Graphitic Carbon Nanoparticles Research Articles

Efficient adsorptive removal of 2,4-dichlorophenoxyacetic acid (2,4-D) using biomass derived magnetic activated carbon nanocomposite in synthetic and simulated agricultural runoff water

This study focused on evaluating the efficacy of a magnetic activated carbon material (CPAC@Fe3O4) derived from pods of copper pod tree in adsorbing the toxic herbicide, 2,4- (2,4-D) from aqueous solutions. The synthesized CPAC@Fe3O4 adsorbent, underwent various characterization techniques. FESEM images indicated a rough surface, incorporating iron oxide nanoparticles, while EDS analysis confirmed the presence of elements like Fe, O, and C. Notably, the CPAC@Fe3O4 exhibited high surface area (749.10 m2/g) and pore volume (0.5351 cm³/g), confirming its mesoporous nature. XRD investigations identified distinct signals associated with graphitic carbon and magnetite nanoparticles, while VSM analysis verified its magnetic properties with a high magnetic saturation value (2.72 emu/g). The adsorption process was exothermic, with a decrease in adsorption capacity at higher temperatures. Freundlich isotherm provided the best fit for the adsorption, and the pseudo-second-order equation effectively described the kinetics. Remarkably, the maximum adsorption capacity ranged from 246.43 to 261.03 mg/g, surpassing previously reported values. The ΔH° value (−8.67 kJ/mol) suggested a physisorption mechanism, and the negative ΔG° values established the spontaneous nature. Furthermore, the synthesized adsorbent demonstrated exceptional reusability, allowing for up to five cycles of adsorption-desorption operations. When applied to simulated agricultural runoff, CPAC@Fe3O4 showcased a significant adsorption capacity of 160.71 mg/g for 50 mg/L 2,4-D, using a 0.2 g/L dosage at pH 2. This study showcased the transformation of copper pod biomass into a valuable magnetic nanoadsorbent capable of efficiently eliminating the noxious 2,4-D pollutant from aqueous environments.

Surface modification by CO2 plasma boosting core shells structural Fe/Fe3C/FeN @ graphite carbon nanoparticles toward high performance microwave absorber

The surface modification of three-dimensional (3D) materials is an efficient method for adjusting their interfacial defect concentration, electronic conductivity and content of functional groups with extensive applications in catalysis, electrode materials and bioengineering. In this work, a multiphase iron nanocrystals consisting of Fe3C, Fe and FeN nanoparticles encapsulated in hierarchical structure of graphite carbon (denoted as Fe/Fe3C/FeN@GC) is synthesized for the first time by a novel high temperature plasma method. Meanwhile, more defects and functional groups are introduced by surface modification of graphite carbon layer of Fe/Fe3C/FeN@GC with controllable CO2 (low temperature) plasma. Benefiting from the advantages of multiple heterogenous interface and the abundant interfacial polarization relaxation that represent strong electromagnetic (EM) wave dissipation as well as an applicable impedance matching, the optimized Fe/Fe3C/FeN@GC demonstrate superior microwave absorption (MA) properties. The minimum reflection loss (RL) achieves −54.4 dB (more than 99.9% MA) at 17.6 GHz with a thin thickness of 1.8 mm, and the maximum effective absorption bandwidth (EAB, RL < −10 dB) is up to 6.2 GHz (11.8–18.0 GHz) at 2.0 mm. The above results reveal that the optimized Fe/Fe3C/FeN@GC composites with strong absorption, broad EAB, light mass (only filling content of 30 wt%) and ultrathin thickness are prospective candidate for high performance EM wave absorbers.

