2D Carbon Nanosheets Research Articles

WO2–N co-doped 2D Carbon nanosheets as multifunctional additives for enhancing the electrochemical hydrogen storage performance of Co2B

Co2B, with its high theoretical hydrogen storage capacity, is a potential solid-state hydrogen storage material. However, its poor cycling life limits its practical application. In this work, in order to improve the cycling stability and reversibility of hydrogen absorption and desorption of Co2B, we propose to use WO2–N–C nanosheets as dopants to mix with Co2B, thereby enhancing its practical performance. Two-dimensional tungsten oxide-nitrogen-carbon (WO2–N–C) nanosheets was syntheized via a liquid-phase approach, using a tungstenate-polydopamine precursor followed by thermal treatment. Subsequently, these WO2–N–C nanosheets were compounded with cobalt boride (Co2B) particles through ball milling at various ratios of 1%, 3%, and 5%, which were confirmed by XRD (X-ray diffraction) and SEM (Scanning Electron Microscope) methods. Employing a comprehensive suite of electrochemical analyses, including corrosion potential measurements, polarization curves, step voltammetry, and electrochemical impedance spectroscopy (EIS), we found that the incorporation of WO2–N–C significantly enhances the corrosion resistance and electrochemical activity of Co2B. Furthermore, cyclic life tests revealed that the WO2–N–C-doped Co2B composites exhibit superior discharge capacities and capacity retention rates compared to pristine Co2B. Notably, the 3% WO2–N–C-doped Co2B composite demonstrated the optimal electrochemical performance, achieving a maximum discharge specific capacity of 555 mAh g−1 and maintaining 82% of its initial capacity after 50 cycles. Our findings underscore the dual role of WO2–N–C in not only augmenting the surface electrochemical activity of Co2B but also providing a protective surface layer, thereby enhancing its overall electrochemical performance.

3D Co-doped carbon nanosheets as high-performance electrodes for Li-S batteries

3D petal-shaped Cobalt-doped carbon nanosheets (PCoCNS) were synthesized as excellent sulfur hosts for lithium-sulfur (Li-S) batteries. Co doping enhanced the affinity of the carbon surface for lithium polysulfides (LiPSs), inhibiting the shuttle effect. The electrocatalytic effect of the PCoCNS electrode exhibited enhanced polysulfide conversion kinetics, thereby promoting Li2S formation. Owing to the above advantages, the PCoCNS cathode exhibited satisfactory reversibility of 841 mAh/g with a high capacity retention of 91 %. Additionally, it displayed high coulombic efficiency (CE) values exceeding 97 % over 100 cycles at a current rate of 0.5C. Furthermore, the electrode demonstrated low polarization and exhibited an excellent rate performance, delivering a capacity of 575 mAh/g at the high rate of 3C. This study synthesized a promising sulfur cathode for enhancing the electrochemical performance of Li-S batteries.

RETRACTED: Fe–Co co-doped 1D@2D carbon-based composite as an efficient catalyst for Zn-air batteries

A Fe-Co dual-metal co-doped nitrogen-containing carbon composite (FeCo-HNC) was prepared by adjusting the ratio of iron to cobalt as well as the pyrolysis temperature with the assistance of functionalized silica template. Fe1Co-HNC, which was made from 1D carbon nanotubes and 2D carbon nanosheets with a rich mesoporous structure, presented exceptional oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalytic activity. The ORR half-wave potential is 0.86 V (vs. reversible hydrogen electrode, RHE), and the OER overpotential is 0.76 V at 10 mA cm−2 with the Fe1Co-HNC catalyst, which can be applied to zinc-air batteries with superior performance. It is worth noting that the zinc-air batteries with Fe1Co-HNC-1000 as the cathodic catalyst achieved the highest power density of 94.9 mW cm−2 under a current density of 159.8 mA cm−2. This method provides a promising strategy for fabricating efficient transition metal-based carbon catalysts.

