Nitrogen-doped Reduced Graphene Oxide Research Articles

Atomic-Level Insights into Defect-Driven Nitrogen Doping of Reduced Graphene Oxide

Nitrogen-doped graphene has been increasingly utilized in a variety of energy-related applications, serving as a catalyst or support material for fuel cells, and as an anode material for lithium-ion batteries, among others. The thermal reduction of graphene oxide (GO) in nitrogenous sources to incorporate nitrogen, producing nitrogen-doped reduced graphene oxide (NRGO), is the most favored method. Controlling atomic configurations of nitrogen-doped sites is the key factor for tailoring the physico-chemical properties of NRGO, but major challenges remain in identifying detailed atomic arrangements at nitrogen binding sites on highly defective and chemically functionalized GO surfaces. In this paper, we present atomistic-scale modeling of the nitrogen doping process of GO with different types of vacancy defects. Molecular dynamics simulations using a reactive force field indicate that the edge carbon atoms on defect sites are the dominant initiation location for nitrogen doping. Further, first-principles calculations using density functional theory present energetically favorable chemical transition pathways for nitrogen doping. The significance of this work lies in providing important chemical insights for the effective control of the desired properties of NRGO by suggesting a detailed mechanism of the nitrogen doping process of GO.

Electrochemical performance of ZnxCo3-xO4/N-doped rGO nanocomposites for energy storage application

In this study, nanocomposites consisting of zinc-doped cobalt oxides with a spinel structure and nitrogen-doped reduced graphene oxide (ZnxCo3-xO4 (x=0 and 1))/N-doped rGO) were synthesized using a solvothermal method. The synthesized materials were investigated using XRD, TEM, EDS, BET, Raman, and XPS for their phase formation, morphology, elemental composition, surface area, and chemical states. XRD analysis revealed that the metal oxides (Co3O4 and ZnCo2O4) present in the composites exhibited a single-phase cubic spinel structure, with a nanocrystalline nature and crystallite size ranging from 8 nm to 20 nm. Raman and TEM analyses revealed the co-existence of metal oxide nanoparticles and N-doped rGO phases in the composites. Electrodes were fabricated using the synthesized nanocomposite materials and subjected to electrochemical testing, including CV, GCD and EIS. The specific capacitiance (Cs) of samples determined to be 181 F/g and 234 F/g for CO/NrGO (Co3O4/N-doped rGO) and ZCO/NrGO (ZnCo2O4/N-doped rGO) nanocomposites, respectively, at lower current density (0.5 A/g). At all current densities, the CS of ZCO/NrGO nanocomposite electrode is observed to be higher than the CO/NrGO nanocomposite, probably due to structural defects and uniform anchoring of ZnCo2O4 particles over the layers of NrGO. The ZCO/NrGO composite electrode exhibits ∽86% capacitance retention after 3000 cycles.

The impact of nitrogen-doped reduced graphene oxide reinforcement on the thermal and mechanical properties of CFRP

This study used experimental methods to investigate the impact of nitrogen-doped reduced graphene oxide particles (ND-RGOP) reinforcement on thermal and mechanical properties of unidirectional carbon fiber/ epoxy composites (CFRP). In the results, storage modulus and loss modulus significantly increase with the ND-RGOP addition. Besides, glass transition temperature is enhanced with the addition of 0.4 wt% ND-RGOP. In tensile mode, when compared to the baseline (0 weight% ND-RGOP) composites, the elastic modulus in the 0° direction (E1) enhanced by 8.25 % and 11.39 % with 0.4 (0.4 weight%) and 0.8 (0.8 weight%) ND-RGOP addition, respectively. Besides, the ultimate tensile strength of the 0.4 ND-RGOP/CFRP composites significantly reduced by 16.33 % and 53.08 % in both 0° and 90° directions, respectively, as a result of the fracture mechanism changing from fiber pull out and fiber cracking to fiber breakage which was confirmed by SEM investigations. Furthermore, both the compressive modulus and the shear modulus increased with ND-RGOP reinforcement over 10 %, although the ultimate compressive strength decreases with low ND-RGOP reinforcement. In conclusion, low concentrations of ND-RGOP addition improves the thermal and mechanical properties of CFRP laminates in elastic region, although high concentrations of ND-RGOP decreases the thermal properties.