Temperature-controlled dual-selectivity nitric oxide/acetone sensor constructed from mesoporous SnO2 tubes doped by biomass-derived graphitic carbon

How to achieve good dual-functional selectivity of metal oxide-based sensors to harmful gases remains challenge due to few relevant reports. To this purpose, we selected waste willow catkins as structure-oriented template and carbon source to controllably prepare biomorphic GC/SnO2-500 sensing material by air calcination of 500 °C. Its tubular morphology is cross-linked by 3.51 wt% biomass-derived graphitic carbon (GC) and small-size nanoparticles. It has relatively large specific surface area, uniform mesopore distribution and rich oxygen vacancies. The synergistic effect of above positive factors promotes the rapid gas transport to sensing layer, and also increases the reactive sites and its resistance modulation ability, thus achieving good dual-functional selectivity. At 92 °C, GC/SnO2-500 sensor displays large response value of 802 to 10 ppm NO, and exhibits a good response towards 100 ppm acetone at 217 °C (S = 22). Both of the indexes are better than those of most corresponding gas sensors reported presently. Meanwhile, the sensor has short response time, satisfactory long-term stability and humidity tolerance. Moreover, portable temperature-dependent dual-functional gas-sensing mechanism is also discussed.

Multiple carbon interface engineering to boost oxygen evolution of NiFe nanocomposite electrocatalyst

Interface engineering has been widely investigated to regulate the structure and performance of electrodes and photoelectrodes, but the investigation of multiple carbon interface modifications on the electrocatalytic oxygen evolution reaction (OER) is still shortage. Herein, we report remarkable promotion of OER performance on the NiFe-based nanocomposite electrocatalyst via the synergy of multiple carbon-based interface engineering. Specifically, carbon nanotubes were in situ grown on carbon fiber paper to improve the interface between CFP and NiFeOxHy, and graphite carbon nanoparticles were in situ loaded and partly doped into the NiFeOxHy to modify the intergranular interface charge transfer and electronic structure of NiFeOxHy. Consequently, the as-obtained NiFeOxHy-C/CNTs/CFP catalyst exhibited significantly enhanced electrocatalytic OER activity with an overpotential of 202 mV at 10 mA cm−2 in 1 mol L−1 KOH. Our work not only extends application of carbon materials but also provides an alternative strategy to develop highly efficient electrocatalysts.

Low-temperature synthesis of graphite flakes and carbon-based nanomaterials from banana peels using hydrothermal process for photoelectrochemical water-splitting

Herein, we report the synthesis of carbon nanostructures from banana peels at low hydrothermal temperatures. A one-step hydrothermal method was used, and the desired product was obtained at 220 °C using two dispersant solvents (distilled water (S1) and ethanol (S2)). The formation of carbon nanomaterials and graphite flakes has been confirmed through various characterization techniques. The Scanning Electron Microscopy (SEM) analysis shows a graphite flake-like morphology using water as a solvent and a mix-up of graphite flakes and carbon nanoparticles presence using ethanol as a solvent. Two primary elements i-e., carbon (C) and oxygen (O) were observed in the Energy Dispersive X-ray (EDX) analysis. The X-ray Diffraction (XRD) analysis shows the graphitic diffraction peak that confirms the formation of graphite flakes and carbon nanomaterials with good crystallinity . Fourier Transform Infrared (FTIR) analysis reveals the signature of O–H, C–H, C–O, C–O 2 , bonds along with C O and C C bonds. UV–Visible (UV–Vis) spectroscopy shows absorption at 230 nm for (S2) and 270 nm for (S1) which correspond to the π-π* and n-π* transitions of C C and C O, respectively. The photoelectrochemical (PEC) analysis shows that the sample (S2) has a higher photocurrent density and low charge-transfer-resistance than the sample (S1) because of its finer size. The study thus provides a simple pathway for the preparation of carbon-based nanomaterials on a large scale. • Graphite flakes and carbon-based nanostructures were prepared through a one-step hydrothermal route from banana peels. • Two dispersant solvents i-e, ethanol and water were used as a media in the reaction procedure. • SEM reveals graphite flakes and nanoparticle shape morphology while XRD shows the graphitic peak (002) with good crystallinity. • FTIR shows the signature of C–H, C–O, C–O 2 bonds along with C O and C C bonds. • Photoelectrochemical analysis shows higher photocurrent density and flat-band potential, and low charge-transfer-resistance for the sample prepared in ethanol.

