Individual Graphene Sheets Research Articles

Structure-property relationships in the electrical conductivity of multilayer graphene sheet/epoxy nanocomposites

The relationship between the physicochemical properties of multilayer graphene sheets (GSs), their resulting state of dispersion, and the effective electrical conductivity of GS/epoxy nanocomposites is investigated. To construct such relationship, four types of GSs with dissimilar properties were physicochemically, structurally, and morphologically characterized, and correlated with the direct current and alternating current (AC) electrical responses of their polymeric nanocomposites. It was found that the most influential parameters that affect the electrical conductivity of the nanocomposites are the size and density of agglomerates formed at the mesoscale. Both parameters, in turn, are governed by the physicochemical properties of the individual GSs. At the nanostructure level, the lateral size of the GS arises as the most influential parameter, with larger GSs yielding higher conductivities and lower percolation thresholds. The carbon/oxygen ratio of the GSs also showed moderate influence. The nanocomposites showed a resistive (R)-capacitive (C) electrical response in AC, which fits to a two-element parallel RC model. Both, the power law and general effective media (GEM) models predict similar percolation thresholds, but the GEM model is more general and adequately reproduces the whole electrical curve for all filler concentrations.

Investigation of microstructure, surface roughness and thermo-stability of reduced graphene synthesized in an aqueous piranha solution via electrochemical method

An applied voltage induces ionic species to intercalate into graphite, where they generate gaseous species that expand and exfoliate individual graphene sheets. Electrochemical exfoliation is a promising bulk process for creating graphene from graphite. In this study, a bulk graphene nano material is electrochemically produced in an aqueous solution of piranha solution. The process is carried out in an enclosed environment to reduce the flaws and structural disabilities. Throughout the process of exfoliation, a potential of 24 V DC has been supplied at a modest level for a certain period of time. As an electrolyte, a combination of sulphuric acid and hydrogen peroxide in the proportion of 6:2 has been utilised. The preoxidized graphite that is acquired by oxidation is then subjected to a thermal reduction process at a temperature of 550 °C for a duration of three hours.The microstructure of thermally reduced graphene oxide (T-rGO) is analysed with field emission scanning electron microscopy (FESEM), the maximum surface roughness found to be 1.57 nm on an angstrom-scale level, it is able to determine the surface roughness of samples and total weight loss has been occurred at around 60 % between the temperature range of 600–900 °C.

Doped graphene characterized via Raman spectroscopy and magneto-transport measurements

Functionalizing graphene beyond its intrinsic properties has been a key concept since the first successful realization of this archetype monolayer system. While various concepts, such as doping, co-doping, and layered device design, have been proposed, the often complex structural and electronic changes are often jeopardizing simple functionalization attempts. Here, we present a thorough analysis of the structural and electronic properties of co-doped graphene via Raman spectroscopy as well as magneto-transport and Hall measurements. The results highlight the challenges in understanding its microscopic properties beyond the simple preparation of such devices. It is discussed how co-doping with N and B dopants leads to effective charge-neutral defects acting as short-range scatterers, while charged defects introduce more long-range scattering centers. Such distinct behavior may obscure or alter the desired structural as well as electronic properties not anticipated initially. Exploring further the preparation of effective pn-junctions, we highlight step by step how the preparation process may lead to alterations in the intrinsic properties of the individual layers. Importantly, it is highlighted in all steps how the inhomogeneities across individual graphene sheets may challenge simple interpretations of individual measurements.

Graphene oxide obtention via liquid phase exfoliation from high-rank coal: A comparison of mineral matter removal by alkaline bath