Nitrogen-doped reduced graphene oxide (N-rGO) three-dimensional electrode electrochemically activates persulfate for the degradation of tetracycline

Nitrogen-doped reduced graphene oxide (N-rGO) three-dimensional electrode electrochemically activates persulfate for the degradation of tetracycline

Effect of nitrogen-doped reduced graphene oxide on the wave-absorbing properties of hollow ZnFe2O4

Effect of nitrogen-doped reduced graphene oxide on the wave-absorbing properties of hollow ZnFe2O4

Redox-Active Phenanthrenequinone Molecules and Nitrogen-Doped Reduced Graphene Oxide as Active Material Composites for Supercapacitor Applications.

Carbon-based supercapacitor electrodes are generally restricted in energy density, as they rely exclusively on electric double-layer capacitance (EDLC). The introduction of redox-active organic molecules to obtain pseudocapacitance is a promising route to develop electrode materials with improved energy densities. In this work, we develop a porous nitrogen-doped reduced graphene oxide and 9,10-phenanthrenequinone composite (N-HtrGO/PQ) via a facile one-step physical adsorption method. The electrochemical evaluation of N-HtrGO/PQ using cyclic voltammetry showed a high capacitance of 605 F g-1 in 1 M H2SO4 when the composite consisted of 30% 9,10-phenanthrenequinone and 70% N-HtrGO. The measured capacitance significantly exceeded pure N-HtrGO without the addition of redox-active molecules (257 F g-1). In addition to promising capacitance, the N-HtrGO/30PQ composite showed a capacitance retention of 94.9% following 20,000 charge/discharge cycles. Based on Fourier transform infrared spectroscopy, we postulate that the strong π-π interaction between PQ molecules and the N-HtrGO substrate enhances the specific capacitance of the composite by shortening pathways for electron transfer while improving structural stability.

Hierarchical and Nanocrystallite-Assembled Ultraporous NiO/MnCo2O4 for All Solid-State Hybrid Supercapacitors with Robust Energy Efficiency and Extended Operational Durability.

To address the growing demand of highly Ragone efficient electrochemical energy storage devices, we have innovated a synthetic design strategy and employed a tartrate-mediated kinetic precipitation process to fabricate an ultraporous ribbon-like hierarchical microstructure of Ni-, Mn-, and Co-based ternary oxide, i.e., NiO/MnCo2O4, and employed it as a battery-type positive electrode material to assemble an ASSHSC (all-solid-state hybrid supercapacitor) device with nitrogen-doped reduced graphene oxide (N-rGO) as the positive electrode material. NiO/MnCo2O4 exhibits distinct crystallographic phase, near-perfect elemental stoichiometry, evident bulk porosity, and rich nanocrystallite assembly in the randomly arranged microstructure of near-uniform size and shape. Thorough electrochemical studies corroborate that the battery-type NiO/MnCo2O4 exhibits remarkable electrochemical reversibility during charge transfer, high efficiency in supercapacitive charge storage, low charge transfer, series and diffusion resistance. The NiO/MnCo2O4||N-rGO ASSHSC device assembled with the PVA-KOH film as the separator electrolyte offers rich charge storage physiognomies, which accentuates excellent electromicrostructural compatibility between the electrode materials in the device. The NiO/MnCo2O4||N-rGO ASSHSC device shows low charge transfer and diffusion resistance, and it also delivers high mass and areal specific capacitance/capacity, energy and power density, Ragone efficiency (∼131 Wh kg-1 at ∼2134 W kg-1 and ∼31 Wh kg-1 at ∼5005 W kg-1), and extended operational durability (98.2% specific capacitance retention after 12,000 successive GCD cycles) under high-rate working conditions. The present optimized approach to design highly efficient multiple transition-metal-based oxides as battery-type electrode materials and fabricate rich Ragone-efficient ASSHSC devices can be widely adopted in the future development of high-performance hybrid supercapacitors, which may be largely integrated in various pioneering technologies.