CoSe2-Modified multidimensional porous carbon frameworks as high-Performance anode for fast-Charging sodium-Ion batteries

Transition metal selenides (TMSs) possess relatively high theoretical capacity and unique structures emerge as promising anode materials for sodium-ion batteries (SIBs). However, TMSs anode materials suffer from challenges such as substantial volume expansion, undesired side reactions, and poor active reaction dynamics. Herein, we propose a novel synthesis method that integrates metal salt-assisted polymer-blowing technique with in situ selenization strategy to fabricate multidimensional porous 3D carbon nanosheet frameworks modified by cobalt diselenide nanoparticles (CoSe2-CNF). Such unique architecture bestows intimate structural interconnectivity with high mechanical strength and abundant ion diffusion channels on CoSe2-CNF, exhibiting remarkable reversible capacity and fast-charging capability within diverse electrolyte systems. For instance, the CoSe2-CNF anode in ether electrolyte exhibits prominent rate performance of 349 mAh/g at 15 A/g. Sodium storage mechanism and fast electrochemical kinetics in the discharge/charge processes are investigated by in situ XRD and in situ EIS techniques. Additionally, DFT calculations are utilized to analyze the electrochemical differences observed in various electrolyte systems. When coupled with Na3V2(PO4) (NVP) cathodes, the full batteries also afford enhanced reversible capacity of 105 mAh/g over 100 cycles. The proposed structural engineering for CoSe2-CNF is beneficial for designing fast-charging energy storage devices.

Mo2C-Co heterostructure with carbon nanosheets decorated carbon microtubules: Different means for high-performance lithium-sulfur batteries

The practical applications of lithium sulfur batteries (LSBs) are hindered by notorious shuttle effect and sluggish conversion kinetics of intermediate polysulfides. Herein, Mo2C-Co heterogeneous particles decorated two-dimensional (2D) carbon nanosheets grown on hollow carbon microtubes (CCC@MCC) are synthesized. Three-dimensional (3D) carbon framework with Mo2C-Co heterogeneous particles combines the conductivity, adsorption and catalysis, effectively trapping and accelerating the conversion of polysulfides. As evidenced experimentally, the hetero-structured Mo2C-Co with high Li+ diffusion coefficient enables uniform precipitation and complete oxidation of Li2S. Meanwhile, CCC@MCC is found to have multiple application possibilities for lithium-sulfur batteries. As an interlayer, the cells deliver an excellent capacity of 881.1 mAh/g at 2C and still retain 438.2 mAh/g after 500 cycles under the low temperature of 0 ℃. As a sulfur carrier, the cell with a sulfur loading of 7.0 mg cm−2 exhibits a high area capacity of 5.3 mAh cm−2. This work provides an effective strategy to prepare heterostructured material and imaginatively exploit the application potential of it.

Scalable Production of 2D Non‐Layered Metal Oxides through Metal–Organic Gel Rapid Redox Transformation

Two‐dimensional (2D) nonlayered metal compounds with porous structure show broad application prospects in electrochemistry‐related fields due to their abundant active sites, open ions/electrons diffusion channels, and faradaic reactions. However, scalable and universal synthesis of 2D porous compounds still remains challenging. Here, inspired by blowing gum, a metal‐organic gel (MOG) rapid redox transformation (MRRT) strategy is proposed for the mass production of a wide variety of 2D porous metal oxides. Adequate crosslinking degree of MOG precursor and its rapid redox with NO3‐ are critical for generating gas pressure from interior to exterior, thus blowing the MOG into 2D carbon nanosheets, which further act as self‐sacrifice template for formation of oxides with porous and ultrathin structure. The versatility of this strategy is demonstrated by the fabrication of 39 metal oxides, including 10 transition metal oxides, one II‐main group oxide, two III‐main group oxides, 22 perovskite oxides, four high‐entropy oxides. As an illustrative verification, the 2D transition metal oxides exhibit excellent capacitive deionization (CDI) performance. Moreover, the assembled CDI cell could act as desalting battery to supply electrical energy during electrode regeneration. This MRRT strategy offers opportunities for achieving universal synthesis of 2D porous oxides with nonlayered structures and studying their electrochemistry‐related applications.

Scalable Production of 2D Non-Layered Metal Oxides through Metal-Organic Gel Rapid Redox Transformation.

Two-dimensional (2D) nonlayered metal compounds with porous structure show broad application prospects in electrochemistry-related fields due to their abundant active sites, open ions/electrons diffusion channels, and faradaic reactions. However, scalable and universal synthesis of 2D porous compounds still remains challenging. Here, inspired by blowing gum, a metal-organic gel (MOG) rapid redox transformation (MRRT) strategy is proposed for the mass production of a wide variety of 2D porous metal oxides. Adequate crosslinking degree of MOG precursor and its rapid redox with NO3 - are critical for generating gas pressure from interior to exterior, thus blowing the MOG into 2D carbon nanosheets, which further act as self-sacrifice template for formation of oxides with porous and ultrathin structure. The versatility of this strategy is demonstrated by the fabrication of 39 metal oxides, including 10 transition metal oxides, one II-main group oxide, two III-main group oxides, 22 perovskite oxides, four high-entropy oxides. As an illustrative verification, the 2D transition metal oxides exhibit excellent capacitive deionization (CDI) performance. Moreover, the assembled CDI cell could act as desalting battery to supply electrical energy during electrode regeneration. This MRRT strategy offers opportunities for achieving universal synthesis of 2D porous oxides with nonlayered structures and studying their electrochemistry-related applications.

