Heteroatom-doped Carbon Materials Research Articles

Two-dimensional covalent organic frameworks as self-template derived nitrogen-doped carbon nanosheets for eco-friendly metal-free catalysis

Heteroatom-doped carbon materials with superior physico-chemical properties and high stability are potential candidates for environmentally friendly metal-free catalysis. In this study, mesoporous carbon materials with high N content and lattice defects were successfully fabricated via self-templated carbonization of a two-dimensional covalent organic framework (2D COF). The ordered structure and clear composition of intrinsic COF precursors aid the understanding of the specific role of dopants in the as-prepared N-doped mesoporous carbon materials. Based on the obtained experimental results and characterizations, graphitic N and its related defects were found to be closely associated with catalytic activity, indicating they are probably the main active sites. In addition, the obtained catalyst showed remarkable catalytic performance in both hydrogenation of nitroarenes and Knoevenagel condensation of aromatic aldehyde derivatives in aqueous solution. This study is expected to provide a new inspiration for the synthesis of heteroatom-doped carbon materials from cost-effective COFs via self-templated carbonization for eco-friendly metal-free catalysis.

Cellulose-derived nitrogen-doped hierarchically porous carbon for high-performance supercapacitors

Heteroatom-doped porous carbon materials are one of the most promising electrodes for high-performance supercapacitors. However, the development of a simple, green and low-cost strategy for their preparation is still highly challenging. In this study, we reported a simple and sustainable preparation of nitrogen-doped hierarchically porous carbon (NHPC) by using cellulose as raw materials. A NaOH/urea (7:12) system acted as the solvent, activator, and dopant simultaneously. The resultant NHPC has a high BET specific surface area of 2245 m2 g−1, a typically porous architecture comprising of micro-, meso-, and macropores with an appropriate average pore size of 2.83 nm, as well as a suitable nitrogen-doping degree of 3 wt%. The unique features of NHPC afford an outstanding specific capacitance of 300 F g−1 at 0.5 A g−1, representing a new capacitive record among the cellulose-derived carbon electrodes reported so far. The NHPC//NHPC supercapacitor cell displays a high energy density of 17.2 Wh kg−1 at 452 W kg−1, and maintains 12.1 Wh kg−1 at 4500 W kg−1. High rate capability (81% of capacitance retention from 0.5 to 10 A g−1) and excellent cycling stability (5% loss after 10,000 cycles) have been also demonstrated. The facile and affordable synthesis route together with outstanding energy storage behavior endows the cellulose-derived NHPC with promising application for supercapacitors.

Self-templating synthesis nitrogen and sulfur co-doped hierarchical porous carbons derived from crab shells as a high-performance metal-free oxygen electroreduction catalyst

Heteroatom-doped carbon materials with high activity, chemical stability and low cost, as promising metal-free electrocatalyst candidates to replace commercial Pt/C catalysts stand for the main challenge precluding their practical applications and commercialization in oxygen reduction reactions (ORR) of metal–air batteries and fuel cells. Here, we report a green and scalable fabrication of hierarchical porous carbons with honeycomb-like structure as a high-performance metal-free catalyst toward ORR, via one-step pyrolysis of crab shells. The nitrogen and sulfur co-doped carbons with a morphology containing macro-, micro-, and mesopores were obtained, avoiding the use of template agent and activated process. The pyrolysis temperature of crab shells played a critical role in the heteroatom content, pore structure and active site as well as electro catalytic performance of the resulting carbon catalyst. The optimal carbon catalyst pyrolyzed at 900 °C exhibits excellent ORR activity with an onset potential of 0.072 V and a half-potential of −0.110 V (vs. Ag/AgCl) in alkaline electrolytes, and superior methanol tolerance durability to the commercial Pt/C. Our as-obtained carbons will certainly be expected to open a trend setter and generate substantial economic values by creating value-added materials from waste.

Synthesis of Biomass-Derived Carbon Induced by Cellular Respiration in Yeast for Supercapacitor Applications.