Waste plastic derived nitrogen-doped reduced graphene oxide decorated core–shell nano-structured metal catalyst (WpNrGO-Pd–Ru) for a proton exchange membrane fuel cell

Graphical representation of the WpNrGO_Pd_Ru nano-structured metal catalyst.

Evolution of High-Index Facets Pt Nanocrystals Induced by N-Defective Sites in the Integrated Electrode for Enhanced Methanol Oxidation.

Highly efficient and durable Pt electrocatalysts are the key to boost the performance of fuel cells. The high-index facets (HIF) Pt nanocrystals are regarded as excellent catalytic activity and stability catalysts. However, nucleation, growth and evolution of high-index facets Pt nanocrystals induced by defective sites is still a challenge. In this work, tetrahexahedron (THH) and hexactahedron (HOH) Pt nanocrystals are synthesized, which are loaded on the nitrogen-doped reduced graphene oxide (N-rGO) support of the integrated electrodes by the square wave pulse method. Experimental investigations and density functional theory (DFT) calculations are conducted to analyze the growth and evolution mechanism of HIF Pt nanocrystals on the graphene-derived carbon supports. It shows that the H adsorption on the N-rGO/CFP support can induce evolution of Pt nanocrystals. Moreover, the N-defective sites on the surface of N-rGO can lead to a slower growth of Pt nanocrystals than that on the surface of reduced graphene oxide (rGO). Pt/N-rGO/CFP (20min) shows the highest specific activity in methanol oxidation, which is 1.5 times higher than that of commercial Pt/C. This research paves the way on the design and synthesis of HIF Pt nanocrystal using graphene-derived carbon materials as substrates in the future.

Nanostructured Fe-N-C Electrocatalysts with CeO2 Additives for PEM Fuel Cells

The development of cost-effective electrocatalysts for polymer electrolyte membrane fuel cells (PEM fuel cells) is essential for the widespread use of this technology. The high cost and limited availability of Pt-group metals (PGMs) used as catalyst materials are the main barriers to the widespread commercialization and development of PEM fuel cells. [1] Therefore, the use of high surface area and effective catalysts without Pt have gained great importance in PEM fuel cells. This study introduces high surface area electrocatalysts that are free of platinum group metals (non-PGM) consisting of iron-nitrogen-carbon (Fe-N-C). Here, the uniform distribution of Fe was achieved using graphene oxide (GO) nanoparticles to enhance the catalyst's performance for oxygen reduction reaction (ORR). [2] Furthermore, the addition of a small amount of cerium oxide (CeO2) nanoparticles to the catalyst layer helps to prevent the degradation of the catalyst and ionomer by preventing H2O2 formation as well as increasing the ORR activity due to high oxygen storage capacity. [3] Initially, GO is synthesized by improved Hummer’s method. The GO nanoparticles are obtained through a process involving ball-milling and acid treatment. These nanoparticles are then thermally reduced and nitrogen-doped to form nitrogen-doped reduced graphene oxide nanoparticles. Fe-N-C complexes are synthesized by reacting these nanoparticles with FeCl2 precursor, which are then hydrothermally treated to introduce CeO2 additives. The resulting catalysts are analyzed using various techniques (FT-IR, XPS, SEM, TEM, EDX) and display excellent electrochemical performance. The ORR activity of the Fe-N-C catalysts was investigated and compared with the electrocatalysts prepared with larger graphene oxide particles. A similar comparison is also made with and without CeO2 additives. The authors gratefully acknowledge the financial support of The Scientific and Technological Research Council of Turkey (TÜBİTAK) (Grant Number: 122M429) References [1] He, C., Desai, S., Brown, G., & Bolleplli, S. (2005). PEM fuel cell catalysts: Cost, performance, and durability. The electrochemical society Interface, 14(3), 41.[2] Weiss, J., Zhang, H., & Zelenay, P. (2020). Recent progress in the durability of Fe-NC oxygen reduction electrocatalysts for polymer electrolyte fuel cells. Journal of Electroanalytical Chemistry, 875, 114696.[3] Taşdemir, A., Iskandarani, B., Yürüm, A., Gürsel, S. A., & Kaplan, B. Y. (2021). CeO2 nanorod decorated NrGO additives for boosting PEMFC performance. International Journal of Hydrogen Energy, 46(63), 32250-32260.

