Graphite Powder Research Articles

SORPTION OF Fe(III) IONS ON CARBON NITRIDES SYNTHESIED FROM VARIOUS PRECURSORS

In the present work, graphitic carbon nitride powders synthesized from urea, melamine and dicyandiamide were ultrasonic exfoliated and used to evaluate their adsorption efficiency for iron ions –Fe(III) from aqueous solution. It has been established that the efficiency of sorption is significantly influenced by the pH of the medium, contact time, weight of the sorbent and the initial concentration of Fe(III). High adsorption of the iron ion (97–99%) occurs at pH4. It is shown that the Fe(III) sorption isotherm on the studied carbon nitride samples can be modeled by both Langmuir and Freundlich adsorption isotherms based on correlation coefficients

Investigation into the sheet metal forming process using solid granules medium with graphite powder addition

ABSTRACT The solid granules medium sheet metal forming process uses loose particles instead of a rigid convex mold in the deep drawing process. This study focused on a mixed medium of solid granules with added graphite powder , establishing numerical models for four different proportions of graphite powder-solid granules mixtures. A finite element simulation of deep drawing was conducted using 08AL sheets. A deep drawing test shows that the thickness distribution curve closely aligns with the numerical simulation. By adding graphite powder to the solid granules medium, the lubrication conditions between the granules and the sheet metal can be modified, increasing the thickness in the fracture-prone areas of the cylindrical part. Utilizing this numerical model yields thickness distribution and deformation characteristics that closely resemble those observed in deep drawing tests, thereby contributing significantly to the optimization and advancement of this forming technology.

Preparation of phosphorous ionic liquids and its effect on the properties of ABS

AbstractTo improve the thermal conductivity and mechanical properties of graphene‐acrylonitrile butadiene‐styrene plastic (ABS) composite, sub‐phosphite‐based ionic liquid (IL) was synthesized, and its structure was characterized by FTIR, NMR, and mass spectrometry. IL was as a modifier, and graphite powder (G powder) was modified by the ball milling method to obtain functional graphene thermal conductive filler (G‐IL). The structure and morphology of G‐IL were characterized by FTIR, X‐ray photoelectron spectroscopy (XPS), XRD, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results of the Molau test showed that the presence of IL improved the interfacial interaction of G‐IL and ABS, enhanced the dispersion of G‐IL in the ABS matrix, made G‐IL contact with each other, and it was easier to establish a thermal conduction network and promote phonon transfer. The thermal conductivity of 9 wt% G‐IL/ABS composite was 0.392 W·m−1·k−1, which was 96% and 14% higher than that of pure ABS and G/ABS composite, respectively. The tensile strength and bending modulus of 9 wt% G‐IL/ABS composite were 44.89 and 2124.37 MPa, which were 13% and 11% higher than those of pure ABS, respectively. The impact strength of 9 wt% G‐IL/ABS composite was 34.17 kJ/m2. It was 18% and 7% higher than that of pure ABS and 9 wt% G‐IL/ABS, respectively.Highlights Phosphorus imidazole ionic liquids were prepared. Graphene was modified by ionic liquids through non‐covalent. Enhanced mechanical properties and thermal conductivity of G‐IL/ABS composites.

Development of a sustainable and disposable modified Bi-CdFe2O4 electrode for electrochemical sensing of lead (II) and Acetaminophen drug molecule

The study of research proposes a systematic pattern for optimization and fabrication of a sustainable-cost effective electrochemical sensor made by Bi-CdFe2O4 (BCDF) nanoparticle and graphite powder. The structural examinations of synthesized BCDF materials were analyzed by specific spectral techniques viz.; P-XRD, SEM-EDX, TEM, XPS, FT-IR and DRS techniques. The modified sensor electrode offer a significant electrochemical properties that can improve the material selectivity and sensitivity actions measured by Cyclic Voltammetric (CV) and Electrochemical Impedance Spectral (EIS) plots. We demonstrated a developed highly-purity BCDF-graphite paste electrode for sensing actions on Paracetamol and Lead (Pb2+) ions under 0.1 M KCl. The excellent sensing activity towards Lead ions and Paracetamol confirmed by its redox potential peaks at scan rate of 1–5 V/s with maximum sensitivity of -0.61 V and 0.69 V respectively. The excellent photo-dye-degradation action of BCDF (98.2%) than those of host CDF (81.6%) on Rose Bengal (RB) dye was demonstrated. Its kinetic study reveals that this process follows first order kinetics and rate constants of the host (18.1 × 10−3 min−1) and BCDF (39.2 × 10−3 min−1) were measured. Thus, the synthesized BCDF electrode provides a new perception for developing specific nano-sensor towards detection of toxic metals.