Because activated carbon is extensively used in supercapacitors, optimization of its precursors and synthetic strategies are crucial. Inspired by the rich sugar content of banana peel waste, which can be transformed through the respiration of yeast into alcohol with the release of CO2 , we developed an environmentally benign and highly efficient process for the production of renewable heteroatom-doped hierarchical porous carbon materials (yeast-treated banana-peel-based carbon, denoted as YBP) without any additional templates or activation agents. The resulting biologically activated carbon was characterized by near-edge X-ray absorption fine-structure spectroscopy, X-ray photoelectron spectroscopy, and other physical methods. The biologically activated carbon achieved a maximum gravimetric specific capacitance of 476 F g-1 in 1 m H2 SO4 electrolyte. Remarkably, with a moderate specific surface area of 1084 m2 g-1 , the as-obtained activated carbon was found to have a high packing density. With enriched pseudocapacitance sites, the YBP symmetric supercapacitor has a high volumetric specific capacitance and energy density (maximum values of 264 F cm-3 and 23.5 Wh L-1 , respectively). The supercapacitor showed superior cyclic stability, with 94 % capacitance retention for voltage values up to 1.6 V after 10 000 cycles, which confirmed the promising application of this supercapacitor in miniature electronic devices.

Constructing Successive Active Sites for Metal‐free Electrocatalyst with Boosted Electrocatalytic Activities Toward Hydrogen Evolution and Oxygen Reduction Reactions

AbstractAs well known, heteroatom doped carbon material served as metal‐free electrocatalyst for hydrogen evolution (HER) and oxygen reduction reactions (ORR) particularly relies on the heteroatom doping level. Here, we report a 3D porous nitrogen doped carbon (PNC) electrocatalyst with superior HER and ORR electrocatalytic activities derived from the calcination of the discarded cigarette butt and dicyandiamide possessing a high nitrogen content (20 at%). PNC electrocatalyst only demands 143 mV versus RHE to achieve 10 mA cm−2 ascribed to the high nitrogen percentile in PNC electrocatalyst favorable for constructing successive active centers contributing to efficiently catalyzing HER. Ignorable degradation in HER activity observed after 10000 potential cycles as well as undetectable decay in HER performance recorded after 12 h operation indicate high stability of PNC electrocatalyst. Meanwhile, half‐wave potential of PNC electrocatalyst reaches 0.81 V versus RHE in 1 M KOH electrolyte. Additionally, stable ORR activity attained after 1000 potential cycles is indicative of high stability. A comparably high zinc‐air battery performance with maximum power density of 66 mW cm−2 is achieved by PNC electrocatalyst. This study highlights the importance of nitrogen doping level in metal‐free electrocatalyst for boosting HER and ORR activities.

Fabrication of Microporous Sulfur-Doped Carbon Microtubes for High-Performance Sodium-Ion Batteries

Developing efficient anode materials for sodium-ion batteries (SIBs) is important for the storage of renewable energy. Inspired by the rapid development of biomass-derived hard carbons and heteroatom-doped carbon materials in various areas, a high-temperature sulfurizing method is exploited for the fabrication of sulfur-doped carbon microtubes (S-CMTs). Owing to high sulfur doping (10.2 wt %) and well-developed microporous structure, the as-prepared S-CMTs show a large charge capacity of 532 mAh g–1 at a current rate of 200 mA g–1, outstanding rate capability (234 mAh g–1 at 2 A g–1), and exceptional cycling stability (281 mAh g–1 after 1000 cycles at 1 A g–1), values that are superior to those of biomass-derived carbons reported previously. The excellent electrochemical performance of S-CMTs in full cells paired with N,B-co-doped carbon-coated Na3V2(PO4)3 cathodes further demonstrates the feasibility of SIBs. The simple synthesis strategy can potentially be extended to other carbon-based anode materials ...

