Carbon Black Matrix Research Articles

Photo-enhanced electrocatalytic methanol oxidation of carbon black-modified Pt and Mo-based oxide for acidic and basic solutions

Pt nanoparticles were electrodeposited on a molybdenum-based oxide (e.g., molybdenum oxide (MoO3) and bismuth molybdate (Bi2MoO6)) modified carbon black (CB) support to study the enhancement of methanol oxidation in acidic and basic solutions with the assistance of visible light illumination. Morphology studies showed that Bi2MoO6 nanoparticles were initially anchored on the CB matrix with round 2.2 nm Pt nanoparticle decoration, resulting in a large extension of the specific active catalytic surface area (SSA) for Pt/Bi2MoO6/CB. It was found that the Pt/Bi2MoO6/CB composite catalyst offered the highest electrocatalytic activity with visible light support, showing 2 (in an acidic solution) and 18 (in a basic solution) times higher reactivity than the electrodeposited Pt/CB. Moreover, the electrocatalytic activity and stability of the prepared catalyst toward methanol oxidation with the aid of visible light were noticeably improved in both acidic and basic solutions, and the oxidation improvement was greatest in basic solutions. Therefore, the improved oxidation performance of the prepared catalysts was mostly a result of the combination of both photocatalytic and electrocatalytic procedures on Pt-based catalysts with metal oxides, resulting in enhanced catalytic activity and stability for the oxidation of methanol and CO under visible light.

Azide-Assisted Growth of Copper Nanostructures and Their Application as a Carbon Supported Catalyst in Two-Step Three-Component Azide-Alkyne Cycloadditions.

Copper nanostructures were obtained from the reduction of Cu(I) under mild conditions in ethanol/water using sodium-l-ascorbate and sodium azide while performing an amination reaction. When the halobenzene substrate was reacted in the presence of a bulk carbon black (CB) support, clustered copper sub-micrometer particles (SMPs) and microparticles (MPs) form. The growth conditions of the MPs were optimized, and the supported nanostructures were isolated and characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, thermogravimetry, and inductively-coupled plasma mass spectrometry. The particles are mobile and supported within the CB matrix and proved to be active catalysts in the azide-alkyne cycloaddition (CuAAC). The catalytic competency of the particles was assessed in a two-step three-component azide-alkyne cycloaddition of benzyl bromide, sodium azide, and phenylacetylene as a model reaction. The reaction conditions were optimized, and the optimized conditions were applied for the synthesis of triazole compounds with varying levels of functionalization. The recyclability of the catalysts was investigated, depletion modes were discussed, and the conditions were fine-tuned to reach good recyclability. This demonstrates the broader applicability of the SMPs/MPs as CuAAC-catalyst and its limitations.

β-Mo2C Nanoparticles Produced by Carburization of Molybdenum Oxides with Carbon Black under Microwave Irradiation for Electrocatalytic Hydrogen Evolution Reaction

The synthesis of electrochemically active β-Mo2C nanoparticles for hydrogen production was achieved by a fast and energy-efficient microwave-assisted carburization process from molybdenum oxides and carbon black. With the use of microwave-based production methods, we aim to reduce the long-time high-temperature treatments and the use of hazardous gases often seen in traditional molybdenum carbide synthesis processes. In our process, carbon black not only serves as a carbon source but also as a susceptor (microwave absorber) and conductive substrate. The irradiation power, reaction time, and Mo:C ratio were optimized to achieve the highest electrocatalytic performance toward hydrogen production in an acidic electrolyte. A complete transformation of MoO3 to β-Mo2C nanoparticles and an additional graphitization of the carbon black matrix were achieved at 1000 W, 600 s, and Mo:C ratio above 1:7.5. Under these conditions, the optimized composite exhibited an excellent HER performance (η10 = 156 mV, Tafel slope of 53 mV·dec–1) and large turnover frequency per active site (3.09 H2·s–1 at an overpotential of 200 mV), making it among the most efficient non-noble-metal catalysts. The excellent activity was achieved thanks to the abundance of β-Mo2C nanoparticles, the intimate nanoparticle-substrate interface, and enhanced electron transport toward the carbon black matrix. We also investigated the flexibility of the synthesis method by adding additional Fe or V as secondary transition metals, as well as the effect of the substrate.

High efficient carbon coated TiO2 electrode for ultra-capacitor applications

The present paper reports the investigation of structural, optical, chemical bonding, and electrical properties of the carbon black (CB)/TiO2 composite synthesized via the standard sol–gel method. The structural and morphological properties have been investigated using x-ray diffraction and also field emission scanning electron microscopy to confirm the formation of the nanocomposite. The electrochemical performance of the two-electrode symmetric fabricated supercapacitor (SC) has been examined by complex impedance spectroscopy, cyclic voltammetry, and galvanostatic charge–discharge (GCD). The electrode CT15 (15% TiO2 in CB matrix) shows a high specific capacitance of 236 F g−1 at scan rate 10 mV s−1. The GCD illustrates good specific capacitance retention of 90.3% after 10 000 cycles and with energy density and power density values as 22 Wh kg−1 and 625 kW kg−1 respectively (at 1 A g−1) in the voltage window of 1.2 V. The CT15 electrode cell demonstrates superior electrochemical performance as compared to other electrodes. Electrochemical impedance spectroscopy (EIS) demonstrates the capacitive behaviour of the composite electrode with a low value of resistance. The SC cell having optimum performance has been chosen to demonstrate the glowing red light emitting diode. A mechanism has also been proposed based on received data parameters to validate the SC performance.