Amine-Functionalized Metal-Free Nanocarbon to Boost Selective CO2 Electroreduction to CO in a Flow Cell.

Highly efficient electrochemical CO2-to-CO conversion is a promising approach for achieving carbon neutrality. While nonmetallic carbon electrocatalysts have shown potential for CO2-to-CO utilization in H-type cells, achieving efficient conversion in flow cells at an industrial scale remains challenging. In this study, we present a cost-effective synthesis strategy for preparing ultrathin 2D carbon nanosheet catalysts through simple amine functionalization. The optimized catalyst, NCNs-2.5, demonstrates exceptional CO selectivity with a maximum Faradaic efficiency of 98% and achieves a high current density of 55 mA cm-2 in a flow cell. Furthermore, the catalyst exhibits excellent long-term stability, operating continuously for 50 h while maintaining a CO selectivity above 90%. The superior catalytic activity of NCNs-2.5 is attributed to the presence of amine-N active sites within the carbon lattice structure. This work establishes a foundation for the rational design of cost-effective nonmetallic carbon catalysts as sustainable alternatives to metals in energy conversion systems.

Fe-Co Co-Doped 1D@2D Carbon-Based Composite as an Efficient Catalyst for Zn-Air Batteries.

A Fe-Co dual-metal co-doped N containing the carbon composite (FeCo-HNC) was prepared by adjusting the ratio of iron to cobalt as well as the pyrolysis temperature with the assistance of functionalized silica template. Fe1Co-HNC, which was formed with 1D carbon nanotubes and 2D carbon nanosheets including a rich mesoporous structure, exhibited outstanding oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalytic activities. The ORR half-wave potential is 0.86 V (vs. reversible hydrogen electrode, RHE), and the OER overpotential is 0.76 V at 10 mA cm-2 with the Fe1Co-HNC catalyst. It also displayed superior performance in zinc-air batteries. This method provides a promising strategy for the fabrication of efficient transition metal-based carbon catalysts.

Interfaces Engineering of Ultrafine Ni@Ni2P/C Core-Shell Heterostructure for High Yield Hydrogen Peroxide Electrosynthesis.

Developing cost-effective and sustainable catalysts with exceptional activity and selectivity is essential for the practical implementation of on-site H2O2 electrosynthesis, yet it remains a formidable challenge. Metal phosphide core-shell heterostructures anchored in carbon nanosheets (denoted as Ni@Ni2P/C NSs) are designed and synthesized via carbonization and phosphidation of the 2D Ni-BDC precursor. This core-shell nanostructure provides more accessible active sites and enhanced durability, while the 2D carbon nanosheet substrate prevents heterostructure aggregation and facilitates mass transfer. Theoretical calculations further reveal that the Ni/Ni2P heterostructure-induced optimization of geometric and electronic structures enables the favored adsorption of OOH* intermediate. All these features endow the Ni@Ni2P/C NSs with remarkable performance in 2e ORR for H2O2 synthesis, achieving a top yield rate of 95.6mgL-1h-1 with both selectivity and Faradaic efficiency exceeding 90% under a wide range of applied potentials. Furthermore, when utilized as the anode of an assembled gas diffusion electrode (GDE) device, the Ni@Ni2P/C NSs achieve in situ H2O2 production with excellent long-term durability (>32h). Evidently, this work provides a unique insight into the origin of 2e ORR and proposes optimization of H2O2 production through nano-interface manipulation.