Impact of N2 admixture on the synthesis of graphitic carbon nanoparticles using atmospheric-pressure microwave plasma

Atmospheric-pressure microwave plasma was utilized for catalyst-free gas-phase synthesis of graphitic carbon nanoparticles by adding CH4 to a mixture of N2 and He. The impact of N2 on the formation of the graphitic carbon nanoparticles was analyzed by increasing the N2 flow rate from 0 to 20 slpm and decreasing the He flow rate from 40 to 20 slpm simultaneously. The addition of N2 altered the morphology of the carbon nanoparticles to obtain flatter and larger shapes. Furthermore, carbon nanoparticles synthesized with N2 possessed more graphitic structures with higher C/O ratios and larger crystallite sizes than those synthesized without N2. The analysis of gas compositions at thermodynamic equilibrium states demonstrated that CN and HCN were the dominant precursor species when N2 was added. The presence of N atoms or N-containing species seem to have a synergistic effect combined with H atoms on the formation of the graphitic carbon nanoparticles.

Hierarchical Graphitic Carbon-Encapsulating Cobalt Nanoparticles for Catalytic Hydrogenation of 2,4-Dinitrophenol

Cobalt hierarchical graphitic carbon nanoparticles (Co@HGC) (1), (2), and (3) were prepared by simple pyrolysis of a cobalt phenanthroline complex in the presence of anthracene at different temperatures and heating times, under a nitrogen atmosphere. The samples were used for the catalytic hydrogenation of 2,4-dinitrophenol. Samples (1) and (3) were prepared by heating at 600 °C and 800 °C respectively, while (2) was prepared by heating at 600 °C with an additional intermediate stage at 300 °C. This work revealed that graphitization was catalyzed by cobalt nanoparticles and occurred readily at temperatures of 600 °C and above. The nanocatalysts were characterized by Scanning Electron Microscopy SEM, energy dispersive X-ray analysis EDX, Raman, Xrd, and XPS. The analysis revealed the presence of cobalt and cobalt oxide species as well as graphitized carbon, while TEM analysis indicated that the nanocatalyst contains mainly cobalt nanoparticles of 3–20 nm in size embedded in a lighter graphitic web. Some bamboo-like multiwall carbon nanotubes and graphitic onion-like nanostructures were observed in (3). The structures and chemical properties of the three catalysts were correlated with their catalytic activities. The apparent rate constants kapp (min−1) of the 2,4-dinitrophenol reductions were 0.34 for (2), 0.17 for (3), 0.04 for (1), 0.005 (no catalyst). Among the three studied catalysts, the highest rate constant was obtained for (2), while the highest conversion yield was achieved by (3). Our data show that an increase in agglomeration of the cobalt species reduces the catalytic activity, while an increase in pyrolysis temperature improves the conversion yield. The nanocatalyst enhances hydrogen generation in the presence of sodium borohydride and reduces 2,4-dinitrophenol to p-diamino phenol. The best nanocatalyst (3) was prepared at 800 °C. It consisted of uniformly distributed cobalt nanoparticles sheltered by hierarchical graphitic carbon. The nanocatalyst is easily separated and recycled from the reaction system and proved to be degradation resistant, to have robust stability, and high activity towards the reduction reaction of nitrophenols.

Effects of In Situ Graphitic Nanocarbon Coatings on Cycling Performance of Silicon-Flake-Based Anode of Lithium Ion Battery

We coated graphitic nanocarbons by thermal chemical vapor deposition (CVD) on silicon flakes recycled from the waste of silicon wafer manufacturing processes as an active material for the anode of lithium ion battery (LIB). Ferrocene contains both iron catalyst and carbon, while camphor serves as an additional carbon source. Water vapor promotes catalytic growth of nanocarbons, including carbon nanotubes (CNTs), carbon fibers (CFs), and carbon films made of graphitic carbon nanoparticles, at temperatures ranging from 650 to 850 °C. The container of silicon flakes rotates for uniform coatings on silicon flakes of about 100 nm thick and 800–1000 nm in lateral dimensions. Due to short CVD time, besides CNTs and CFs, surfaces of silicon flakes deposit with high-density graphitic nanoparticles, especially at a low temperature of 650 °C. Nanocarbon coatings were characterized by SEM, EDX, ESCA, and Raman spectroscopy. Half-cells were characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and retention of capacity in discharge/charge cycling. Silicon-flake-based anode with nanocarbon coatings at both 650 and 850 °C exhibited capacity retention of 2000 mAh/g after 100 cycles at 0.1 C, without needing any conductivity enhancement material such as Super P.