Nitrogen and Sulfur Dual Self-Doped Graphitic Carbon with Highly Catalytic Activity for Oxygen Reduction Reaction

The use of heteroatom-doped carbon materials in the oxygen reduction reaction (ORR) continues to be an attractive alternative to Pt-based catalyst. In this work, nitrogen and sulfur dual self-doped hierarchically micro- and mesoporous graphitic carbon catalyst was prepared by pyrolysis of methyl orange (Fe (III)) complex, followed by removing the metal species in acid. The catalyst shows high electrocatalytic activity, long-term stability and tolerance for methanol in both acidic and alkaline media. Especially, the catalyst exhibits superior ORR electrocatalytic activity than that of the commercial Pt/C (20 wt %) in 0.1 M KOH: 0.962 and 0.865 V (vs RHE) of onset and half-wave potential was obtained, which is 8/22 mV positive than that for Pt/C, respectively. Additionally, the catalyst exhibits much greater stability than Pt/C. Kinetics investigations show that the catalyst follows the efficient 4-electron pathway for ORR in both the alkaline and acidic electrolyte.

Metal Nanoparticles Supported on Biomass-Derived Hierarchical Porous Heteroatom-Doped Carbon from Bamboo Shoots: Design, Synthesis and Applications.

Heteroatom-doped porous carbon derived from biomass have recently received increasing attention due to their unique properties such as high electrical conductivity, large specific surface area, high porosity, and easy availability, which are appealing materials for versatile applications in catalysis, energy, separation and adsorption, and life sciences as well. On the basis of our previous work in this field, we summarized in this account our recent progress on design, synthesis of metal (e. g., Pd, Co) nanoparticles supported heteroatom-doped hierarchical porous carbon material derived from bamboo shoots and their applications for important organic transformations, including chemoselective semihydrogenation of alkynes, hydrosilylation of alkynes, cascade synthesis of benzofurans from terminal alkynes and iodophenols, selective hydrogenation of functionalized nitroarenes to form anilines, imines, and formamides. Finally, the current state and future challenges in this field are discussed. We hope this account could shed light on the rational design of novel non-noble metal based heterogeneous catalysts derived from biomass for efficient and sustainable organic transformations.

Two-dimensional covalent-organic-framework-derived nitrogen-rich carbon nanosheets modified with small Pd nanoparticles for the hydrodechlorination of chlorophenols and hydrogenation of phenol

Heteroatom-doped carbon materials have attracted immense attention for heterogeneous catalysis applications because of their excellent physicochemical properties. In this work, we prepared a cost-effective triazinyl-containing two-dimension COFs (2D-COFs), and then the 2D-COFs was self-templated carbonized to fabricate 2D nitrogen-doped carbon nanosheets (NCNs). NCNs were modified with highly dispersed small palladium nanoparticles (Pd NPs), affording the Pd/NCNs catalyst. The as-prepared NCNs and Pd/NCNs exhibited a smoke-like morphology, a large specific surface area, and mesoporous and macroporous structures, which can enhance reactants diffusion and mass transfer. The obtained Pd/NCNs catalyst exhibited excellent activity, stability, and recyclability in the aqueous-phase hydrodechlorination (HDC) of organic hazardous substances chlorophenols (CPs). Meanwhile, outstanding activity and high selectivity were observed for the subsequent hydrogenation of the HDC product phenol to cyclohexanone. The excellent activity of the Pd/NCNs catalyst was related to the synergistic effect of Pd NPs and the nitrogen atoms doped in the NCNs. Thus, this study offers a novel, facile route for fabrication heteroatom-doped carbon materials derived from cost-effective COFs materials to prepare highly dispersed small noble-metal-NP-modified catalysts for various catalytic applications.