A synthesis strategy of 3D carbon nanosheet anode with adsorption/intercalation-filling hybrid mechanism for high-performance sodium/potassium-ion batteries

Hard carbons are significant in sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs). However, the structural defects of hard carbons lead to poor rate performance and cycling stability, which need further improvement. The waste cooking oil was used as the precursor to synthesize 3D carbon nanosheets (NWCOC) with amino nitrogen functional groups, multi-layered pores, and expanded interlayer spacing. The excellent electrochemical properties of NWCOC were investigated and it was demonstrated that NWCOC can significantly improve the adsorption of Na+/K+ on hard carbons, substantially enhancing the embedding/de-embedding of Na+/K+, reducing the diffusion distance of ions and electrons, and improving their adaptability to volume changes. In situ XRD and Raman characterization reveal that the Na storage mechanism of NWCOC is mainly based on adsorption/intercalation-filling. Combined with density functional theory, it is shown that the porous structures doped with nitrogen have a greater propensity for ion adsorption, resulting in increased ion capture and storage. As expected, NWCOC650 exhibits high capacities of 489.4 and 388.3 mAh/g in SIBs and PIBs. NWCOC650 displays superior performance in the Na3V2(PO4)3/NWCOC650 full cell, achieving a capacity of 107.84 mAh/g. This work presents a new perspective on the synthesis and mechanisms of high-performance anodes for SIBs and PIBs.

Allying interfacial engineering of 2D carbon nanosheet‐, graphene‐, and graphdiyne‐based heterostructured electrocatalysts toward hydrogen evolution and overall water splitting

AbstractElectrochemical hydrogen evolution reaction (HER) and overall water splitting (OWS) for renewable energy generation have recently become a highly promising and sustainable strategy to tackle energy crisis and global warming arising from our overreliance on fossil fuels. Previously, tremendous research breakthroughs have been made in 2D carbon‐based heterostructured electrocatalysts in this field. Such heterostructures are distinguished by their remarkable electrical conductivity, exposed active sites, and mechanical stability. Herein, with fundamental mechanisms of electrocatalytic OWS summarized, our review critically emphasized on state‐of‐the‐art 2D carbon nanosheet‐, graphene‐, and graphdiyne‐based heterostructured electrocatalysts in HER and OWS since 2018. Particularly, the three emerging carbonaceous substrates tend to be incorporated with metal carbides, phosphides, dichalcogenides, nitrides, oxides, nanoparticles, single atom catalysts, or layered double hydroxides. Meanwhile, fascinating structural engineering and facile synthesis strategies were also unraveled to establish the structure–activity relationship, which will enlighten future electrocatalyst developments toward ameliorated HER and OWS activities. Additionally, computational results from density functional theory simulations were highlighted as well to better comprehend the synergistic effects within the heterostructures. Finally, current stages and future recommendations of this brand‐new electrocatalyst type were concluded and discussed for advanced catalyst designs and future practical applications.

Dual Activation for Tuning N, S Co-Doping in Porous Carbon Sheets Toward Superior Sodium Ion Storage.

Porous carbon has been widely focused to solve the problems of low coulombic efficiency (ICE) and low multiplication capacity of Sodium-ion batteries (SIBs) anodes. The superior energy storage properties of two-dimensional(2D)carbon nanosheets can be realized by modulating the structure, but be limited by the carbon sources, making it challenging to obtain 2D structures with large surface area. In this work, a new method for forming carbon materials with high N/S doping content based on combustion activation using the dual activation effect of K2SO4/KNO3 is proposed. The synthesized carbon material as an anode for SIBs has a high reversible capacity of 344.44mAhg-1 at 0.05Ag-1. Even at the current density of 5Ag-1, the capacity remained at 143.08mAhg-1. And the ICE of sodium-ion in ether electrolytes is ≈2.5 times higher than that in ester electrolytes. The sodium storage mechanism of ether/ester-based electrolytes is further explored through ex-situ characterizations. The disparity in electrochemical performance can be ascribed to the discrepancy in kinetics, wherein ether-based electrolytes exhibit a higher rate of Na+ storage and shedding compared to ester-based electrolytes. This work suggests an effective way to develop doubly doped carbon anode materials for SIBs.

1D hollow tubular/2D nanosheet hybrid dimensional porous carbon prepared by one-step carbonization using natural minerals as templates for supercapacitors.