Writing ink-promoted synthesis of electrodes with high energy storage performance: A review

As the low-cost commercial product, writing inks (pen ink and Chinese ink) have attracted great attention to fabricate electrochemical electrodes for supercapacitors (SCs) and batteries. Due to the conductive nature deriving from graphitic carbon nanoparticles in ink and strong adhesion, ink can be easily coated onto support to enhance the conductivity, form a porous layer facilitating electrolyte ion diffusion, increase the specific surface area and function as binder and dispersant for other active materials. In this review, the beneficial features of pen ink and Chinese ink are summarized and how these features favor the electrochemical performance is discussed in details. And then, ways to coat ink onto support are described, giving a clear understanding of recent process in this area. Finally, the current challenges and outlook of ink-based electrode are discussed, aiming to offer some basic knowledge and promote wide application and future study of pen ink and Chinese ink in electrochemistry.

Hierarchical carbonaceous composites with dispersed Co species prepared using the inherent nanostructural platform of biomass for enhanced microwave absorption

Abstract Task-specific carbonaceous composites which can inherently inherit the nanostructures of biomass precursors have aroused great attention due to the characteristics of unique macro-/microporous structures, vastly available and renewability. Herein, aiming for efficient microwave absorption, hierarchical porous C/Co composites were prepared by simple dipping and carbonization process using agarics as hierarchical framework platform for magnetic Co species. The role of Co nanoparticles, Co loading amounts and carbonization temperature were systematically investigated by establishing the relationship between structural characteristics and microwave absorption performance. The prepared samples displayed enhanced microwave absorption performance than the pure carbon derived from agarics; it could mainly attribute to the synergistic effect between graphite carbon and Co nanoparticles. When the filling rate was 30%, the HPC/Co-800 showed the best EM wave absorption performance. The minimum RL was −52.62 dB at 8.56 GHz in 2.8 mm. The widest absorption bandwidth reached 5.44 GHz when the RL was −49.63 dB at only 1.9 mm. This work may pave a new avenue to develop sustainable high effective absorber by recyclable biomass materials.

Synthesis of Ag–Carbon–TiO2 composite tubes and their antibacterial and organic degradation properties

Ag–Carbon–TiO2 composite tubes were prepared by using polystyrene/AgNO3 composite fibers as a sacrifice template and a co-pyrolysis process. The Ag–Carbon–TiO2 tubes were characterized by SEM, TEM, X-ray diffraction, Raman spectrum, XPS, and UV–vis spectrum. The results showed that the Ag–Carbon–TiO2 tubes possessed uniform tubular structure with amorphous carbon, graphitic carbon, and Ag nanoparticles (AgNPs) distributing uniformly in TiO2. The Ag–Carbon–TiO2 tubes were confirmed high UV–vis light utilization and photocatalytic degradation efficiency to Rhodamine B due to the carbon doping, the surface plasmon resonance of AgNPs and the tubular structure, and the degradation of Rhodamine B reached 90% in 6 h. Meanwhile, they showed an excellent antibacterial effect on staphylococcus aureus, and the fatality rate of Ag–Carbon–TiO2 tubes to staphylococcus aureus reached 99.9% in 24 h when its concentration was higher than 4 mg/ml. The co-pyrolysis process could repress the AgNPs to grow to be large particles, which could be a key for the excellent antibacterial property. The research showed a promising strategy for preparing Ag–Carbon–TiO2 composite tubes by co-pyrolysis of PS composite electrospinning fibers, indicating their potential application in wastewater treatment and antibacterial materials.

α-Fe2 O3 Nanoparticles Decorated C@MoS2 Nanosheet Arrays with Expanded Spacing of (002) Plane for Ultrafast and High Li/Na-Ion Storage.