Colombia is one of the world's leading exporters of coal and coke, with significant reserves of high-quality coal. Most of the coal exported from Colombia is used for power generation, but there is also a class of coal that is suitable for making coke. Coke is a raw material required for making steel, and it is produced by heating coal to high temperatures in the absence of air. Colombia is the third-largest global exporter of coke, with a significant portion of its exports going to the steel industry in countries such as Brazil, Mexico, and the United States. The country's high-quality coal reserves and proximity to major markets make it an important player in the global coal and coke trade. On the other hand, graphene and its derivative Graphene Oxide (GO) have unique properties that make them suitable for a wide range of commercial applications. Graphene has exceptional mechanical strength and high electrical conductivity, which make it an attractive material for a variety of electronic and structural applications. For example, graphene-based materials are being developed for use in flexible electronic devices, sensors, and high-strength composites. GO, on the other hand, is highly resistive but still retains exceptional mechanical strength. This makes it useful in applications where electrical conductivity is not necessary but mechanical strength and durability are important. Graphene production using current techniques can be expensive and inefficient, which limits its widespread adoption for commercial applications. However, new production methods, such as Liquid Phase Exfoliation (LPE), are being developed to address these challenges. LPE is a method for producing graphene and graphene oxide that involves using a liquid solvent to break apart graphite into individual graphene sheets. This method is more efficient and cost-effective than traditional methods such as mechanical exfoliation and chemical vapor deposition. In recent years, there has been increasing interest in using high-rank coal from Colombia as a raw material for graphene production using LPE. This is because high-rank coal from Colombia is known to have a high carbon content and low impurity levels, which makes it an ideal raw material for graphene production. Researchers have successfully produced GO using the LPE method and high-rank coal from Boavita, Colombia. This has the potential to significantly increase the supply of graphene and graphene oxide, making it more accessible for commercial applications. Additionally, using coal as a raw material for graphene production has the potential to create a new market for coal, which could benefit the Colombianeconomy. In order to synthesize GO, it is important to establish a suitable protocol for the grinding procedure and particle size selection. (i. more than 0.15 mm, ii. 0.15 mm to 0.05 mm, and iii. less than 0.05 mm) were defined. To compare the yield, the mineral matter removal procedure was carried out with a basic leaching bath. Coal oxidation was performed using the modified Hummers process, and GO was then obtained using LPE. This method has the following advantages:•It is feasible to produce GO from high-rank coal with acceptable quality and particulate size smaller than 0.15 mm, yields that are close to 5%, and flakes with fewer than 15 layers.•This approach also could eliminate dependence on graphite as the carbon feedstock for graphene production.•It is an alternative to manufacture GO from coal dust collected from mines.

Determination of Paracetamol on Electrochemically Reduced Graphene Oxide-Antimony Nanocomposite Modified Pencil Graphite Electrode Using Adsorptive Stripping Differential Pulse Voltammetry.

A simple, highly sensitive, accurate, and low-cost electrochemical sensor was developed for the determination of over-the-counter painkiller, paracetamol (PC). The enhanced sensing capabilities of the developed sensor were fabricated by the single-step modification of disposable pencil graphite electrodes (PGEs) with the simultaneous electrochemical reduction in graphene oxide and antimony (II) salts. For this purpose, an electrochemically reduced graphene oxide–antimony nanoparticle (ERGO-SbNP) nanocomposite material was prepared by trapping metallic nanoparticles between individual graphene sheets in the modification of PGEs. Structural characterization by FTIR and Raman spectroscopy was employed to confirm the presence of oxygen functional groups and defects in the conjugated carbon-based structure of GO. Morphological differences between the modified PGEs were confirmed by HRTEM and HRSEM for the presence of nanoparticles. The modified electrodes were further electrochemically characterized using CV and EIS. The electrooxidation of PC on an ERGO-SbNPs-PGE was achieved by adsorptive stripping differential pulse voltametric analysis in 0.1 mol·L−1 phosphate buffer solution at pH = 7.0. The optimum current response was used to record a detection limit of 0.057 µmol·L−1 for PC. The electrochemical sensor was further used in real sample analysis for a commercially available pharmaceutical tablet (500 mg PC), for which the percentage recovery was between 99.4% and 100.8%.

Macroporous Graphene Frameworks for Sensing and Supercapacitor Applications

Abstract3D architectures based on graphene have triggered a great deal of interest in energy, sensing, and environmental applications. This work describes, a simple electrochemical approach for the direct deposition of a functionalized graphene framework by utilizing electrostatic interactions between graphene oxide (GO) and a cationic surfactant. The surfactant improves the adsorption of GO sheets on the electrode surface, allowing the integration of individual graphene sheets into 3D structures with large electrochemically active surface area. Without using binders or conductive additives, the current approach leads to supercapacitors with high specific capacitance (320 F g−1) and areal capacitance (≈400 mF cm−2 for two electrode cells with single‐sided coatings), which compares favorably to commercial activated carbon supercapacitors. Moreover, the supercapacitors demonstrate low internal resistance (≈1 Ω cm−2), excellent cycling stability (no loss observed after 10 000 cycles) while also maintaining superior rate capability. In another application, these frameworks were successfully implemented as an electrochemical sensor for the simultaneous determination of small biomolecules including ascorbic acid, dopamine and uric acid with high sensitivity, selectivity and reproducibility. This work provides a simple, yet effective, strategy for the fabrication of macroporous electrodes with superior chemical, structural, and electrical properties that are desirable for a broad range of applications.