Bifunctional biomass-derived 3D nitrogen-doped porous carbon for oxygen reduction reaction and solid-state supercapacitor

Biomass-derived carbon materials have garnered intensive consideration in energy fields, such as fuel cells and supercapacitors, due to their inexpensive precursors, abundant resources and facile synthesis. Herein, we report a facile strategy based on taro stem precursor to synthesize a 3D nitrogen-doped porous carbon (3DNPC) with micropores, mesopores, macropores, large specific surface area (1012 m2 g−1) and nitrogen content (4.8 at%), which displays high catalytic activity and stability for oxygen reduction reaction and good electrochemical properties for supercapacitors. Compared with the commercial Pt/C catalysts, the 3DNPC-800 with 3D porous structure, proper total doped N and high graphitic N content, presents brilliant long-term stability (96.5% retention after 20,000 s) and resistance to methanol crossover for oxygen reduction reaction. With respect to electrode material of supercapacitor, the 3DNPC-800 possesses high specific capacitance (236.4F g−1 at 0.1 A g−1) and outstanding long cycle durability (89.3% retention after 10,000 cycles at 20 A g−1). Moreover, the prepared symmetric solid-state supercapacitor devices achieve outstanding power density (5 kW kg−1 at 5.56 Wh kg−1). Consequently, economically and sustainably utilization nature of materials to fabricate heteroatom-doped carbon materials, having great potential in electrochemical applications, is presented.

Tea-leaf-residual derived electrocatalyst: Hierarchical pore structure and self nitrogen and fluorine co-doping for efficient oxygen reduction reaction

The heteroatom-doped carbon materials as metal-free catalysts show great potential for oxygen reduction reaction (ORR) due to the high electrocatalytic activity, low cost, long-term stability, and environmental friendliness. Utilizing biomass as precursors has offered facile and extremely low-cost strategy to large-scale fabrication of highly efficient carbon materials with abundant pore structures and elements. In this work, tea residue was used as precursor to synthesize nitrogen (N) and fluorine (F) co-doped porous carbon materials via one-step annealing process without any activation or post-treatment. The morphology, pore structure, elemental composition of our sample as well as its electrocatalytic performance in ORR were studied. This biomass-based carbon materials has high specific surface area (855.6 m2 g−1) and hierarchical pore structure, which can offer abundant active sites and meanwhile is favorable to ion diffusion of liquid electrolyte. Secondly, the heteroatoms (especially F) doping can induce charge redistribution thanks to the electronegativity difference, which can facilitate electron transfer in ORR. When compared to commercial Pt/C, our catalyst shows a higher limited current density and a high electron transfer number of about 3.8. Finally, the catalyst also demonstrates excellent methanol tolerance in the alkaline medium. Our work provides an economical and facile strategy to synthesize efficient electrocatalyst for ORR.

3D N-doped carbon framework with embedded CoS nanoparticles as highly active and durable oxygen reduction and evolution electrocatalyst

Development of bifunctional non-metal electrocatalyst for oxygen reduction reactions (ORRs) and oxygen evolution reactions (OERs) with high efficiency, durable stability and low cost is a crucial and challenging issue. However, the heteroatom-doped carbon material including a carbon-based conductive additive would be easily oxidized under the high potential needed for driving the OER. Besides, the interaction between the heteroatom-doped carbon material that possesses electrocatalyst activity and a carbon-based conductive additive is weak, affecting the performance of the electrocatalyst. In this context, we introduce CoS nanoparticles into a three-dimensional N-doped carbon framework (CoS/NCF) by a morphology-retaining pyrolysis of polyaniline/CoS framework precursor, in which the polyaniline framework provides abundant functional groups to nucleate and grow CoS nanoparticles while retaining its interconnected three-dimensional porous structure. Benefiting from (i) the lower OER potential of CoS nanoparticles than the electro-oxidation decomposition potential of a carbon material and (ii) the strong affinity of CoS nanoparticles for a N-doped carbon framework, higher stability than commercial Pt/C system and greater catalytic activity towards ORR with an onset potential of about 0.921 V versus reversible hydrogen electrode (RHE) are observed. Furthermore, only a potential of 1.515 V versus RHE is required for achieving a current density of 10 mA cm−2.

