Carbon Powder Research Articles

Engineering Partially Oxidized Gold via Oleylamine Modifier as a High-Performance Anode Catalyst in a Direct Borohydride Fuel Cell.

Direct borohydride fuel cell (DBFC) is considered a promising energy storage device due to its high theoretical cell voltage and energy density. For DBFC, an Au catalyst has been used as an anode for achieving an ideal eight-electron reaction. However, the poor activity of the Au catalyst for borohydride oxidation reaction (BOR) limits its large-scale application because of the weak BH4- adsorption. We found, by density functional theory calculations, that the adsorption of BH4- on the oxidized Au surface is stronger than that on the metallic Au surface, which can promote the process of the oxidation of BH4- to *BH3 during the BOR. Here, we reported an oleylamine-modified partially oxidized Au supported on carbon powder (AuC-OLA) with a stable oxidation state. The obtained catalyst delivered a high peak power density of 143 mW/cm2, which is 2 times higher than that of a commercial 40% AuC (Pretemek). The in situ Fourier transform infrared studies showed that the activity of AuC-OLA for BOR is ascribed to the enhanced adsorption for BH4- on the partially oxidized Au surface. These findings will promote the reasonable design of efficient Au electrocatalysts for DBFCs.

Development of phase change eco-composite materials from eggshell waste

ABSTRACT The consumption of eggshell powder (ES) as an affluent source of calcium carbonate (CaCO3) can efficiently solve both ecological and financial interest. The use of eggshell waste in eco-composite materials (ECPCMs) is an attempt to reduce waste's negative effects. Eco-composite powders of polyethylene glycol (PEG) and calcium carbonate (CaCO3) were obtained by mechanical grinding. Compression molding was used to produce plates from the ground powders. FTIR spectroscopy and X-ray diffraction analysis showed that the ECPCMs were physically combined and the crystallinity of the two components was affected. According to TGA, the thermal stability of ECPCMs was improved, thanks to the use of eggshell waste powder. On the other hand, the results of the DSC showed that ECPCM with the addition of 90 wt% of PEG in the mixture provides excellent thermal stability and high energy storage density. In light of its high latent heat storage capacity of 156.1 J/g as well as its ability to prevent PEG exudation. Significant enhancement in melting-solidification time shows an improvement in Thermal Energy Storage (TES) response time by adding ES to the PCM. The obtained results indicate a good potential for industrially applied ECPCMs.

Synthesis of chromium carbide powder by vacuum-free electric arc plasma method

Chromium carbide powders were synthesized by vacuum-free electric arc method using pure chromium and carbon powder as starting components. The powders obtained in the experimental series were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), laser diffraction and differential thermal analysis. In the experiments, electrical parameters were recorded, and the thermal field generated in the reaction zone was measured using an infrared camera and tungsten‑rhenium thermocouples. The study results show the feasibility of plasma arc discharge synthesis of chromium carbide compounds Cr3C2 and Cr7C3 within 60 s at current intensity of 200 A. SEM analysis of the resulting powder shows that it consists of acute-angled particles of ∼9 to ∼50 μm in size. An updated design of the discharge circuit employed in the study significantly increases the purity of the final product. Vacuum-free electric arc synthesis of chromium carbide has been studied for the first time.

Core-shell carbon@Ni2(CO3)(OH)2 particles as advanced cathode materials for hybrid supercapacitor: The key role of carbon for enhanced electrochemical properties