Preparation and properties of nitrogen-doped reduced graphene oxide loaded palladium/1,4-bis(phenylethynyl)benzene irreversible hydrogen getters

Preparation and properties of nitrogen-doped reduced graphene oxide loaded palladium/1,4-bis(phenylethynyl)benzene irreversible hydrogen getters

Hierarchical composites based on near-spherical ZnO attached on nitrogen-doped reduced graphene oxide for enhanced nitrite electrochemical sensing property

A hierarchical near-spherical ZnO (ns-ZnO)/Nitrogen-doped reduced graphene oxide (N-rGO) nanocomposite was synthesized via a facile hydro/solvo-thermal route. Then, a non-enzymatic nitrite electrochemical sensor (ns-ZnO/N-rGO/GCE) was obtained by modifying glassy carbon electrode (GCE) with the prepared nanocomposite. More adsorption sites and electro-catalytic active sites were provided at the electrode interface thanks to the formation of hierarchical structure, making the fabricated GCE possess a remarkable amperometric sensing property for nitrite. The limit of detection (LOD) was as low as 0.08 μM, and the detection range was as broad as 0.037 μM–5.9 mM. Furthermore, this sensor showed satisfactory recovery for nitrite in genuine samples including ham sausage, pickle and tap water, suggesting the potential practical application performance of ns-ZnO/N-rGO/GCE in the fields of food analysis and environmental monitoring.

Investigating the impact of nitrogen-doping on the characteristics and performance of reduced graphene oxide for lithium-ion batteries anode through experimental and theoretical study

Recently, graphene-based materials have gained widespread attention due to their remarkable electronic characteristics, which make them ideal for use in a broad range of energy storage applications such as lithium-ion battery (LIB). Despite the potential benefits of graphene-based materials, the process of creating them in a cost-efficient manner remains difficult. Herein, we developed nitrogen-doped reduced graphene oxide (NRGO) through a one-step thermal reduction of graphene oxide (GO) and urea. We evaluated the structure and morphology of NRGO by using scanning electron microscopy (SEM), ultraviolet-visible light (UV–vis) spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy, which revealed a wrinkled, layered structure with 8.4 % nitrogen content. Moreover, we also compared the performance of RGO and NRGO as an anode for LIB through various electrochemical characterizations, i.e., cyclic voltammetry (CV), galvanostatic charge discharge (CD), and electrochemical impedance spectroscopy (EIS). The result indicates that NRGO provides 2.6 faster lithium diffusion compared to RGO. To gain insights into lithium migration pathways, density functional theory based nudged elastic band (DFT-NEB) simulations were performed. The results revealed the energy barrier of lithium migration in graphitic-NRGO is estimated to be 0.15 eV, and for its reverse reaction, a barrier of 0.22 eV is required. In conclusion, the NRGO synthesized through this relatively simple process displays a promising prospect for anode component in LIB and the reaction pathway simulation provides an important insight into the understanding of lithium migration on the NRGO surface and its optimization for LIB applications.