Topological edge modes and localization transition in quasiperiodic graphene multilayer arrays

By using rational and irrational on-site modulation in graphene waveguide arrays, we construct both commensurate and incommensurate Aubry-André-Harper (AAH) models and achieve the topological edge states and localization transition for graphene surface plasmon polaritons (SPPs). We show that when the commensurate AAH graphene array is truncated, topological edge states emerge, which are immune to the random perturbation of modulation depth in each individual graphene sheet. While for an incommensurate AAH array, localization transition for SPPs modes have also been achieved when the modulation depth reaches a critical value. Our work points out that graphene waveguide array provides a promising platform for robust light transport and compact localization within a fully deep subwavelength scale.

Controllable assembly of continuous hollow graphene fibers with robust mechanical performance and multifunctionalities

Macroscopic conformation of individual graphene sheets serves as the backbone of translating their intrinsic merits towards multifunctional practical applications. However, controllable and continuous assemblies of graphene-based nanomaterials to create stable macroscopic structural components are always in face of great challenge. We have developed a scalable converging-flow assisted wet-spinning methodology for continuously fabricating hollow graphene fibers (HGFs, the newest variation of solid graphene fibers) with high quality. The degradable silk thread is selectively utilized as the continuous hollow structure former that holds the coaxially stacked graphene sheets aligned through the converging-flow modulating process. For the first time, we have created the longest freestanding HGF in length of 2.1 m. The continuous HGFs are in an average diameter of 180 μm and with 4–8 μm adjustable wall thicknesses. The optimal HGF demonstrates an average tensile strength of 300 MPa and modulus of 2.49 GPa (comparable to typical solid graphene fibers, but the highest among the reported HGFs in literature) and an exceptional failure elongation of 10.8%. Additionally, our continuous HGFs exhibit spontaneous resistive response to thermal and strain stimuli (in form of large deformations and human motions), offering great potential for developing multifunctional sensors. We envision that this work demonstrates an effective and well-controlled macroscopic assembly methodology for the scaled-up mass production of HGFs.

Plasmonic characteristics of the structure with double graphene layers immersed in chiral media and applications in detection of chirality.

The propagating behavior of surface plasmons in chiral media is different from that in achiral media. By comparing the propagation behavior of SPPs, the chirality of the environment can be evaluated. We theoretically reveal the features of SPPs in a structure with two individual graphene sheets surrounded by chiral environment. A more universal dispersion relation covering the achiral cases is obtained. The effects of the chirality of medium and the chemical potential of graphene on the SPPs are explored. Besides, a novel method of detecting the chirality of the environment based on the lateral optical force and torque is proposed. The characteristics of the structure may enrich the surface plasmonic wave theory on the waveguides with multiple graphene sheets and provide new opportunities for the design of more compact nanophotonic functional devices and novel biosensors.

Ultralight, Ultraflexible, Anisotropic, Highly Thermally Conductive Graphene Aerogel Films.

Graphene aerogels have attracted much attention as a promising material for various applications. The unusually high intrinsic thermal conductivity of individual graphene sheets makes an obvious contrast with the thermal insulating performance of assembled 3D graphene materials. We report the preparation of anisotropy 3D graphene aerogel films (GAFs) made from tightly packed graphene films using a thermal expansion method. GAFs with different thicknesses and an ultimate low density of 4.19 mg cm−3 were obtained. GAFs show high anisotropy on average cross-plane thermal conductivity (K⊥) and average in-plane thermal conductivity (K||). Additionally, uniaxially compressed GAFs performed a large elongation of 11.76% due to the Z-shape folding of graphene layers. Our results reveal the ultralight, ultraflexible, highly thermally conductive, anisotropy GAFs, as well as the fundamental evolution of macroscopic assembled graphene materials at elevated temperature.