Three-dimensional porous Ni2(CO3)(OH)2 compounds were grown on carbon nanopowder using a facile hydrothermal method for the production of core-shell carbon@Ni2(CO3)(OH)2 compounds. This work successfully overcame the shortcomings related to the low electrical conductivity and poor electrical stability caused by the presence of hollows in the Ni2(CO3)(OH)2 structure. The hollow spaces were filled with carbon powder, which acted as a seed material, yielding an ideal electrode material with a large specific surface area, high electrical conductivity, and good stability. A Ni2(CO3)(OH)2 electrode containing 50 mg of carbon powder could store more energy than a Ni2(CO3)(OH)2 electrode without carbon seed materials. The Ni2(CO3)(OH)2 electrode comprising 50 mg of carbon powder has a considerably high specific capacity (181.7 mAh g−1 at 3 A g−1) and excellent cycling stability (77.9 % capacity retention after 5000 cycles), which is 1.5 times higher than that of the Ni2(CO3)(OH)2 electrode without carbon powder. Moreover, an asymmetric supercapacitor using Ni2(CO3)(OH)2 containing 50 mg of carbon powder as the positive electrode and graphene as the negative electrode exhibits a high energy density of 34.2 Wh kg−1 and a power density of 176.1 W kg−1 at a current density of 2 A g−1. Using a combination of carbon and a Ni2(CO3)(OH)2 nanowire compound to increase the electrochemical property and specific surface area, respectively, a suitable synergistic effect can be obtained, which may pave the way for efficient electrode design for high-performance supercapacitors.

Introducing Ionic Transport Islands in Graphite Anode towards Fast-Charging Lithium-Ion Batteries

The development of lithium-ion batteries (LIBs) possessing excellent fast charging performance is particularly important for expanding the worldwide application market of LIBs. However, the grievous growth of lithium dendrites during high rate charging and discharging process occurring on the surface of the anode material still restricts the development of commercial fast charging LIBs, which raises capacity deterioration and even enormous safety risks. Herein, we developed simple physical mixing of active carbon (AC) powder into graphite negative slurry to generate the hybrid fast charging anode (called AS anode), which can realize unprecedented fast charging capability whether at room temperature or low temperature, along with greatly improved capacity retention cycling at high 2 C rate. Importantly, the density functional theory calculation and combined characterizations including in situ electrochemical confocal system spectroscopy and lithium ion (Li+) diffusion coefficient analysis can decipher that AC particles with rapid Li+ diffusion and adsorption can act as ion transport islands in graphite electrode to accelerate the transport process of lithium ion inside the whole negative electrode, leading to the faster charging performance. This work not only promotes the development of anode construction with fast charging capability for LIBs, but also deciphers the ion transport mechanism inside the electrode.

Edible Gelatin and Cosmetic Activated Carbon Powder as Biodegradable and Replaceable Materials in the Production of Supercapacitors

Environmental pollution is currently one of the most worrying factors that endangers human health. Therefore, attempts are being made to reduce it by various means. One of the most important sources of pollution in terms of the current RoHS and REACH directives is the pollution caused by the use of chemical products for the production of sources for the storage and generation of electricity. The aim of this article is therefore to develop supercapacitors made of biodegradable materials and to investigate their electrical performance. Among the materials used to make these electrodes, activated carbon was identified as the main material and different combinations of gelatin, calligraphy ink and glycerol were used as the binders. The electrolyte consists of a hydrogel based on gelatin, NaCl 20 wt% solution and glycerol. In the context of this research, the electrolyte, which has the consistency of a gel, fulfills the dual function of the separator in the structure of the manufactured cells. Due to its structure, the electrolyte has good mechanical properties and can easily block the contact between the two electrodes. Most of the materials used for the production of supercapacitor cells are interchangeable materials, which are mainly used in other application fields such as the food or cosmetics industries, but were also successfully used for the investigations carried out in this research. Thus, remarkable results were recorded regarding a specific capacitance between 101.46 F/g and 233.26 F/g and an energy density between 3.52 Wh/kg and 8.09 Wh/kg, with a slightly lower power density between 66.66 W/kg and 85.76 W/kg for the manufactured supercapacitors.