Synthesis, characterization and insights into the supercapacitive and electrocatalytic (OER) bi-functional properties of nitrogen-doped reduced graphene oxide using dicyandiamide precursor

A facile methodology to synthesize the nitrogen-doped reduced graphene oxide (NG) via a solvothermal process exhibiting a substantial content of either pyrrolic-N or pyridinic N, is demonstrated. In the synthesis of NG, different amounts of dicyandiamide (DCDA) with a constant (1 g) amount of graphene oxide have been taken in DMF (solvent). This approach produced the nanosheets of N-doped graphene (NG-2) which possess optimum defect density and 10.58 % total nitrogen. Nitrogen within this NG material predominantly manifests in four distinct bonding configurations, with the most prevalent being pyrrolic-N. The solvothermally synthesized N-doped reduced graphene oxide exhibited good charge storage characteristics. Three electrode testing of NG-2 shows high specific capacitance (865.82 F/g at a particular current density of 0.5 A/g) and a high energy density (76.96 Wh/kg) in acidic conditions. This sample showed poor electrocatalytic activity for oxygen evolution reaction (OER). However, the material prepared with very high amount of DCDA (NG-4) showed a total N-content of 29 % with high contribution of pyridinic N, demonstrated good electrocatalytic activity for OER following the four-electron path. The Tafel slope of NG-4 sample is around 140 mV/dec which implies the facile conversion of OH− into O2, at relatively low overpotential within an alkaline system. Consequently, the synthesized dual-functional N-doped reduced graphene oxide material holds characteristics for the advancement of carbon-based energy storage materials, and simultaneously be utilized as catalyst for OER.

Widely improved supercapacitance properties of zirconium‑cobalt ferrite nanoparticles by N-doped graphene oxide as an electrode in supercapacitor

Recently, supercapacitors have garnered considerable attention as promising energy storage devices owing to their unique characteristics. Ferrites are commonly recognized as an innovative category of porous materials that present prominent features, including substantial pore volume, high chemical stability, and large specific surface area, contingent upon the precise selection of components. In this research, we fabricated the zirconium ferrite (ZrFe2O4), cobalt ferrite (CoFe2O4), zirconium cobalt ferrite (ZrCoFe2O4), and nitrogen-doped reduced graphene oxide (NRGO) combination with ZrCoFe2O4 (ZrCoFe2O4/NRGO). ZrCoFe2O4/NRGO nanocomposite is constructed by a co-precipitation route as an electrode material for the application of supercapacitors devices. The formation of samples was specified by several techniques like transmission electron microscopy (TEM), X-ray diffraction (XRD), fourier transformation infrared (FTIR), energy dispersive X-ray (EDX), and field emission scanning electron microscopy (FESEM) spectra. The results of structural characterization show that the pore diameter of NRGO is 80.259 nm, CoFe2O4 is 24.301 nm, ZrFe2O4 is 3.1651 nm, ZrCoFe2O4 is 62.617 nm, and ZrCoFe2O4/NRGO is 21.112 nm. The charge storage mechanism and electrochemical activity of as-prepared materials were appraised using the galvanostatic charge/discharge (GCD), cyclic voltammogram (CV) methods, and electrochemical impedance spectroscopy (EIS) test. The ZrCoFe2O4/NRGO electrode demonstrated superb electrochemical activity with a specific capacitance (SC) of 307 F g−1 at a current density of 1 A g−1. According to the stability examination, it was found that the maintenance of the initial capacity stood at approximately 97 % after 5000 cycles, indicating notably good electrochemical stability whereas shown lowest resistance in electrochemical impedance spectroscopy. A constructed asymmetric supercapacitor device (ASD) that utilized hybrid ZrCoFe2O4/NRGO//NRGO electrodes indicated a SC of 137 F g−1 at 1 A g−1, energy density of 42.7 Wh kg−1, and power density of 618.5 W kg−1. These findings indicate that the ZrCoFe2O4/NRGO//NRGO composite material has the capability to be employed as unique electrode material in supercapacitor applications to produce high-efficiency and reliable energy storage devices.