Terahertz hybrid plasmonic waveguides with ultra-long propagation lengths based on multilayer graphene-dielectric stacks.

To develop on-chip photonic devices capable of transmitting terahertz signals beyond the propagation distance of millimeter while keeping deep subwavelength field confinement has been a challenging task. Herein, we propose a novel multilayer graphene-based hybrid plasmonic waveguide (MLGHPW) consisting of a cylindrical dielectric waveguide and hyperbolic metamaterials. The device is based on alternating graphene and dielectric layers on a rib substrate, operating in the terahertz range (f = 3 THz). We couple the fundamental dielectric waveguide mode with the fundamental volume plasmon polarition modes originated from the coupling of plasmon polaritons at individual graphene sheets. The resulting hybrid mode shows ultra-low loss compared with the conventional GHPW modes at the comparable mode sizes. The present MLGHPW demonstrated a few millimeters of propagation length while keeping the mode area of 10-3A0, where A0 is the diffraction-limited area, thus possessing a thirty times larger figure of merit (FoM) compared to other GHPWs. The additional degree of freedom (the number of graphene layers) makes the proposed MLGHPW more flexible to control the mode properties. We investigated the geometry and physical parameters of the device and identified optimal FoM. Moreover, we analyzed the crosstalk between waveguides and confirmed the potential to construct compact on-chip terahertz devices. The present design might have the possible extensibility to other graphene-like materials, like silicene, germanen, stanene etc.

Ultra-Low-Loss Mid-Infrared Plasmonic Waveguides Based on Multilayer Graphene Metamaterials.

Manipulating optical signals in the mid-infrared (mid-IR) range is a highly desired task for applications in chemical sensing, thermal imaging, and subwavelength optical waveguiding. To guide highly confined mid-IR light in photonic chips, graphene-based plasmonics capable of breaking the optical diffraction limit offer a promising solution. However, the propagation lengths of these materials are, to date, limited to approximately 10 µm at the working frequency f = 20 THz. In this study, we proposed a waveguide structure consisting of multilayer graphene metamaterials (MLGMTs). The MLGMTs support the fundamental volume plasmon polariton mode by coupling plasmon polaritons at individual graphene sheets over a silicon nano-rib structure. Benefiting from the high conductivity of the MLGMTs, the guided mode shows ultralow loss compared with that of conventional graphene-based plasmonic waveguides at comparable mode sizes. The proposed design demonstrated propagation lengths of approximately 20 µm (four times the current limitations) at an extremely tight mode area of 10−6 A0, where A0 is the diffraction-limited mode area. The dependence of modal characteristics on geometry and material parameters are investigated in detail to identify optimal device performance. Moreover, fabrication imperfections are also addressed to evaluate the robustness of the proposed structure. Moreover, the crosstalk between two adjacent present waveguides is also investigated to demonstrate the high mode confinement to realize high-density on-chip devices. The present design offers a potential waveguiding approach for building tunable and large-area photonic integrated circuits.

Significant Capacitance Enhancement via In Situ Exfoliation of Quasi-One-Dimensional Graphene Nanostripes in Supercapacitor Electrodes

Graphene has received much attention as a supercapacitor electrode material due to its chemical inertness in preventing reaction with electrolytes and the large surface area due to its two-dimensional nature. However, when graphene sheets are processed into electrodes, they tend to stack together and form a turbostratic graphite material with a much reduced surface area relative to the total surface area of individual graphene sheets. Separately, electrochemical exfoliation of graphite is one method of producing single-layer graphene, which is often used to produce graphene for supercapacitor electrodes, although such exfoliated graphene still leads to reduced surface areas due to stacking during electrode fabrication. To utilize the large surface area of graphene, graphene must be exfoliated in situ within a supercapacitor device after the device fabrication. However, graphitic electrodes are typically destroyed upon exfoliation, which is largely due to the loss of electrical connectivity among small exfoliated graphene flakes. Here, we report successful in situ exfoliation of graphene nanostripes, a type of quasi-one-dimensional graphene nanomaterial with large length-to-width aspect ratios, as the anode material in supercapacitors. We find that the in situ exfoliation leads to over 400% enhancement in capacitance as the result of retaining the electrical connectivity among exfoliated quasi-one-dimensional graphene nanostripes in addition to increasing the total surface area, paving ways to fully realizing the benefit of graphene electrodes in supercapacitor applications.