Tailoring Blue-Green Double Emissions in Carbon Quantum Dots via Co-Doping Engineering by Competition Mechanism between Chlorine-Related States and Conjugated π-Domains.

Representing single-layer to tens of layers of graphene in a size less than 30 nm, carbon quantum dots (CQDs) is becoming an advanced multifunctional material for its unique optical, electronic, spin and photoelectric properties induced by the quantum confinement effect and edge effect. In present work, upon co-doping engineering, nitrogen and chlorine co-doped CQDs with uniquely strong blue-green double emissions are developed via a facile and one-pot hydrothermal method. The crystalline and optical properties of CQDs have been well manipulated by tuning the mole ratio of nitrogen/chlorine and the reaction time. The characteristic green emission centered at 512 nm has been verified, originating from the chlorine-related states, the other blue emissions centered at 460 nm are attributed to the conjugated π-domain. Increasing the proportion of 1,2,4-benzentriamine dihydrochloride can effectively adjust the bandgap of CQDs, mainly caused by the synergy and competition of chlorine-related states and the conjugated π-domain. Prolonging the reaction time promotes more nitrogen and chlorine dopants incorporate into CQDs, which inhibits the growth of CQDs to reduce the average size of CQDs down to 1.5 nm, so that the quantum confinement effect dominates into play. This work not only provides a candidate with excellent optical properties for heteroatoms-doped carbon materials but also benefits to stimulate the intensive studies for co-doped carbon with chlorine as one of new dopants paradigm.

Expanding Interlayer Spacing of Hard Carbon by Natural K+ Doping to Boost Na-Ion Storage.

Heteroatom-doped carbon is an attractive material for anodes in lithium-/sodium-ion batteries as a replacement for traditional graphite anodes. However, the complex fabrication process and high cost limit practical applications of these carbon materials. Here, we report a low-cost, natural potassium-doped carbon material, which is directly carbonized from the coconut endocarp-a kind of high potassium-containing biomass material. The obtained carbon structure features an expanded d(002)-spacing (0.4 nm) originating from the superhigh potassium content (6654 mg kg-1). Because of the improvement on charge transfer kinetics and electrical properties, the potassium-doped carbon anode exhibits promising electrochemical performance in sodium-ion batteries, including high initial reversible capacity (314 mAh g-1) and good cycle stability (289 mAh g-1 after 200 cycles). Additionally, this work opens up a new approach for the design of heteroatom-doped carbon materials from the viewpoint of being naturally environmental friendly.

Embellished hollow spherical catalyst boosting activity and durability for oxygen reduction reaction

Transition metals hybridized to heteroatom doped carbon material can be regarded as the most promising non-noble candidate for boosting the sluggish kinetics of oxygen reduction reaction (ORR). However, it has always been a challenge to vastly boost the activity, and simultaneously retain a favorable structure from the supporting material. Herein, we prepared a high surface area hollow spherical carbon as a supporting material, and employed aminothiophenol (ATI) and poly-aminothiophenol (PATI) as heteroatom precursors to synthesize nitrogen and sulfur co-doped catalysts, i.e. HCS-A and HCS-PA, respectively. The two catalysts possessed chemically similar surface composition, and nearly identical chemical states for each element. However, only HCS-A was able to vastly inherit both morphological advantage and high surface area from the carbon support. In further half-cell electrochemical testing, HCS-A performed better ORR activities and higher selectivity toward 4 electron pathway than HCS-PA in both acidic and alkaline media. Moreover, HCS-A was proven to have excellent durability in half-cell testing, methanol tolerance as well as outstanding peak power density in both fuel cells and zinc-air batteries. This work not only indicates the promising performances of HCS-A, but more importantly offers a new viewpoint on the selection of heteroatom precursor to retain a favorable structure.