Fabrication and electromagnetic wave absorption modulation of high-performance (TaNbTiV)₂AlC MAX phase

Electromagnetic (EM) wave technology is widely used in both military and civilian applications, increasing interest in EM wave absorption materials for information security and environmental protection. This study examines the synthesis and EM wave absorption properties of M-site compositional complex MAX phase (TaNbTiV)2AlC. Using Ta, Nb, Ti, V, Al, and graphite powders, pure (TaNbTiV)2AlC was synthesized at 1400 °C. SEM and EDS confirmed homogeneous elemental distribution and morphology, while TEM and SAED analyses revealed the atomic structure. EM wave absorption was tested using (TaNbTiV)2AlC/paraffin wax composites with varying (TaNbTiV)2AlC content in the 2–18 GHz range. The main attenuation mechanisms identified were interfacial polarization, dielectric loss, and conductive loss. Optimal absorption was achieved at 30 vol% (TaNbTiV)2AlC, with a reflection loss of −43.83 dB and an effective absorption bandwidth of 3.49 GHz. The study demonstrates that the control of establishing a “near-conductive network” of fillers could be advantageous in achieving optimal electromagnetic wave absorption performance using fillers possessing high electrical conductivity, such as MAX phase materials.

From waste to material strategy: A closed-loop regeneration process of spent LiFePO4 batteries

A closed-loop regeneration route to recover valuable elements from spent LiFePO4 batteries is proposed. After hot-acid leaching, the leaching rates of Li, Fe and P are above 99.8 %, and the graphite powder retain in the residue with grade of 93.33 %. With iron powder cementation, 99.96 % Cu is removed from acid leaching solution to obtain sponge copper. And then 96.67 %Al and 89.30 %F are precipitated in the form of AlPO4(s) and FeF3(s) at pH = 3.75. Li, Fe and P within the purified solution are prepared as LiFePO4 precursors by co-precipitation method, and finally LiFePO4/C materials are synthesized after two-stage calcination. The recycled LiFePO4/C materials demonstrate excellent electrochemical performance with a discharge capacity of 153.1 mAh·g−1 at 0.1C and a capacity retention of 94.0 % after 500 cycles at 1C. The present recycling process provides a strategy for short and efficient regeneration of spent LiFePO4 batteries.

Effect of Mixing Methods and Black Conductive Fillers on Properties of Natural Rubber Composites

Carbon black, graphite, carbon nanofibers, carbon nanotubes, and metal fillers increase composite conductivity in natural rubber, which is electrically insulating. Depending on dispersion, conductive filler lowers insulating material resistivity. These materials are frequently used for electromagnetic/radio frequency interference (EMI/RFI) shielding, conductive flexible seals gaskets, and conductive mats used to prevent electrostatic damage to electronic devices. These elastomers could be used to make flexible solar cells or mechanical-to-electricity devices. Temperature, mixing time, shear rate, and cross-linking during vulcanization affect rubber electrical conductivity of composite. To study shear rate effects, vulcanizate of Natural Rubber-based composites filled with carbon black, millable carbon fiber powder, and synthetic graphite powder was prepared by open mixing (two roll mill) and close mixing (internal mixer). We compared how shear rate affects cure, stress-strain, and volume resistivity of conductive filler-based Natural Rubber composites. Increment in clearance of two roll mill during addition of rubber additives along with rubber of reduced the shearing force resulted in less dispersive and distributive mixing and stagnant points due to band formation on roll surface compared to intermix where compound movement had no stagnation point and long wings pushed material axially and two nogs pushed material in other chamber. Compared to two roll mill samples, the compound reached every point of the mixing chamber for best homogeneity, reducing cure time and improving stress-strain and volume resistivity.