Unexpected electocatalytic activity of a micron-sized carbon sphere-graphene (MS-GR) supported palladium composite catalyst for ethanol oxidation reaction (EOR)

For the first time, a hybrid carbon material consisting of micron-sized carbon spheres and graphene (denoted as MS-GR) was prepared via a hydrothermal method. In this work, micron-sized carbon spheres were prepared using glucose and 1-butyl-3-methylimidazolium tetrafluoroborate as the starting materials through a hydrothermal method, and graphene was employed as purchased. One-pot and two-step hydrothermal methods were respectively employed to prepare MS-GR, and in each preparation method, three different amounts of graphene were added in the preparation system while maintaining the added amounts of other reagents identical for each prepared catalyst. As a result, six kinds of hybrid carbon materials were fabricated in this work. Next, MS-GR supported palladium composite catalysts were fabricated through a hydrothermal method using PdO·H2O as the palladium source. Metallic Pd particles, metallic Pd particles along with PdO were indicated by XRD patterns to be the main substances of the one-pot and two-step hydrothermally prepared MS-GR supported catalysts, respectively. As presented by the SEM images, micron-sized carbon spheres and individual graphene sheets as well as the small particles were exhibited clearly in all prepared catalysts, suggesting that all the resultant catalysts were a composite material. Most importantly, as indicated by the CV and CA curves, all synthesized catalysts showed obvious electrocatalytic activities for EOR. In particular, the peak current density of peak f for EOR in the CV curves on catalyst t-4 was as high as 29.1 mA cm-2, significantly larger than the previously reported values. And the current density of EOR measured by CA test on catalyst t-4 was retained as high as 2.83 mA cm-2 after 600 s, showing an excellent electrocatalytic durability. In this work, a carbon material constructed by micron-sized carbon spheres and graphene as well as a novel MS-GR supported Pd catalyst was developed for the first time, which was very helpful to the final commercialization of a Pd-based EOR electrocatalyst due to the greatly reduced the preparation cost and the facile preparation procedure.

Highly Crystalline Graphene Fibers with Superior Strength and Conductivities by Plasticization Spinning

AbstractGraphene fiber (GF), a macroscopic one‐dimensional assembly of individual graphene sheets, promises both extraordinary mechanical performance and superior multifunctionality. However, the properties of graphene fiber are still limited due to the unfavorable crystalline structures, especially induced by wrinkled conformations of graphene. A plasticization spinning strategy is presented to achieve GF with both high mechanical strength and electrical/thermal conductivity. Adjusting the interlayer space from 1.2 to 1.8 nm by intercalating proper plasticizers to adjacent graphene oxide sheets enables graphene oxide fibers to achieve a 580% enhanced deformable plasticity. Such a plasticization spinning flattens random graphene wrinkles, and regulates sheets with high order and stacking density, thereby forming large crystallite domains. The GF exhibits all around record performance including mechanical strength (3.4 GPa), electrical conductivity (1.19 × 106 S m−1), and thermal conductivity (1480 W m−1 K−1). The optimally crystalline GF with the integration of benchmark overall properties and scalable fabrication is likely to be attractive and competitive in future industrial applications.

Electrolyte gating in graphene-based supercapacitors and its use for probing nanoconfined charging dynamics.

Graphene-based nanoporous materials have been extensively explored as high-capacity ion electrosorption electrodes for supercapacitors. However, little attention has been paid to exploiting the interactions between electrons that reside in the graphene lattice and the ions adsorbed between the individual graphene sheets. Here we report that the electronic conductance of a multilayered reduced graphene oxide membrane, when used as a supercapacitor electrode, can be modulated by the ionic charging state of the membrane, which gives rise to a collective electrolyte gating effect. This gating effect provides an in-operando approach for probing the charging dynamics of supercapacitors electrically. Using this approach, we observed a pore-size-dependent ionic hysteresis or memory effect in reduced graphene oxide membranes when the interlayer distance is comparable to the ion diameter. Our results may stimulate the design of novel devices based on the ion-electron interactions under nanoconfinement.

Self-Planarization of High-Performance Graphene Liquid Crystalline Fibers by Hydration.