N,S Co-Doped Carbon Nanofibers Derived from Bacterial Cellulose/Poly(Methylene blue) Hybrids: Efficient Electrocatalyst for Oxygen Reduction Reaction

Exploring inexpensive and highly efficient electrocatalyst to decrease the overpotential of oxygen reduction reaction (ORR) is one of the key issues for the commercialization of energy conversion and storage devices. Heteroatom-doped carbon materials have attracted increasing attention as promising electrocatalysts. Herein, we prepared a highly active electrocatalyst, nitrogen, sulfur co-doped carbon nanofibers (N/S-CNF), via in situ chemical oxidative polymerization of methylene blue on the bacterial cellulose nanofibers, followed by carbonization process. It was found that the type of nitrogen/sulfur source, methylene blue and poly(methylene blue), has significantly influence on the catalytic activity of the resultant carbon nanofibers. Benefiting from the porous structure and high surface area (729 m2/g) which favors mass transfer and exposing of active N and S atoms, the N/S-CNF displays high catalytic activity for the ORR in alkaline media with a half-wave potential of about 0.80 V, and better stability and stronger methanol tolerance than that of 20 wt % Pt/C, indicating great potential application in the field of alkaline fuel cell.

Heteroatom-doped porous carbon electrodes derived from a carbonyl-based aromatic porous polymer for supercapacitors

Two different heteroatom-doped microporous carbon materials, c-CBAP-N (nitrogen-doped) and c-CBAP-NS (nitrogen/sulfur co-doped), were prepared using a carbonyl-based aromatic porous polymer (CBAP) after amine-functionalization or chemical impregnation, followed by carbonization at 800 °C. The surface areas of c-CBAP-N and c-CBAP-NS were 1060 m2 g−1 and 1047 m2 g−1, respectively, which are predominantly microporous with a uniform pore size distribution centered at 0.4 nm. Their electrochemical performances as supercapacitors were measured by a three-electrode system using a 6 M KOH solution as the electrolyte. The specific capacitances of the c-CBAP-N and c-CBAP-NS electrodes were 203.2 F g−1 and 157.7 F g−1, respectively, as measured by galvanostatic discharge–charge analysis at a current density of 1 A g−1. Notably, these values are significantly higher than that of commercial activated carbon (130 F g−1 at 1 A g−1).

Nitrogen, phosphorus, and sulfur tri-doped hollow carbon shells derived from ZIF-67@poly (cyclotriphosphazene-co-4, 4′-sulfonyldiphenol) as a robust catalyst of peroxymonosulfate activation for degradation of bisphenol A

Heteroatom-doped carbon materials have emerged as attractive catalysts for peroxymonosulfate (PMS) activation and environment remediation recently due to its low cost and non-toxicity. In this study, novel N, P, and S tri-doped hollow carbon shells (NPSC) are elaborately fabricated using ZIF-67 and poly (cyclotriphosphazene–co-4,4′- sulfonyldiphenol) (PZS) as precursors. NPSC obtained at 700 °C shows better performance than those at other temperature (600 and 800 °C), and it can effectively degrade 90.1% of Bisphenol A (BPA) in the presence of PMS, which totally exceeds the performance of several common catalysts. It is found that for used catalyst, surface oxidation of carbon networks and blockage of heteroatom-doping active sites are two main reasons for the deterioration of reusability. Electron paramagnetic resonance (EPR) measurements and radical quenching tests are conducted to reveal that hydroxyl, sulfate, and superoxide radicals are main reactive species for BPA degradation in NPSC/PMS systems. Finally, it is proposed that synergistic effects of N, P, and S doping may greatly break the electroneutrality of pristine carbon structures, promote the O-O breakage of PMS, and facilitate the generation of radicals. Such findings dedicate to enlighten new thoughts and deeper understanding for synthesis of heteroatom-doped porous carbon in PMS activation.