Substantially boosted energy density of NiCoMn layered double hydroxides with nanocrystalline-amorphous domains

To promote the energy density (E) of the hybrid asymmetric supercapacitance (ASC) device, both anode and cathode materials are crucial. The multi-component layered double hydroxides (LDH) as anode materials boost a surprisingly supercapacitance, while the functions of dual-phase nanodomains induced by multi-constituents on the electrochemical reactions are still puzzled and need to be explored. In this work, Ni1Co1Mnx (Ni/Co/Mn = 1/1/x) LDH microspheres are developed, characterizing by quantum-sized nanocrystals embedded in amorphous matrix modulated via Mn doping. The specific capacities (C) of Ni1Co1Mn1.5 reach up to 5750 at 1 A g−1 and 5300 F g−1 at 10 A g−1, exceeding four times of 1367 (1 A g−1) and 1133 F g−1 (10 A g−1) of the Ni1Co1Mn0 counterpart. To break through the upper limit of the traditional active cardon cathode, bamboo-derived porous carbon (BPC) powders are produced from green raw resource by two stages calcination to increase the C. The assembled ASC cell with Ni1Co1Mn1.5 as an anode and BPC as a cathode possesses a large E of 97.8 Wh kg−1 at a power density (P) of 749.2 W kg−1. An exceptional sustainability of Ni1Co1Mn1.5//BPC device is attained with 91.4 % retention after 8000 cycles at a large charging current of 10 A g−1. The insights of Mn-regulated transition of nanocrystal-amorphous microstructure and the enhanced energy storage performance are explored.

Shungite Paste Electrodes: Basic Characterization and Initial Examples of Applicability in Electroanalysis

This article introduces a new type of carbon paste electrode prepared from black raw shungite. In powdered form, this carbonaceous material was mixed with several nonpolar binders. The resulting shungite pastes were microscopically and electrochemically characterized. Mixtures of several pasting liquids with different contents of shungite powder were tested to select the optimal composition and compared with other types of carbon paste-based electrodes made of graphite and glassy carbon powder. In terms of physical and mechanical properties, shungite paste electrodes (ShPEs) formed a composite mass being like dense pastes from glassy carbon microspheres, having harder consistency than that of traditional graphitic carbon pastes. The respective electrochemical measurements with ShPEs were based on cyclic voltammetry of ferri-/ferro-cyanide redox pairs, allowing us to evaluate some typical parameters such as electrochemically active surface area, double-layer capacitance, potential range in the working media given, heterogeneous rate constant, charge-transfer coefficient, exchange current density, and open-circuit potential. The whole study with ShPEs was then completed with three different examples of possible electroanalytical applications, confirming that the carbon paste-like configuration with powdered shungite represents an environmentally friendly (green) and low-cost electrode material with good stability in mixed aqueous-organic mixtures, and hence with interesting prospects in electroanalysis of biologically active organic compounds. It seems that similar analytical parameters of the already established variants of carbon paste electrodes can also be expected for their shungite analogues.

Moisture Sensitivity of Hot Mix Asphalt Modified with Micronized Calcium Carbonate

Moisture sensitivity in an HMA refers to the loss of mastic cohesion and durability between the bitumen and aggregates due to water presence. Various methods exist to mitigate this type of sensitivity, with one of the most important approaches being the incorporation of anti-stripping agents into either the bitumen or aggregate materials. Based on this premise, the current study investigates the impact of using micronized calcium carbonate powder (MCCP or CaCo3) as a modifier for bitumen on moisture sensitivity in HMA. Three types of aggregates with different mineralogical properties (limestone, granite, and quartzite), and PG 64–16 bitumen (along with 2% and 4% MCCP based on the mass of the bitumen) were utilized. The modified Lottman test was performed under 1 to 5 freeze-thaw cycles while measuring surface free energy (SFE) elements for both bitumens and aggregates with Wilhelmy Plate (WP) and Universal Sorption Device (USD), respectively. The results of the moisture sensitivity test on the asphalt mixtures used in this study demonstrate that the addition of MCCP in the modified samples has led to a reduction in the sensitivity of the asphalt mixtures, particularly in multiple freeze-thaw cycles, compared to the control samples. Furthermore, findings from SFE analysis demonstrated that MCCP enhanced cohesion free energy (CFE) which subsequently reduced rupture probability within the bitumen membrane. Additionally, it improved adhesion between acidic aggregates susceptible to moisture-induced sensitivity and bitumens.