Al-Ti-C (CNTs) master alloys improve room temperature and high-temperature mechanical properties of ZL205A alloy

The insufficient high-temperature properties of Al-Cu alloys represent a significant obstacle to their further development. The use of master alloy refiners can enhance the mechanical properties while refining the grains. This paper describes the preparation and characterization of Al-Ti-C (CNTs) master alloys containing submicron TiC particles through the aluminum melt reaction method, utilizing graphite powders (GPs) and (CNTs) as carbon sources,respectively.The effects of these two types of intermediate alloys on the microstructures and high-temperature mechanical properties of the ZL205A alloy were investigated at varying additive amounts. The results indicate that the Al-Ti-C (CNTs) master alloys contain TiC particles measuring up to 183 nm and 480 nm, respectively, with the Al-Ti-CNTs demonstrating a superior effect on the refinement of the ZL205A alloy. The optimal mechanical properties were achieved upon the addition of 0.3 wt% of the master alloy to the ZL205A alloy. The mechanical properties improved from 341.53 MPa (yield strength), 371.68 MPa (tensile strength), and 3.3 % elongation without the addition of master alloys to 413.20 MPa, 471.82 MPa, and 11.2 % with the addition of Al-Ti-CNTs and to 440.85 MPa, 492.61 MPa, and 10.8 % with the addition of Al-Ti-C, respectively.At a high temperature of 300°C, the mechanical properties of the ZL205A alloy improved from 144.0 MPa and 10.8 % (Al-Ti-C) to 174.87 MPa and 11.2 %, and 195.1 MPa and 13.8 % (Al-Ti-CNTs). The TiC particles generated in situ under a different carbon sources demonstrated distinct mechanisms in the grain refinement of the ZL205A alloy. TiC (GPa) with a larger size primarily impeded the further growth of grains, while TiC (CNTs) promoted the formation of crystalline nuclei and heterogeneous nucleation sites, thereby achieving grain refinement. Large-sized TiC particles prepared using graphite as the carbon source hindered further grain growth, whereas TiC produced using carbon nanotubes promoted the formation of nuclei and heterogeneous nucleation sites, resulting in grain refinement. In addition, both types of TiC particles contribute to the densification and strengthening of the ZL205A alloy through fine grain strengthening, precipitation strengthening, Orowan strengthening, load transfer strengthening, the pinning effect, and thermal mismatch strengthening. However,TiC(CNTs) exhibits a greater contribution to strength due to its high quantity and small size.

Sustainable production of graphene oxide with ascorbic acid reduction: characterization and insights

In this study, graphene oxide (GO) was synthesized from graphite powder using KMnO4 and a concentrated mixture of H2SO4/H3PO4. The obtained GO was subsequently reduced using ascorbic acid. The ratios of H2SO4 to H3PO4 and KMnO4 to graphite powder were kept constant. The synthesized GO and reduced graphene oxide (rGO) were evaluated using UV-visible spectroscopy, FT-IR spectroscopy, XRD, SEM, and EDX. The findings showed that processing graphite powder with KMnO4 at 60 °C for 12 hours resulted in a high degree of oxidation and minimal defects. Furthermore, ascorbic acid, an alternative to highly toxic hydrazine, aided in eliminating oxygen-containing functional groups in the rGO. This study focuses on the properties of GO produced using the improved Hummer's method, and the changes observed after chemical reduction.

The improvement of dry sliding tribological properties by designing nano-primary cementite in bainitic/martensitic matrix microstructure in hypereutectoid PM components

The production of nano-sized primary cementite in bainite/martensite matrix (NCBM) microstructure was designed to improve the dry sliding wear properties of high carbon PM parts. A different heat treatment cycle was carried out for the production of novel the NCBM microstructure. High purity iron powder 1.5 wt%. natural graphite powder was added and it was compacted in the form of a dry sliding wear test specimen in a mold and sintered at 1200 °C in a pure Ar gas atmosphere. The novel NCBM microstructure in the PM material was produced by quenching at 950 °C, then annealing at 600 °C for 12 min, then quickly cooling from 730 °C to 250 °C in a salt bath and keeping it isothermal for 100 s. The friction coefficient of materials with NCBM microstructure was less than other samples. It was found that while the wear coefficient were higher in the tempered martensitic microstructure sample having higher hardness, they were less than in the sample having bainitic/martensitic microstructure with similar hardness.