MoS2 nanosheets as a promising 2D nanomaterial have extensive applications in energy storage and conversion, but their electrochemical performance is still unsatisfactory as an anode for efficient Li+ /Na+ storage. In this work, the design and synthesis of vertically grown MoS2 nanosheet arrays, decorated with graphite carbon and Fe2 O3 nanoparticles, on flexible carbon fiber cloth (denoted as Fe2 O3 @C@MoS2 /CFC) is reported. When evaluated as an anode for lithium-ion batteries, the Fe2 O3 @C@MoS2 /CFC electrode manifests an outstanding electrochemical performance with a high discharge capacity of 1541.2 mAh g-1 at 0.1 A g-1 and a good capacity retention of 80.1% at 1.0 A g-1 after 500 cycles. As for sodium-ion batteries, it retains a high reversible capacity of 889.4 mAh g-1 at 0.5 A g-1 over 200 cycles. The superior electrochemical performance mainly results from the unique 3D ordered Fe2 O3 @C@MoS2 array-type nanostructures and the synergistic effect between the C@MoS2 nanosheet arrays and Fe2 O3 nanoparticles. The Fe2 O3 nanoparticles act as spacers to steady the structure, and the graphite carbon could be incorporated into MoS2 nanosheets to improve the conductivity of the whole electrode and strengthen the integration of MoS2 nanosheets and CFC by the adhesive role, together ensuring high conductivity and mechanical stability.

Effect of Morphological Changes due to Increasing Carbon Nanoparticles Content on the Quasi-Static Mechanical Response of Epoxy Resin.

Mechanical failure in epoxy polymer and composites leads them to commonly be referred to as inherently brittle due to the presence of polymerization-induced microcrack and microvoids, which are barriers to high-performance applications, e.g., in aerospace structures. Numerous studies have been carried out on epoxy’s strengthening and toughening via nanomaterial reinforcement, e.g., using rubber nanoparticles in the epoxy matrix of new composite aircraft. However, extremely cautious process and functionalization steps must be taken in order to achieve high-quality dispersion and bonding, the development of which is not keeping pace with large structures applications. In this article, we report our studies on the mechanical performance of an epoxy polymer reinforced with graphite carbon nanoparticles (CNPs), and the possible effects arising from a straightforward, rapid stir-mixing technique. The CNPs were embedded in a low viscosity epoxy resin, with the CNP weight percentage (wt %) being varied between 1% and 5%. Simplified stirring embedment was selected in the interests of industrial process facilitation, and functionalization was avoided to reduce the number of parameters involved in the study. Embedment conditions and timing were held constant for all wt %. The CNP filled epoxy resin was then injected into an aluminum mold and cured under vacuum conditions at 80 °C for 12 h. A series of test specimens were then extracted from the mold, and tested under uniaxial quasi-static tension, compression, and nanoindentation. Elementary mechanical properties including failure strain, hardness, strength, and modulus were measured. The mechanical performance was improved by the incorporation of 1 and 2 wt % of CNP but was degraded by 5 wt % CNP, mainly attributed to the morphological change, including re-agglomeration, with the increasing CNP wt %. This change strongly correlated with the mechanical response in the presence of CNP, and was the major governing mechanism leading to both mechanical improvement and degradation.

Langmuir probe characterisation of an Ar–H2 non-thermal plasma loaded with carbon nanoparticles

In this contribution, we describe the development of a test-bed for the characterisation of non-thermal dusty plasmas via Langmuir probe. This technique, while allowing the precise determination of plasma parameters and electron energy distribution function (EEDF), is notoriously difficult to apply in dust-forming chemistries. We overcome this limitation by utilising a two-plasmas system in which the particle precursor, in this case acetylene, is fully consumed and converted into nanoparticles in a first plasma reactor, followed by the injection of the dust into a second plasma reactor where the Langmuir probe measurement is performed. This approach allows studying the influence of the variation of process parameters on the dusty plasma properties, all while leaving the nucleation and growth phase of the particles unaffected and fully decoupled from the discharge in which the measurement takes place. We have applied this approach to the case of graphitic carbon nanoparticles dispersed in an argon–hydrogen mixture. We have monitored the quality of the Langmuir probe measurement, and found that it is minimally affected by the presence of the graphitic particles even after several EEDF measurements. Our measurements confirm the unipolar charging of nanoparticles in non-thermal plasmas, consistent with previous observations and theoretical predictions. We also observe an unexpected trend with plasma input power: the charge carried by the particles does not monotonically increase with increased power, instead starts decreasing at sufficiently high input power levels.