Graphene fibers (GFs) are promising elements for flexible conductors and energy storage devices, while translating the extraordinary properties of individual graphene sheets into the macroscopically assembled 1D structures. We report that a small amount of water addition to the graphene oxide (GO) N-methyl-2-pyrrolidone (NMP) dispersion has significant influences on the mesophase structures and physical properties of wet-spun GFs. Notably, 2 wt % of water successfully hydrates GO flakes in NMP dope to form a stable graphene oxide liquid crystal (GOLC) phase. Furthermore, 4 wt % of water addition causes spontaneous planarization of wet-spun GFs. Motivated from these interesting findings, we develop highly electroconductive and mechanically strong flat GFs by introducing highly crystalline electrochemically exfoliated graphene (EG) in the wet-spinning of NMP-based GOLC fibers. The resultant high-performance hybrid GFs can be sewn on cloth, taking advantage of the mechanical robustness and high flexibility.

Correction to "Defect-Driven Heterogeneous Electron Transfer between an Individual Graphene Sheet and Electrode".

RETURN TO ISSUEPREVAddition/CorrectionNEXTORIGINAL ARTICLEThis notice is a correctionCorrection to “Defect-Driven Heterogeneous Electron Transfer between an Individual Graphene Sheet and Electrode”Yi XiaoYi XiaoMore by Yi Xiao, Yi SuYi SuMore by Yi Su, Xiaodong LiuXiaodong LiuMore by Xiaodong Liu, and Weilin Xu*Weilin XuMore by Weilin Xuhttp://orcid.org/0000-0001-7140-8060Cite this: J. Phys. Chem. Lett. 2020, 11, 11, 4421Publication Date (Web):May 21, 2020Publication History Published online21 May 2020Published inissue 4 June 2020https://doi.org/10.1021/acs.jpclett.0c01336Copyright © 2020 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views349Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (449 KB) Get e-Alerts Get e-Alerts

A highly stretchable, super-hydrophobic strain sensor based on polydopamine and graphene reinforced nanofiber composite for human motion monitoring

Much attention has been given to flexible electronic devices in recent years. Conductive polymer composites (CPCs) have been utilized to fabricate strain sensors owing to their lightweight and high flexibility. It is a great challenge to develop flexible and wearable strain sensors with light weight, good skin affinity and gas permeability, high sensitivity and excellent corrosion resistance. In this work, electrospun thermoplastic polyurethane (TPU) nanofibers were first decorated by graphene through ultra-sonication, followed by polydopamine (PDA) modification and then hydrophobic treatment with 1H, 1H, 2H, 2H-perfluorodecanethiol (PFDT). The obtained electrical conductive polymer nanofiber composites (CPNCs) have a hierarchical polymer core/graphene shell structure and exhibit super-hydrophobicity even under harsh environments. The introduction of PDA not only improves the interfacial interaction between individual graphene sheets but also the interaction between graphene and the TPU nanofibers. Their mechanical properties including Young's modulus, tensile strength and elongation at break are significantly improved, compared to those of TPU nano-fibrous membranes. When CPNC is used as a strain sensor, it displays high stretchability, controllable sensitivity, excellent cyclical stability and durability. Hence, the nanofiber composite based strain sensor can be attached on the skin for precise monitoring of different human motions, such as tiny and large body movements and thus has promising applications in wearable devices.

Environmentally stable macroscopic graphene films with specific electrical conductivity exceeding metals

Air stable, lightweight, and electrically conductive carbon-based films are highly desired for flexible electronic devices and products. Graphene film, a macroscopic assembly of individual graphene sheets, holds great potential to replace conventional brittle pyrolytic carbon film due to the excellent electrical transport property and flexibility. However, the electrical conductivity of graphene film is still inferior to metallic conductors, usually unstable in air as doped. We chose metal chloride (MoCl5) as air stable dopant and fabricated doped graphene film with well-controlled intercalation structure. The MoCl5 modified graphene film shows record high electrical conductivity of 1.73 × 107 S m−1, record high mobility of 2190.47 cm2 V−1 s−1, remarkable specific electrical conductivity exceeding benchmark metals (e.g., Au, Ag, Cu), and ultralow temperature coefficient of resistance (1.4 × 10−4 K−1). Importantly, the electrical conductivity and overall structure of MoCl5 intercalated films are exceptional stable in atmospheric environment, enabling wide applications in electronic devices, electromagnetic interference, and energy storage.