isomers show dynamical fluxionality. The bond lengths, bond orders, MO, constant electronic charge density surfaces, and PDOS analyses showed that the three B atoms in B3Si11 have strong bonding interactions. [ABSTRACT FROM AUTHOR]

Designing an all pH value hydrogen evolution reaction (HER) electrocatalyst with low cost and high activity is urgently needed for future energy storage and conversion systems. Metal–organic frameworks (MOFs) with well-defined pore structures and various metal sources provide feasible platforms for the design of efficient electrocatalysts. However, MOFs as crystalline materials are mostly in crystal or powder form, which would hinder their practical application. Herein, polyoxometalate-based MOFs (POMOFs) were synthesized on carbon cloth (CC) through a facile and general solid-phase hot-pressing method for the first time. The thus-obtained POMOFs/CC can be converted into three phase bimetallic phosphides coated with porous carbon on CC through a phosphidation process, show high electrocatalytic stability over a wide pH range (pH, 0–14) and possess excellent HER performance with low overpotential (e.g., 90.5 mV at 10 mA cm−2 in 1 M KOH). Moreover, the POMOFs/CC derived phosphides present high selectivity for H2 production (nearly 100% faradaic efficiency) and ultra-low charge-transfer resistance (0.96 Ω) in alkaline medium, which hold promise for practical applications. This work provides a powerful strategy for the facile production of fast nucleating MOF-derived electrodes with potential for industrial-scale application in energy storage and conversion. [ABSTRACT FROM AUTHOR]

Motivated by recent experimental developments of graphitic-CN (g-CN) sheets, we investigate the suitability of hydrogen storage on Li decorated g-CN via first-principles calculations. We find that the binding energies of Li atoms are very large, ranging from 2.70 to 4.73 eV, which are significantly higher than the cohesive energy of bulk Li. Lithium atoms therefore tend to form 2D rather than 3D patterns on g-CN, promoting reversible hydrogen adsorption and desorption. Remarkably, the average adsorption energy of H2 molecules falls in the 0.14–0.23 eV range, and the Li decorated CN shows a high theoretical gravimetric density of 10.81 wt%, which is favorable for massive hydrogen storage. Our results suggest that the Li decorated CN could be a promising hydrogen storage material under realistic conditions. [ABSTRACT FROM AUTHOR]

Based on first-principles calculations, we present a systematic investigation of the electronic and magnetic properties of armchair phosphorene nanoribbons (APNRs) functionalized by 3d transition metal (TM) atoms. We found that the central hollow site is the most favorable adsorption site for Mn, Co and Ni, while Fe preferentially occupies the edge hollow site. All of the TM atoms bind to the adjacent P and their adsorption energies are in the range of −4.29 eV to −1.59 eV. Meanwhile, the large ratio of the adsorption energy to the cohesive energy of the metal bulk phase indicates that TM atoms have a preferred 2D growth mode on the edge hydrogenated armchair phosphorene nanoribbons (H-APNRs). The magnetic moments reduce by about 2–4 μB, relative to their free atom states, depending on whether the TM atom is in the high-spin or low-spin state. This reduction is mainly attributed to the electrons transferring from the high-level TM 4s shell to the low-lying 3d shell. Our results demonstrate that TM atom adsorption is a feasible approach to functionalizing the H-APNRs chemically, which results in peculiar electronic and magnetic properties for potential applications in nano-electronics and spintronics. [ABSTRACT FROM AUTHOR]

Developing advanced anode materials with multi-electron reaction, adequate charge transport, and suppressed volume changes is highly desirable in lithium storage. Both polyoxometalates (POMs) and metal–organic frameworks (MOFs) are attractive candidates for anode materials because of strong multi-electron redox properties of the former and high surface areas and controllable porosities of the latter. However, the easy dissolution of POMs in an electrolyte and the intrinsically poor conductivity of MOFs result in inferior rate performance and cycling capacity. In this paper, we skillfully encapsulate ionic liquids (ILs) into polyoxometalate-based metal–organic frameworks (POMOFs) to fabricate a series of ILs-functionalized POMOF crystals (denoted as POMs-ILs@MOFs), in which POMs are immobilized in MOF cages to avoid the leaching of POMs. Also, an enhanced conductivity is obtained by the modification of ILs. One of the POMs-ILs@MOFs crystals, PMo10V2-ILs@MIL-100, when used as the anode material, shows superior cycling stability and high rate capability, which is proven to be the best amongst those of all the reported MOF, POM, and POMOF crystal materials. The outstanding performances are attributed to the hybrid behavior of a battery and a supercapacitor, which results from the synergistic effects of ILs, POMs, and MOFs. Most importantly, we not only discover a series of new anode materials but also propose a new strategy to improve the conductivity of MOFs and POMOFs, which will guide the development of other electrode materials based on MOFs and POMOFs for lithium storage. [ABSTRACT FROM AUTHOR]