Preparation of Ti3AlC2 MAX-phase as a precursor material using industrial waste carbon flex for MXene synthesis

MAX phase represents a new class of solids that combine some of the best attributes of metals and ceramics, exhibiting unusual, mechanical, electrical, and thermal properties. Further Ti3AlC2 MAX phase is exfoliated to create 2D nanosheet material called Ti3C2 MXene and both have unmatched qualities for difficult and unusual applications. The Ti3AlC2 MAX phase powder is the precursor material to synthesize the Ti3C2 MXene nanosheets, but the cost effective synthesis of Ti3AlC2 powder is still a challenging problem which ultimately decides the quality and cost of Ti3C2 MXene. In this paper, we present the novel synthesis of Ti3AlC2 MAX phase using carbon flex generated as an industrial waste from aluminum, Steel, and other metal industries in composites production. To the best of our knowledge we first time novely report the use of Industrial waste carbon flex as a base carbon material to partially replace commercial graphitic carbon powder in Ti3C2 synthesis. The effect of adding carbon flexes precursor to synthesizing Ti3AlC2 MAX phase solving many current challenges. In present work we comparatively report the physicochemical study of the MAX phase synthesized with three different carbon precursors to establish the role of industrial waste carbon flex in the quantitative growth of Ti3C2MXene as the final product.

Synergistic effect of nickel and graphite powders on the thermoelectric properties of ultra-high-performance concrete containing steel fibers and MWCNTs

The study investigates the influence of multi-walled carbon nanotubes (MWCNTs) and conductive powders, namely nickel powder (NP) and graphite powder (GP), on the mechanical and thermoelectric properties of ultra-high-performance concrete (UHPC). Flowability tests indicate that the addition of MWCNTs and conductive powders affects the flow diameter, with higher concentrations resulting in decreased flowability. Thermalgravimetric analysis and Fourier transform infrared spectroscopy reveal that the enhancement of the hydration reaction by 0.1 % MWCNTs in UHPC reaches saturation at this concentration. Pore structure analysis demonstrates a reduction in porosity and a denser structure upon the addition of 0.1 % MWCNTs. Mechanical tests indicate that the incorporation of 0.1 % MWCNTs enhances compressive and tensile strengths, whereas the introduction of 0.3 % MWCNTs diminishes the mechanical performance. Moreover, the electrical conductivity and thermoelectric effect are enhanced with the addition of MWCNTs and conductive powders. However, a decline in thermoelectric effect is observed when 0.3 % MWCNTs are added, although the conductivity remained high. The optimal thermoelectric performance is achieved with the combination of 0.3 % MWCNTs and 5 % NP, yielding a maximum power factor (PF) of 2148.2 μW/m·K2 and a figure of merit (ZT) of 4.9 × 10⁻7.

Experimental comparison of the effects of the two designed probes for exfoliation of graphene by sonication.

In the present research, comparative simulation and experimental investigation were carried out for two different probes to improve the efficiency and quality of few-layer graphene utilizing liquid-phase exfoliation. Two differently designed shaped probes are fabricated for this study, i.e., a simple probe and a stepped probe. The acoustic pressure distribution in the vessel is simulated for both probes at different output powers. In the experiment, both probes exfoliate graphite powder in a mixture of deionized water and ethanol. Different sonication times and output power were studied for different pulse modes. The graphene layers were characterized using Ultraviolet-visible spectroscopy (UV‒Vis), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Raman Microscope. The simulation shows that the total displacement on the tip of the stepped probe is 5.7% greater than that of the simple probe. Also, the pressure difference produced by the stepped probe is 9.15 × 106 pa compared to the pressure difference of the simple probe which is 8.23 × 106 pa. Consequently, the stepped probe was more effective in exfoliating graphene. The experimental results show that the absorbance peak in the stepped probe is approximately 32% greater than the absorbance peak in the simple probe with the same output power. Also, the graphene with better quality is produced with the stepped probe compared to the simple probe, which verifies the simulation findings. Additionally, the optimum output power, pulse duration, and sonication time to produce graphene with less time and energy consumption are obtained. The best graphene flakes were obtained via sonication with a pulse duration of 0.7 s, an output power of 282 W, and a sonication time of 45 min using a stepped probe. UV-Vis., SEM and TEM analysis show increases in quantity and quality of the exfoliated flakes. These results are approved by the peak ratio of I2D/IG around 1 in Raman spectra revealed the production of the few-layer graphene by the simple probe and the bilayer graphene by the stepped probe. So, this method is suitable for the production of graphene flakes from graphite in suitable quantity and quality.