Co NP/NC hollow nanoparticles derived from yolk-shell structured ZIFs@polydopamine as bifunctional electrocatalysts for water oxidation and oxygen reduction reactions

The pyrolysis under inert atmosphere has been widely used for the synthesis of metal containing heteroatoms doped carbon materials, versatile catalysts for various reactions. However, it is difficult to prevent metal nanoparticles aggregation during pyrolysis process. Herein, we reported the efficient synthesis of nitrogen doped carbon hollow nanospheres with cobalt nanoparticles (Co NP, ca. 10 nm in size) distributed uniformly in the shell via pyrolysis of yolk-shell structured Zn-Co-ZIFs@polydopamine (PDA). PDA acted as both protection layer and carbon source, which successfully prevented the aggregation of cobalt nanoparticles during high-temperature pyrolysis process. The Co NP and N containing carbon (Co NP/NC) hollow nanospheres were active for both oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), affording overpotential of 430 mV at 10 mA/cm2 for OER in 1 M KOH and comparable half-wave potential to that of Pt/C (0.80 V vs RHE) for ORR in 0.1 M KOH. The superior performance of carbon hollow nanospheres for both OER and ORR was mainly attributed to its small metal nanoparticles, N-doping and hollow nanostructure. The protection and confinement effect that originated from PDA coating strategy could be extended to the synthesis of other hollow structured carbon materials, especially the ones with small metal nanoparticles.

Highly Efficient Vitamin-B12 Pyrolyzed N-Co-C Electrocatalyst for Hydrogen Evolution Reaction

Water splitting by electrocatalysis into hydrogen via the hydrogen evolution reaction (HER) offers a promising solution for green renewable energy generation1. In past several years, Pt and Pt based nanomaterials are the mostly served as an efficient electrocatalyst for HER; however, due to high-cost and low abundancy of Pt limits its vast utility for the commercial HER application. Therefore, it's highly needed to develop nonprecious metal based electrocatalyst for HER towards cost effective commercial application2. Over the past decades, tremendous efforts have been made for replacing the Pt based electrocatalysts for HER. Recent advances in carbon nanomaterials (RGO, CNT, etc.,) have shown their promising future in energy-related electrocatalytic reactions, such as ORR, OER, and HER. After heteroatom (such as N, B, P, and S) doping, the enhanced catalysis activity of carbon nanomaterials has been widely illustrated for ORR. Among all the reported electrocatalysts, the co-doping of trace transition metals on heteroatoms doped carbon materials leads to form metal complexes (Ex. Co-Nx), showing promising HER activity in the aqueous electrolyte. In addition, the reported density functional theory (DFT) simulation shows that when combining both coordinations into one complex, the optimized charge distribution results in an ideal value of ΔGH in Metal-Carbon-Nitrogen (M-C-N) hybrid system and which is much better than the single or mixture system of M-C and M-N3. In this presentation, we will demonstrate a new HER electrocatalyst based on N-Co-C system. The N-Co-C catalysts are prepared by a one-step pyrolysis process at the high temperature in which vitamin-B12 used as a metal precursor together with reduced graphene oxide (RGO). We observed that the electrocatalytic activities of N-Co-C catalysts are strongly related with the pyrolysis temperature and metal loading. The N-Co-C catalyst pyrolyzed at 800oC showed the highest HER activity with lowest overpotential of 110 mV at a current density of 10 mA cm-2. It shows the optimum Tafel slope of 65 mV decade-1 and excellent stability over 20 h in acidic condition. The as synthesized catalyst was characterized by XRD, XPS and XAS. The results indicate that Co-corrin complexes (Vitamin B12) together with RGO have been decomposed at the high temperature to form N-Co-C structure. This conjugation induces that, downshift of the d-band center of cobalt, and thereby decreases its hydrogen binding energy. This, in turn, favors the electrochemical desorption of Hads and leads to a relatively moderate Co−H binding strength, resulting in the enhancement of the hydrogen evolution reaction. The comparison of HER activity and stability of N-Co-C electrocatalyst in alkaline electrolytes will be discussed at the meeting.