Sorbents utilizing h-BN micro- and nanoparticles for efficient antibiotic removal in wastewater treatment

Currently, there is a high demand for novel sorbents for wastewater treatment. Nanostructured materials are often considered as more promising sorbents compared to their microsized counterparts, which, however, requires experimental verification. In this work, two types of h-BN materials (micro- and nanosized) are compared as candidates for antibiotic sorption. The initial h-BN was in the form of microsized pellets. Nanostructurued h-BN was obtained by high energy ball milling of the initial powder. The effect of ball milling on the microstructure, morphology, chemical composition and surface chemical state was investigated by SEM, TEM, STEM, EDX, XRD, XPS, FTIR and BET techniques. Adsorption properties were studied on samples in the form of pellets and powders. Activated carbon powder was used as a reference material. The antibiotic adsorption process was studied using tetracycline and linezolid. The influence of the h-BN structure on the adsorption characteristics was elucidated using DFT calculations.

Effect of pore-forming agent on degradation of phenol by iron tailings based porous ceramics

In order to realize the resource utilization of solid waste and the treatment of phenol wastewater in China, a new porous ceramic granules (PCG) with the function of degrading phenol wastewater was prepared by using titanium-containing blast furnace slag, iron tailings and fly ash as raw materials, which realized the sustainable development of "treating waste with waste". The effects of different pore forming agents on the structure, morphology, ionic state of PCG samples and the adsorption behavior of phenol in aqueous solution were investigated. The results show that the change of pore forming agent has no obvious change on the crystal structure. When carbon powder (CP) and starch (SH) are used as pore forming agents, the internal pore structure is relatively dense and less porous, and it is not easy to form liquid channels. When ammonia bicarbonate (NH) is used as pore-forming agents, the internal pore structure is very developed and has many three-dimensional pore structures. Under the conditions of PH 2, phenol concentration 10 mg/L and solid-liquid ratio 3 g/L, TOC removal rates of CP-PCG, SH-PCG and NH-PCG samples after 72 h adsorption reaction were 39.10 %, 14.00 % and 93.29 %, respectively. In addition, the surface functional groups, hydrogen bonds and π-π interactions of PCG samples may be involved in the adsorption of phenol. This work not only provides a low-cost, environmentally friendly and simple technology for phenol-containing wastewater treatment, but also provides a new idea for the effective use of solid waste resources.

Friendly Environmental Strategies to Recycle Zinc-Carbon Batteries for Excellent Gel Polymer Electrolyte (PVA-ZnSO4-H2SO4) and Carbon Materials for Symmetrical Solid-State Supercapacitors.

In this report, we introduce a novel idea to prepare a redox additive in a gel polymer electrolyte system of PVA-ZnSO4-H2SO4 based on zinc-carbon battery recycling. Here, zinc cans from spent zinc-carbon batteries are dissolved completely in 1 M H2SO4 to obtain a redox additive in an aqueous electrolyte of ZnSO4-H2SO4. Moreover, carbon nanoparticles and graphene nanosheets were synthesized from carbon rod and carbon powder from spent zinc-carbon batteries by only one step of washing and electrochemical exfoliation, respectively, which have good electrochemical capability. The three-electrode system using a ZnSO4-H2SO4 electrolyte with carbon nanoparticles and graphene nanosheets as working electrodes shows high electrochemical adaptability, which points out its promising application in supercapacitor devices. Thus, the symmetrical solid-state supercapacitor devices based on the sandwich structure of graphene nanosheets/PVA-ZnSO4-H2SO4/graphene nanosheets illustrated the highest energy density of 39.17 W h kg-1 at a power density of 1700 W kg-1. While symmetrical devices based on carbon nanoparticles/PVA-ZnSO4-H2SO4/carbon nanoparticles exhibited a maximum energy density of 35.65 W h kg-1 at a power density of 1700 W kg-1. Moreover, these devices illustrate strong durability after 5000 cycles, with approximately 90.2% and 73.1% remaining, respectively. These results provide a promising strategy for almost completely recycling zinc-carbon batteries, one of the most popular dry batteries.