Effect of carbon content on the microstructure and mechanical properties of Ti2AlC/TiAl composites with network architecture

In the present work, using pre-alloyed Ti-48Al-2Cr-2Nb powders and graphite powders with different contents as raw materials, the Ti2AlC/TiAl composites with network architecture were fabricated by spark plasma sintering (SPS). The effect of carbon content on the microstructure and mechanical properties of Ti2AlC/TiAl composites with network architecture was investigated. The results have shown that with the increasing carbon content from 0.5 wt% to 2 wt%, the network continuity of Ti2AlC particles gradually transforms from semi-continuous network into quasi-continuous and nearly-continuous network, and the network thickness transforms from 5 to 10 μm into 10∼15 μm and 20∼30 μm. The Ti2AlC/TiAl composite with 1 wt% C shows a better balance of compressive strength and ductility, which the room-temperature compressive strength is 2051 MPa and compressive strain is 30.9 %. The quasi-continuous network structural Ti2AlC particles in Ti2AlC/TiAl composite with 1 wt% C could effectively deplete the crack propagation energy by deflecting the crack, and passivate the crack to hinder further propagation, which facilitates the improvement of the strength and ductility in the Ti2AlC/TiAl composite.

Room-temperature superconductivity in carbons – a mini review

The search for room-temperature superconductivity in carbons is gathering momentum because it has a long history, impressive track record, clear advancement route, and theoretical backup. The report of a suspected Josephson current in Al-C-Al sandwiches at room temperature, published in Nature 50 years ago, led to the report of a voltage in nano-graphite films believed to mark the reverse Josephson effect. The report on oxygen-doped diamonds led to full-blown superconductivity in boron-doped diamonds. The reports on highly oriented pyrolytic graphite (HOPG) and water-treated graphite powder led to the claim of a current running by itself for 50 days in a ring of HOPG soaked with alkane at room temperature. It also led to a claim of a current running for 1,000 seconds in a ring of graphene soaked in hexane. The carbons are amicable to intercalation chemistry, electrostatic carrier doping, and surface-proving techniques to promote an increase in carrier density, metallization, and applicability of the Ashcroft proposal. Consequently, the high Debye temperatures (1,670, 2,230 and 2,500 K in graphene, diamond and HOPG) may be sufficient to underwrite superconductivity at T∼300 K in carbons, provided the phonon-exchange factor, λ, is around 3 to mark strong enough interactions between electrons and phonons.

Synthesis and field emission characterization of La-doped SiC nanowires using graphite powder as carbon source

Lanthanum (La)-doped SiC nanowires (NMs) were synthesized via a carbon thermal reduction process using different graphite powders, while milled Si-SiO2 mixed powders were employed as the silicon source. The identification of the products as β-SiC were supported by Select-area electron diffraction (SAED) and X-ray diffraction (XRD) analysis. The field emission results demonstrated that the turn-on field reached a minimum value of approximately 2.3 V/μm when the graphite content ranged from 2.5 g–3 g. The product exhibited higher density at this stage, accompanied by an increase in nanowire diameter and a tendency toward straightness. The energy spectrum analysis revealed a significant increase in the lanthanum content within the nanowires, with the atomic percentage rising from 0.05 to 0.26–0.27. The synergistic effect of morphology and La improved the field emission performance of the product. The findings may offer valuable insights for enhancing the field emission performance of one-dimensional nanomaterials.

Adsorption Desulfurization of Simulated Diesel Fuel Using Graphene Oxide

Graphene oxide (GO) was synthesized from graphite powder by the improved Hammers method and used for the adsorption of organosulfur compound (dibenzothiophene, DBT) from model diesel fuel. FT-IR spectroscopy, X-ray diffraction, SEM, EDX, and BET were used to characterize the GO. Several factors, such as solution pH, initial DBT concentration, adsorption contact time, adsorption temperature, and adsorbent dosage were used to test the DBT removal efficiency. The results show that the maximum removal was 96.4% at pH = 5, initial solution concentration of 200 ppm, adsorption time of 45 min, temperature of 45C and adsorbent dosage of 0.4 g/25 mL.