The relatively low capacity and poor rate performance of cathodes restrict the development of rechargeable batteries and must be settled urgently due to the ever-growing need of energy storage. Here, we report a new cathode system that produces polyoxometalates (POMs)/ionic liquid (IL)/reduced graphene oxide (RGO) composites, denoted as PIG, by a self-assembly method in which IL plays the role of “killing two birds with one stone”. IL not only facilitates the formation of heterogeneous nanocrystalline composites but also acts as the template reagent to feature the morphology of homogeneous nanobelts on the RGO. The PIG system provides us with a theoretical model at the molecular level to give a detailed comparison of a three-dimensional open skeleton formed by different transition metal linkers and a vanadium cage, on the performance of the cathode in batteries. Finally, the targeted composite Mn3V19-HIL/RGO-1 shows good cycling stability and the best ultrafast rate capabilities (121 mA h g−1 at 5000 mA g−1 and 73 mA h g−1 at 2000 mA g−1 for lithium and sodium ion batteries) of POMs-based composites. Furthermore, the PIG system provides a platform for the design of POMs, and even anionic clusters-based composites in the energy conversion and storage, thus giving access to their versatile architectural design and applications. [ABSTRACT FROM AUTHOR]

A novel polyoxometalate-based metal–organic framework (POMOF) with an ABW network, NENU-601, was synthesized in situ. To the best of our knowledge, this is the first POMOF with a zeolite-like structure, which was designed by regulating the length and angle of mixed ligands and rationally choosing suitable Polyoxometalates (POMs) as nodes. [ABSTRACT FROM AUTHOR]

A novel polyoxometalate-based metal–organic framework (POMOF), [PMo8VMo4VIO37(OH)3Zn4][TPT]5·2TPT·2H2O (NNU-11, TPT = tris-(4-pyridyl)triazine), was synthesized. Zn-ε-Keggin fragments were directly connected with TPT ligands generating 2D layers and further interdigitated with each other by π–π stacking interactions to pack into a 3D array. The compound exhibited excellent stability in air and different organic solvents and even in different pH (pH 1–11) aqueous solutions. It can be utilized as an anode material for lithium ion batteries (LIBs) due to the combination of the multi-electron redox property of POM units and the functionalization of MOFs. NNU-11 exhibited a highly reversible capacity of 750 mA h g−1 at a current density of 50 mA g−1 after 200 cycles along with excellent cycle stability and rate performance. More importantly, for the first time, we designed and synthesized a POMOF crystalline structure model supported by π–π stacking interactions to demonstrate that intermolecular π–π stacking interactions are beneficial to promote the performance of LIBs. [ABSTRACT FROM AUTHOR]

Two novel isostructural polyoxometalate (POM)-based metal–organic frameworks (MOFs) with diamond topology, NENU-506 and NENU-507, were hydrothermally synthesized. They not only combine the advantages of both POMs and MOFs, but also show excellent chemical and thermal stability. Notably, NENU-507 exhibited a high reversible capacity of 640 mA h g−1 after 100 cycles when applied as an anode material in lithium-ion batteries. [ABSTRACT FROM AUTHOR]

The slow kinetics of the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR) have hindered energy conversion and storage greatly. Design of a new class of low-cost and highly efficient electrocatalysts for the water–oxygen redox cycle (WORC) system including OER and ORR is considered a huge challenge. Controlled synthesis of unique and stable precursors as a perfect platform to synthesize target products with diverse compositions are of vital importance. Herein, we synthesized a metal/metal carbide-based composite (denoted as Co–Mo–C/NRGO-1) by directly carbonizing Co-doped polyoxometalate/conductive polymer/graphene precursor (Co-PCG) as an efficient bi-functional electrocatalyst. The resulting Co–Mo–C/NRGO-1 composite exhibited superior electrocatalytic activity for OER with an ultra-low Tafel slope of 42 mV dec−1, a small overpotential of 330 mV vs. RHE at the current density of 10 mA cm−2 and long-term stability in alkaline medium. The ORR performance was also investigated with a positive onset potential (∼−95 mV vs. Ag/AgCl), remarkable stability over 30 000 s and good tolerance to methanol crossover. Most importantly, the OER performance of Co–Mo–C/NRGO-1 was the best among all the reported carbide-based materials and was comparable to the best OER electrodes. [ABSTRACT FROM AUTHOR]