Restoring historical buildings using additive manufacturing

This paper considers using additive manufacturing in restoration projects. This research proof that Polyblend Calcium Carbonate (Grout) powder can be used as a building material on the ZPrinter 450 Binder Jetting 3D printer. Such material has promising applications in restoring historical structures. Using statistically designed experiments, this research investigated the effect of the layer thicknesses, binder saturation, curing solution, and curing time on 3D-printed tiles. The breaking strength, deviation from the nominal dimension, and surface roughness were measured as the key quality characteristics of printed tiles. The results were confirmed using additional runs. Research findings could be instrumental in offering unprecedented capabilities to preserve and revitalize historical structures and architectural treasures. These innovative research efforts will be extremely instrumental in the field of 3D printed customized tiles, façades restoration, and decorative calligraphy tiles.

Experimental investigation of concrete incorporating untreated agricultural waste and calcium carbonate powder

Experimental investigation of concrete incorporating untreated agricultural waste and calcium carbonate powder

High-pressure high-temperature synthesis and characterization of B10C

The boron-rich boron carbide materials have been traditionally synthesized by adding boron powder to B4C material and subjecting it to hot pressing sintering for materials composition containing 8.8–20 at. % carbon in boron (composition range of B10.4C to B4C). Our study explores a synthesis route for B10C starting from high-purity boron and carbon and direct conversion under high pressure and high temperature (HPHT) conditions of 2000 °C and 6–8 GPa. Synthesis was verified via x-ray diffraction analysis, showing the conversion of the high-purity boron and carbon powder mixture into a hexagonal B10C structure (R-3m space group) with lattice parameters of a = b = 5.6115 Å and c = 12.197 Å. The concentration of boron was measured through x-ray photoelectron spectroscopy, confirming the B10C ratio. The measured nanoindentation mean hardness of B10C was 40 GPa. Raman spectroscopy of the HPHT synthesized sample shows characteristic vibrational breathing modes of boron icosahedron and an additional intense band at a vibrational frequency of 380 cm−1. This Raman band, which appears notably weaker in earlier studies and B4C samples, is assigned to the linear chain of B–B–B and attributed to the maximal incorporation of boron within the hexagonal structure.

Immobilization of zirconium-modified activated carbon in an alginate matrix for the removal of atrazine: Preparation, performances and mechanisms

As an organic herbicide widely used in agriculture, atrazine has the characteristics of environmental persistence, high mobility and long half-life period, posing potential risks to the ecological environment. The materials commonly used to remove atrazine are powdered activated carbon and its modified materials, which have problems such as difficulty in recycling and secondary contamination. In order to solve the above problems, in this study, a new functional material EI-Zr@AC was prepared by immobilizing zirconium-modified activated carbon powder (Zr@AC) in an alginate matrix via the embedding immobilization (EI) technique, and was employed for removing atrazine in water. At the optimal preparation conditions of 2.5 % sodium alginate, 4.0 % CaCl2, 1.0 % Zr@AC and 2.0 % bentonite, the prepared EI-Zr@AC beads had the characteristics of high porosity, dense reticulation, and a large number of functional groups with optimal mechanical strength and mass transfer properties. When solution pH 3.0, temperature 25°C, and EI-Zr@AC dosage of 16 g/L, the removal efficiency of atrazine by EI-Zr@AC was 91.9 %. It showed that the atrazine removal by EI-Zr@AC was mainly the chemisorption and multimolecular layer adsorption. In addition, the EI-Zr@AC could be recycled after simple recycling method, and the removal of atrazine at 5.0 mg/L by the beads was still 55.5 % after five cycles, and the structure of the beads remained intact and Zr ion leaching rate was very low. The results showed that EI-Zr@AC was a kind of environmental remediation material with high application value.