Nitrogen-doped reduced graphene oxide/black phosphorus quantum dot composites for electrocatalytic treatment of choroidal melanoma

Choroidal melanoma (CM) is a melanocyte-derived intraocular malignancy that poses a great threat to patients’ vision and life. Electrochemical therapy, which relies on the generation of reactive oxygen species via an oxygen reduction reaction (ORR) to kill target cells, has emerged as a promising approach for the local treatment of malignant tumors. In this study, nitrogen-doped reduced graphene oxide (N-rGO) was electrostatically bound with black phosphorus (BP) quantum dots to form a composite system (N-rGO-BP) for tumor therapy. Owing to the synergistic effect of the two components, the optimal catalyst (N-rGO-BP-12) exhibits improved electrochemical properties and stability, achieving a more positive half-wave potential of 0.66 V and a larger steady-state current density of 2.76 mA cm−2 compared with the N-rGO precursor. In electrochemical therapy, N-rGO-BP-12 undergoes ORR via a two-electron pathway in the acidic microenvironment of the tumor, producing large amounts of hydrogen peroxide and hydroxyl radical to kill tumor cells; only 25 % of the human CM cells survive after 3 h of the treatment. This study provides a new approach for the synthesis and application of electrochemical catalysts for clinical tumor therapy.

Mechanistic insights into the roles of precursor content, synthesis time, and dispersive solvent in maximizing supercapacitance of N-rGO sheets

Graphene oxide (GO) sheets were prepared using the improved Hummers’ method, followed by simultaneous reduction and nitrogen doping using an easy solvothermal route to obtain Nitrogen-doped reduced graphene oxide (N-rGO) sheets. The amount of N-doping was controlled using the different amounts of GO and Urea, keeping the ratio of the two (1:3) fixed. Here, we examined several variations in synthesis parameters, viz. change in precursor content, variation in synthesis time, and volume of dispersive solvent. The N-rGO sample prepared with 250 mg GO and 750 mg urea at 24-hour synthesis time in 80 ml dispersive solvent exhibits a superlative specific capacitance of 1244 F/g at 0.5 A/g using 3-electrode measurements in an acidic medium. The high value can be understood via the synergistic roles of optimum defects, degree of reduction, and types of N-environments. The symmetric 2-electrode device prepared by depositing the synthesized material onto carbon cloth exhibits supercapacitance of 635 F/g at 1 A/g current density and high cyclic constancy with capacitive retention of ∼ 96% after 10000 charge-discharge cycles. Our work provides critical mechanistic insights on the complex intermingling of an optimum N-content, the relative amount of the different N-environments, degree of reduction, and disorder to generate a high specific capacitance, remarkably better than previously reported works on similar materials. Notably, a relatively high graphitic-N, with moderate surface N-content (4.64%) and a moderate degree of reduction, leads to this higher specific capacitance.

Pt-free graphene oxide-hydrogen membrane fuel cells (GOHMFCs)