3D printed oxygen gas sensor with a Pt-nanoparticles decorated N-doped carbon catalyst and an amine-polymer composited ionic liquid gel electrolyte

A 3D-printed electrochemical oxygen gas sensor was developed using a Pt nanoparticle-decorated N-doped carbon (PtNC) catalyst and an ionic liquid gel electrolyte incorporated with polyethyleneimine. At first, N-doped carbon particles were synthesized hydrothermally, followed by the decoration of a tiny amount of Pt nanoparticles using a microwave reactor. The working electrode was printed with a composite of high-impact polystyrene (HIPs), graphite powder (Gr), and a PtNC catalyst (HIPs/Gr/PtNC), then counter and reference electrodes were separately printed without the PtNC catalyst. The sensing materials were characterized using various analytical methods, including SEM, XPS, Raman, ICP-AES, CV, and EIS. Prior to detecting oxygen gas, the 3D sensor surface was pretreated with potential cycling in an acidic solution. Additionally, a composite gel electrolyte was prepared by incorporating polyethyleneimine into an ionic liquid, which was then coated onto the sensor surface to enhance sensitivity and ensure long-term stability. The analytical parameters using the final sensor were optimized in terms of Pt contents, 3D-printing polymer type, and ionic liquid gel concentration. The amperometric measurements demonstrated a wide dynamic range from 0.1 % to 100 % with the detection limit of 0.13 ± 0.05 % at a 90 % response time of 3.6 ± 0.4 s. To validate the reliability of the proposed sensor, the measurement of O2 content was performed for room air and standard oxygen gas, revealing reliable and stable results for six months.

Sustainable Fabrication of Graphene Oxide Cathodes from Graphite of Failed Commercial Li-Ion Batteries for High-Performance Aqueous Zn-Ion Batteries.

The need for revamping spent graphite (SG) from battery waste of commercial lithium-ion batteries and employing it as a source for the synthesis of graphene oxide (GO) is focused. Thus, this work emphasizes the study of GO sheets, synthesized via modified Hummer's method from spent graphite (SG-GO) as cathodes for an aqueous zinc ion battery (AZIB) system, for the first time in literature. For comparison, graphene oxide is also synthesized using commercial graphite powder, its structural and morphological properties are analyzed with SG-GO. The coin cell AZIB device is fabricated for both the GOs and the electrochemical performances revealed that SG-GO portrayed an enhanced charge capacity of 270 mAh g-1 at 0.1 A g-1 in 3m ZnSO4 in comparison to GO which delivered ≈198 mAh g-1 at the same current density of 0.1 A g-1. The long-run cycling analysis of SG-GO elucidated the capacity retention of 77.3% at 1 A g-1 even after 1000 cycles. Moreover, the performance of SG-GO is inspected in different electrolyte systems and the suitable electrolyte underwent concentration variation studies to figure out the capability of the system in storing Zn2+ ions which is found to be more in 3M ZnSO4 electrolyte.

Self-Sensing Potential of Metashale Geopolymer Mortars with Carbon Fiber/Graphite Powder Admixtures

Multifunctional building materials with self-sensing capability have great potential for civil engineering applications. The self-sensing capability of typically calcium aluminosilicate matrices of cementitious or geopolymer materials is adopted by admixing electrically conductive admixtures in an amount that ensures optimal electrical properties and their proportionality to mechanical loading. The paper aims to evaluate the self-sensing capability of 4 metashale geopolymer mortars with graphite powder (GP) and carbon fibers (CF) in different ratios, including MGF 5/0, MGF 4.5/0.5, MGF 4/1, and MGF 3/0. The 4-probe measurements at 21 V DC input voltage on (100 × 100 × 100) mm3 samples with embedded copper-grid electrodes evaluate the gauge factor, which corresponds to the monitored changes in electrical resistivity. Despite the limitations of DC measurements, the self-sensing capability is observed for all the mixtures. The most promising response to dynamic loading with an FCR of 0.018%, is observed for the MGF 4.5/0.5 sample.