Experimental and Numerical Investigation of Fracture Energy and Size Effect in Carbon Powder Reinforced PLA Parts Manufactured by Fused Deposition Modeling

Experimental and Numerical Investigation of Fracture Energy and Size Effect in Carbon Powder Reinforced PLA Parts Manufactured by Fused Deposition Modeling

SYNTHESIS AND CHARACTERIZATION OF ACTIVATED CARBON PREPARED FROM RICE HUSK BY PHYSICS-CHEMICAL ACTIVATION

Activated carbon is an amorphous carbon material predominantly composed of free carbon atoms with high adsorption capacity. The amorphous structure in activated carbon affects its adsorption capacity; the higher the percentage of amorphous carbon, the greater the adsorption capacity of the activated carbon. Activated carbon can be obtained from rice husk waste containing 30-40% C in cellulose, hemicellulose, and lignin. Therefore, this study was conducted to observe activated carbon's phases, morphology, elemental composition, and particle size. Activated carbon was synthesized using a physics-chemical activation method, which began with washing the rice husk samples, followed by air drying, carbonizing into charcoal, and grinding it finely. The rice husk charcoal powder was then physically activated at a temperature of 500℃. The physically activated product was then chemically activated using 6M HCl with a charcoal-to-activator ratio of 1:10 (m/V), stirred at 250 rpm for 1 hour, and then allowed to settle for 24 hours. It was then washed and dried to produce activated carbon powder. XRD test results showed diffraction peaks at 2θ = 22.23° without sharp or pointed peaks, indicating that the activated carbon has an amorphous structure. SEM test results showed the morphology of rice husk-activated carbon with spherical particle shapes and a particle size distribution of 20-70 nm. EDX test results showed that the rice husk activated carbon is predominantly composed of C, O, and Si with respective percentages of 54.31%, 40.04%, and 2.49%.

Pulsed laser fragmentation synthesis of carbon quantum dots (CQDs) as fluorescent probes in non-enzymatic glucose detection

Pulsed laser fragmentation in liquid (PLFL) is one of the synthesis routes for producing high-purity carbon quantum dots (CQDs) with less toxic by-products in a straightforward system. The limited literature regarding the application of PLFL-synthesized CQDs motivated this study to exploit them as fluorescent probes in glucose sensing. The design of a fluorescent-based non-enzymatic glucose sensor was achieved by implementing CQDs and 3-aminophenylboronic acid (APBA) as fluorescent probes and glucose receptors, respectively. The CQDs were fabricated by PLFL through an Nd:YAG nanosecond laser, starting from the carbon powder dispersion in ethanol. Then, a laser-assisted post-modification process with oxidizing acid was implemented to produce water-dispersible CQDs for easy functionalization. Functionalizing these CQDs with APBA (CQDs-APBA) resulted in a blue-shifted fluorescence emission with a 35% quantum yield and high photostability. The CQDs-APBA exhibited a turn-off response at increasing glucose concentrations. This method offers good sensitivity with a linear detection range of glucose with a concentration of 0.165 to 8 mM and a detection limit of 165 µM. The applicability of this sensor to real analytes such as saliva obtained a satisfactory result with good reproducibility. This work proves that CQDs synthesized from PLFL can also be an alternative fluorescent probe for fluorescent-based sensing applications.

Production of Porous Biochar from Cowdung and its Application

Porous activated carbon (PAC) powder is prepared from solid bio-waste - cow dung samples (CD). UV- Spectroscopy confirms the absorption rate of activated porous biochar at different concentration solutions(in ppm).The activation process is carried out by phosphoric acid and sodium hydroxide treatment followed by calcination at different temperature condition. XRD pattern confirms the amorphous phase formation with graphitic nature for different precursor utilization. SEM analysis shows the uniform and hierarchical porous network formation and aggregated particle with tiny. X- ray analysis confirms the formation of graphitic carbon and porous morphology for sample activated at increased calcination temperature. The elemental composition of as prepared carbon samples is determined by SEM and confirms the formation major carbon content existence. The obtained product is observed for the dye removal process wherein the specific amount of PAC is added to the Methylene Blue(MB) dye solutions and the absorption rate is observed through uv-spectroscopy.