High-performance conventional proton exchange membrane fuel cells (PEMFCs) typically rely on expensive Pt/C as the catalyst for the hydrogen oxidation reaction (HOR) at the anode and the oxygen reduction reaction (ORR) at the cathode, which suffers from CO poisoning. As a result, there is a surging interest in developing precious metal-free electrocatalysts in fuel cells and metal-air batteries. A promising candidate is graphene, a one-atom-thick monolayer with a 2-dimensional (2-D) hexagonal honeycomb lattice of carbon, which offers an ideal replacement opportunity as an electrocatalyst for the ORR due to its high catalytic activity and tolerance against poisoning. In this study, nitrogen-doped reduced graphene oxide (N-rGO), a low-cost and precious metal-free electrocatalyst for ORR, are synthesized using a hydrothermal method using a low-cost industrial material ammonium formate (NH4HCO2) as both the reductant agent and nitrogen source. Here, we have confirmed the successful formation of N-rGO and reduced graphene oxide (rGO) through a series of analyses on the microstructure, molecular bonding, nanometric composition, and surface chemistry of the materials and their ORR activity. By integrating a membrane electrode assembly (MEA) with MPTS-modified graphene oxide (GO) composite electrolyte (MGC-50), which contains a 50 wt% ratio of (3-mercaptopropyl)trimethoxysilane (MPTS) and GO, we have developed a safe and scalable method for Pt/C-free electrocatalyst application in graphene oxide-hydrogen membrane fuel cells (GOHMFCs). The best performing catalyst (N-rGO-AA@180) exhibited the maximum power density (MPD) of 17.57 mW/cm2 with a load current density (LCD) of 87.50 mA/cm2, significantly better than those of rGO@300, which has an MPD of 5.70 mW/cm2 with an LCD of 23.90 mA/cm2, both measured at 40 °C.

Bismuth oxide and nitrogen-doped reduced graphene oxide co-modified glassy carbon electrode to perform sensitive electrochemical sensing and determination of chrysin in pharmaceutical capsules

A bismuth oxide- nitrogen doped reduced graphene oxide/glassy carbon electrode (Bi2O3-NRGO/GCE) was prepared for the detection of the flavonoid drug chrysin in pharmaceutical capsules, for the first time. Bi2O3 nanosheets synthesized by a hydrothermal method, were ultrasonically mixed with NRGO, and a simple and efficient Bi2O3-NRGO/GCE composite was prepared. The composites were characterized by various methods. Cyclic voltammetry and electrochemical impedance techniques were used to study the electrochemical sensing performance of the composites-modified electrode surface. The electrochemical performance and optimal detection conditions of chrysin on Bi2O3-NRGO/GCE were investigated by differential pulse voltammetry (DPV). The oxidation peak current of chrysin has a linear relationship with its concentration, in the range of 0.01–10 μM, with a detection limit of 2.0 nM. Bi2O3-NRGO/GCE also has good selectivity for chrysin, which is not interfered with by common inorganic salts and common organic substances, or by structurally similar substances. The composite electrode also has good repeatability, reproducibility and stability. It shows that utilizing Bi2O3 and NRGO binary complexes modified electrodes for ultrasensitive chrysin sensing is a simple and convenient detection method, with promising applicability in the development of pharmaceutical component sensing technology.

N-Doped Graphene Nanofibers with Porous Channel Comprising Fe x S y Nanocrystals and Intertwined N-Doped CNTs as Efficient Interlayers for Li-S Batteries

Hierarchically porous and conductive nanofibers (NFs) comprising nitrogen-doped reduced graphene oxide (N-rGO) and iron sulfide (Fe x S y ) nanocrystals along with highly intertwined nitrogen-doped carbon nanotubes (N-CNTs) abbreviated as “P-rGO@Fe x S y /N-CNT NFs” were synthesized via electrospinning technique as multifunctional interlayers via coating on the commercial separator for stable lithium-sulfur (Li-S) batteries. The porous N-rGO framework acts as a backbone to enhance the structural integrity of the nanostructure. The N-CNTs and N-rGO guarantee various conductive channels for quick electron transfer thus allowing fast redox reactions. The thermal breakdown of polystyrene (PS) resulted in the formation of continuous longitudinal channels. Correspondingly, the Li-S cell incorporating the P-rGO@Fe x S y /N-CNT NF-modified separator and S electrode (2.41 mg cm-2) exhibited boosted electrochemical properties such as justifiable rate capability and steady cycling performance (after 800 charge-discharge, cell exhibits a capacity of 464 mA h g-1 with 44% retention at 0.1 C). The novel synthesis strategy discussed herein will provide significant intuitions to the advancement of innovative nanostructures for different rechargeable purposes.