The reasonable construction of one-dimensional (1D)/two-dimensional (2D) hybrid dimensional porous carbon materials with complementary advantages and disadvantages is an important approach to addressing the structural and performance deficiencies of single carbon materials, while also significantly improving the electrochemical performance of super-capacitors. In this study, 1D hollow tubular/2D nanosheet hybrid dimensional porous carbon was synthesized through one-step carbonization using 1D fibrous brucite and 2D layered magnesium carbonate hydroxide as templates. By adjusting the feed ratio of 1D fibrous and 2D layered templates, the morphology, pore structure and specific surface area (SSA) of the prepared 1D hollow tubular/2D nanosheet hybrid dimensional porous carbon were controlled. The prepared hybrid dimensional porous carbons were characterized using scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and nitrogen adsorption-desorption. And their electrochemical performance was also studied by cyclic voltammograms (CV), galvanostatic charge/discharge (GCD) and electrochemical impedance spectroscopy (EIS). The results show that the use of templates with different dimensions significantly influences the morphology, pore structure, SSA and electrochemical performance of the synthesized hybrid dimensional porous carbon. The hybrid dimensional porous carbon (3F) exhibits a high specific capacitance and excellent cycling stability. 3F demonstrates the specific capacitance of 245.3 F g-1 at 1 A g-1. Furthermore, the capacity retention rate remains as high as 93.4% after 8000 cycles at 10 A g-1. This work reveals that hybrid dimensional porous carbon composed of 1D hollow carbon tubes and 2D carbon nanosheets has great potential for use in supercapacitor electrode materials.

A nanoelectrode of hybrid nanomaterials of palladium oxide with cadmium sulfide based on 2D-carbon nanosheets for developing electron transfer efficiency for supercapacitor applications

A layered nanoelectrode design was based on the high surface area of graphene oxide and reduced graphene oxide; these layers were decorated with n/p-type palladium oxide nanoparticles (NPs) and cadmium sulfide NPs.

The synergy of Co-MoN-MgO on 2D carbon sheets for effective catalytic hydrogenation

The Co-based materials are the promising catalysts for the catalytic hydrogenation reactions. The optimization of the electronic structure and micro-morphology to achieve like-noble-metal catalysis is a current research hotspot. Here, the Co-MoN-MgO heterojunctions embedded on 2D carbon nanosheets (Co-MoN-MgO/C) were designed in a melt-salt system for efficient catalytic hydrogenation of the nitro-compounds. The tests show the intimate contact of Co with MoN, realizing effective synergy for promoting the electrons transfer from Co to MoN. The transfer optimizes the electronic structure of Co components, being favorable for the adsorption/desorption of intermediates and catalytic hydrogenation reaction. The 2D porous structure gives enhanced mass-transfer ability and large accessible surface for better contact with the reactants. Above features endow Co-MoN-MgO/C with good catalytic activity for p-nitrophenol (4-NP) hydrogenation, with a reaction rate constant k of 0.41 min−1 (10 °C), which is 2.73 times greater than Co-MgO/C catalyst (0.15 min−1) and even better than some reported noble-metal catalysts. Furthermore, the catalyst shows good cycling stability with no obvious deactivation after 10 cycles and obvious catalytic activity for a series of nitro-compounds. This work has important implications for the design of efficient non-noble-metal synergistic catalyst for the effective catalytic hydrogenation.

Mo2N quantum dots decorating N-doped carbon nanosheets for kinetics-enhanced Li-S batteries

Lithium-sulfur (Li-S) batteries face two main challenges, which are the severe shuttle effect of lithium polysulfides (LiPSs) and the slow redox kinetics of LiPSs. Herein, monodispersed Mo2N quantum dots decorating N-doped carbon nanosheets (Mo2N@NCNS) are rationally engineered via a simple and cost-effective method and used as an effective host for sulfur in high-performance Li-S batteries. Mo2N@NCNS presents enhanced intrinsic conductivity, superior catalytic capability, and improved LiPSs redox kinetics. The 3D N-doped carbon nanosheet networks endowed with abundant catalytic sites can heighten physically confined and chemically adsorptive LiPSs by strongly polar-polar interactions, further regulating the disordered motion of LiPSs. In the meanwhile, the highly dispersed Mo2N quantum dots with powerful adsorptive-catalytic properties anchor the soluble LiPSs and facilitate high-efficiency diffusion-conversion kinetics for the nucleation and deposition of Li2S2/Li2S, thus promoting the complete utilization of sulfur and the overall enhancement of electrochemical performance. Owing to these fascinating features, the Mo2N@NCNS-based sulfur cathodes demonstrate substantial enhancement in electrochemical performance, including remarkable capacity performance (1221 mAh g−1 at 0.2 C) and exceptional cyclability over 800 cycles at 2 C with a minimal decay rate (0.03 % per cycle). This work highlights the great potential of rational design of advanced composite materials for promoting the practical viability of Li-S batteries in energy storage systems.