Multiband Fluorescent Graphitic Carbon Nanoparticles from Queen of Oils

Here, we report a facile and rapid approach for the synthesis of multiband fluorescent graphitic carbon nanoparticles (CNPs) from queen of oils exhibiting multifarious applications. The as-prepared...

High-energy aqueous Li-ion hybrid capacitor based on metal-organic-framework-mimicking insertion-type copper hexacyanoferrate and capacitive-type graphitic carbon electrodes

A high-performance aqueous Li-ion hybrid capacitor (LHC) using sonochemically prepared copper hexacyanoferrate (Cu-HCF) and sodium alginate-derived graphitic carbon (GC) nanoparticles are capable of serving as positive and negative electrodes, respectively, is described in this report. The electrode materials were prepared in a cost-effective manner and characterized using X-ray diffraction (XRD) and Fourier transform-infrared spectroscopy (FT-IR). High-resolution transmission electron microscopy (HR-TEM) and surface area measurements revealed the formation of 30- to 60-nm Cu-HCF and 40- to 60-nm GC particles with specific surface areas of 48 and 802 m2g–1, respectively. Electrochemical studies including cyclic voltammetry (CV), galvanostatic charge-discharge (CD) analysis and electrochemical impedance spectroscopy (EIS) using a three-electrode configuration confirmed the presence of intercalative capacitance in the Cu-HCF electrode and double-layer capacitance in the GC electrode. Furthermore, the constructed Cu-HCF‖GC aqueous LHC system operates over a wide voltage window (2.2 V) and delivers a high capacitance (63.64 F g−1) and high energy density (42.78 Wh kg−1) with a good rate capability. These key features make the LHC system an ideal candidate for next-generation electrochemical energy storage devices.

Carbonization temperature controlled thermal conductivity of graphitic carbon nanoparticles and their polymer composites

Carbon materials as versatile fillers have drawn increasing attention in thermal conductive polymer composites, however, the thermal conductivity (TC) regulation of them remains challenging. Herein, the tunable lattice thermal conductivity is reported for glucose derived graphitic carbon nanoparticles (GCPs) and their polymer composites. Both the in-plane (La) and out-of-plane (Lc) coherence lengths of GCPs increase with carbonization temperature in the range of 700 °C to 1300 °C. The intrinsic TC of GCPs film is directly extracted from the dependence of the Raman G peak frequency on the excitation laser power and the first order temperature coefficient. It is found that the in-plane lattice TC increases exponentially with both of the increasing La and decreasing defect concentration. The GCPs are then used as highly processible fillers to fabricate thermoset composites based on reactive benzoxazine (BA-a). The total TC of the poly(BA-a)/GCPs are found increase monotonically from 0.27 W·m-1·K-1 to 0.34 W·m-1·K-1 with the increasing graphitization levels of GCPs, and a clear signature of thermal percolation threshold at 6 vol% GCPs loadings is also observed.

Unzipping of Single-Walled Carbon Nanotube for the Development of Electrocatalytically Active Hybrid Catalyst of Graphitic Carbon and Pd Nanoparticles.

We demonstrate a new approach for the unzipping of single-walled carbon nanotube (SWCNT) in an aqueous solution using the transition metal complex PdCl42– as a sacrificial chemical scissor and the growth of graphitic-carbon-coated Pd nanoparticles for the electrocatalytic oxidation of formic acid. The chemical unzipping and the growth of Pd nanoparticles involve the spontaneous electron transfer between SWCNT and the metal complex in an aqueous solution at room temperature. The redox potential for SWCNT and PdCl42– favors the spontaneous electron transfer reaction. The metal complex, in situ generated Pd nanoparticle, and oxygen play vital role in the oxidative unzipping of SWCNT. The Pd nanoparticles have an average size of 11 nm and are coated with the graphitic carbon layer of unzipped SWCNT (UzCNT-Pd). The Pd nanoparticle of the UzCNT-Pd hybrid material has a large electrochemically active surface area of 2.14 cm2. The hybrid material exhibits excellent electrocatalytic activity toward the oxidation of formic acid. The area and mass specific activity are significantly higher than those of the traditional carbon-supported Pd nanoparticle. The synergistic effect of graphitic carbon and the metal nanoparticles controls the catalytic activity. The confinement of Pd particles inside the graphitic carbon enhances the overall performance of the catalyst.