Selective oxidation of organic pollutants based on reactive oxygen species and the molecular structure: Degradation behavior and mechanism analysis

The selective and rapid elimination of refractory organic pollutants from surface water is significant. However, the relationship of between reactive oxygen species (ROSs) and diversified pollutants molecular structures still needs to be further clarified. Here, we utilize polydopamine (PDA)-assisted coating strategy to prepare hollow 2D carbon nanosheet (ZPL-HCNS) and 2D Co3O4 nanosheet (ZPL-Co3O4) by thermolysis of PDA coated ZIF-L (ZIF-L@PDA) precursor under different gas atmosphere, which realizes the controlled generation of radicals and non-radicals. Organic pollutants including bisphenols, sulfonamides, quinolones, tetracyclines, and azo dyes are applied to assess the catalytic performance. Results show that dyes containing azo structure are more likely to be degraded by radical process, which is due to that the energy (ΔE) requirements to break the azo bond is higher than energy released from singlet oxygen to oxygen molecule and lower than that of sulfate radical to sulfate. Frontier molecular orbital theory HOMO-LUMO and Fukui function expounded the possible selectivity mechanism. In addition, the degradation pathway and biotoxicity test are carried out. This work provides a reference to illustrate the selective degradation for ROSs and molecular structure of pollutants.

NiSe nanoparticles decorated corn stalk derived 2D carbon nanosheet as separator modifier for high-performance lithium-sulfur batteries

Lithium-sulfur (Li–S) batteries are considered as the most promising successors of lithium-ion batteries, however, the shuttle effect and sluggish reaction kinetics are the biggest obstacles hindering their commercialization. In this work, a kind of NiSe nanoparticles embedded in corn stalk-derived two-dimensional (2D) porous carbon nanosheet (NiSe@CSC) is constructed as a separator modifier for advanced Li–S batteries. The rich pore structure of the corn stalk-derived carbon nanosheets enables uniform distribution of NiSe and provides more deposition sites for lithium polysulfides (LiPS). Electrochemical analyses show that NiSe increases the affinity for LiPS to suppress the shuttle effect, thereby effectively preventing the corrosion of polysulfide on the lithium anode. NiSe@CSC is found to accelerate the redox conversion of sulfur species in the kinetic study. Consequently, the assembled Li–S cells with NiSe@CSC coating layer exhibit a high-rate performance of 710 mAh g−1 at 3 C and a low capacity attenuation rate of 0.046% per cycle after 800 cycles at 1 C. Furthermore, it can still maintain 2.8 mAh cm−2 at 0.5 C in near-commercial application scenarios of 4.1 mg cm−2 sulfur loading. The NiSe@CSC-based Li–Li symmetric cells also demonstrate stability and low overpotential in protecting the lithium anode. This combination of renewable biomass-based carbons and transition metal selenides enriches the exploration of biomass materials in separators and provides new ideas for designing practical Li–S batteries.

Co-Ru alloy nanoparticles decorated onto two-dimensional nitrogen doped carbon nanosheets towards hydrogen/oxygen evolution reaction and oxygen reduction reaction

Constructing highly-efficient electrocatalysts toward hydrogen evolution reaction (HER)/oxygen evolution reaction (OER)/oxygen reduction reaction (ORR) with excellent stability is quite important for the development of renewable energy-related applications. Herein, Co-Ru based compounds supported on nitrogen doped two-dimensional (2D) carbon nanosheets (NCN) are developed via one step pyrolysis procedure (Co-Ru/NCN) for HER/ORR and following low-temperature oxidation process (Co-Ru@RuOx/NCN) for OER. The specific 2D morphology guarantees abundant active sites exposure. Furthermore, the synergistic effects arising from the interaction between Co and Ru are crucial in enhancing the catalytic performance. Thus, the resulting Co-Ru/NCN shows remarkable electrocatalytic performance for HER (70 mV at 10 mA cm−2) in 1 M KOH and ORR (half-wave potential E1/2 = 0.81 V) in 0.1 M KOH. Especially, the Co-Ru@RuOx/NCN obtained by oxidation exhibits splendid OER performance in both acid (230 mV at 10 mA cm−2) and alkaline media (270 mV at 10 mA cm−2) coupled with excellent stability. Consequently, the fabricated two-electrode water-splitting device exhibits excellent performance in both acidic and alkaline environments. This research provides a promising avenue for the advancement of multifunctional nanomaterials.