Fabrication of Water Jet Resistant and Thermally Stable Superhydrophobic Surfaces by Spray Coating of Candle Soot Dispersion

A facile synthesis method for highly stable carbon nanoparticle (CNP) dispersion in acetone by incomplete combustion of paraffin candle flame is presented. The synthesized CNP dispersion is the mixture of graphitic and amorphous carbon nanoparticles of the size range of 20–50 nm and manifested the mesoporosity with an average pore size of 7 nm and a BET surface area of 366 m2g−1. As an application of this material, the carbon nanoparticle dispersion was spray coated (spray-based coating) on a glass surface to fabricate superhydrophobic (water contact angle > 150° and sliding angle < 10 °) surfaces. The spray coated surfaces were found to exhibit much improved water jet resistance and thermal stability up to 400 °C compared to the surfaces fabricated from direct candle flame soot deposition (candle-based coating). This study proved that water jet resistant and thermally stable superhydrophobic surfaces can be easily fabricated by simple spray coating of CNP dispersion gathered from incomplete combustion of paraffin candle flame and this technique can be used for different applications with the potential for the large scale fabrication.

Resorcinol Formaldehyde Based Electrospun Carbon Fibers As High Capacity Anode Material for Lithium Ion Batteries

Introduction Resorcinol formaldehyde (RF) polymer derived carbon gels have been widely used as active electrode material in energy storage devices such as supercapacitors and lithium ion batteries due to their tunable surface area by varying drying conditions.1 In addition to the easily tunable surface area, morphology can also be modified by changing the synthesis parameters and methods.2,3 However, RF xerogel derived carbon nanofibers were not studied as anode material for Li-ion battery due to its non-electrospinnability. Recently, RF-based electrospun carbon nanofibers were prepared by blending it with stretchable Polymethyl methacrylate (PMMA).4 In this work, we have synthesized RF xerogel and PMMA blend based carbon nanofibers and used them as potential anode material for lithium ion battery. These RF xerogel derived electrospun carbon nanofibers show larger lithium ion intercalation capacity not only as compared to RF xerogel derived other carbon morphologies such as powder, interconnected carbon nanoparticles but also other carbon nanofibers based electrodes.5 , 6 Experimental RF sol was prepared by mixing resorcinol and formaldehyde (4:1 molar ratio) in acetone and HCl. Thus prepared RF sol was blended with templating PMMA polymer (1:2 Vol. ratio). A blend of this solution was used as precursor material for electrospinning. Electrospinning process parameters were tuned to yield long, continuous fibers. Controlled two step pyrolysis of these RF xerogel/PMMA electrospun fibers yielded carbon nanofibers. Results and discussions: RF-PMMA blend polymer fibers were electrospun directly on stainless steel wafer used as a substrate cum current collector. Average diameter of RF-PMMA electrospun RF-PMMA nanofibers as shown in Figure 1a was found to be 2.3 µm. These fibers were then pyrolyzed at 900 ⁰C to obtain carbon fibers with average diameter 1.4 µm. X-ray diffraction and Raman spectroscopy studies were done in order to confirm the glassy nature of as-derived carbon nanofibers. These RF-PMMA derived carbon nanofibers based electrode was then used as working electrode in Li (reference electrode) based half-cell. Galvanostatic charge discharge experiments were carried out at 37.2 mA/g current density. An initial reversible capacity of 620 mAh/g (Figure 1b) was observed for these carbon nanofibers which was significantly higher than reported values in literature for RF based powder, RF based graphitic powder and carbon nanoparticles. Further, cyclic stability and coulombic efficiency were found to be excellent. A detailed characterization of these carbon nanofibers and their electrochemical performance at different current densities will be presented during the conference.