Bifunctional iron-phtalocyanine metal–organic framework catalyst for ORR, OER and rechargeable zinc–air battery

Exploring non-noble metal and high-activity electrocatalysts through a simple and controllable protocol remains a great challenge for oxygen reduction reaction (ORR) and zinc–air batteries. Herein, we developed a melt polymerization strategy to synthesize iron-polyphthalocyanine (FePPc) metallic–organic frameworks (MOFs) over the carbon black matrix (FePPc@CB). Through non-covalent $$\uppi$$ – $$\uppi$$ interactions, FePPc molecules can anchor on carbon matrix, thus facilitating the electron transfer process and stabilizing the systems. Owing to abundant free electrons and atomically MN4 catalytic sites in the macrocycle structure, FePPc@CB exhibits excellent oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) electrocatalytic activity. The FePPc@CB also delivers excellent performances for liquid and flexible all-solid-state batteries compared to that of commercial Pt/C, making it a promising ORR/OER electrocatalyst.

Approaching Reactive KFePO4 Phase for Potassium Storage by Adopting an Advanced Design Strategy

AbstractPristine KFePO4 is electrochemically inactive towards potassium, which suggests that K+ ion migration is unfavorable in the KFePO4 structure. Therefore, it is a challenge to create a reactive structure of KFePO4 towards reversible potassium insertion/extraction. In this study, we have fabricated reactive KFePO4 phase by adopting high‐energy ball milling technique where tiny nanoparticles (∼1.0‐1.5 nm) of KFePO4 are created and embedded in the Super P carbon black matrix, which provides conductivity and helps to stabilize the electrode structure. The combination of nano‐sizing and the conductive matrix appears to activate electrochemical reactivity. The obtained carbon incorporated KFePO4 material appears to be amorphous. The electrode produces an average operational potential of ∼2.5 V (vs K+/K) with high capacity retention of 90 mAh g−1. It is anticipated that this work could pave the way for further studies on cathodes and generate huge attention to the role of ball milling and particle size control on electrochemical activity of KFePO4 materials for the development of PIBs.

The properties of elastomeric composites based on three network precursors

The powder recycled rubber (PRR) can be used as a filler and a modifier for elastomeric materials and asphalt. Composites based on elastomers and recycled rubber powders are a serious challenge for the environment. The main goal of this paper was to study the effect of rubber powder on the mechanical properties of elastomeric composites based on three precursors of the network. Triple blends were prepared using non‐polar natural rubber (NR), polyisoprene rubber (BR), and styrene‐butadiene rubber (SBR) (mass ratio 40/40/20). In all rubber compounds, the carbon black (CB)/PRR mass ratio is constant (60). Samples were prepared using two roll mill. The characteristics of hardening (optimum cure time, scorch time, minimum and maximum torque) of rubber mixtures were tested. Tensile strength, modulus at 100% elongation and elongation at break are decreasing with PRR ratio is increasing. It is due to poor adhesion of PRR into NR/BR/SBR/CB matrix. The thermal degradation temperature shifts to a higher temperature up to 5 phr of PRR in NR/BR/SBR/CB rubber blends. Fourier‐transform infrared spectra of NR/BR/SBR/CB/PRR samples show that the absorption bands shifted 7–15 cm−1 to higher wavenumbers and confirmed rubber–filler interaction. Morphology was assessed by scanning electron microscopy. POLYM. COMPOS., 40:1307–1314, 2019. © 2018 Society of Plastics Engineers

Densely Packed, Ultra Small SnO Nanoparticles for Enhanced Activity and Selectivity in Electrochemical CO2 Reduction

AbstractControlling the selectivity in electrochemical CO2 reduction is an unsolved challenge. While tin (Sn) has emerged as a promising non‐precious catalyst for CO2 electroreduction, most Sn‐based catalysts produce formate as the major product, which is less desirable than CO in terms of separation and further use. Tin monoxide (SnO) nanoparticles supported on carbon black were synthesized and assembled and their application in CO2 reduction was studied. Remarkably high selectivity and partial current densities for CO formation were obtained using these SnO nanoparticles compared to other Sn catalysts. The high activity is attributed to the ultra‐small size of the nanoparticles (2.6 nm), while the high selectivity is attributed to a local pH effect arising from the dense packing of nanoparticles in the conductive carbon black matrix.

Densely Packed, Ultra Small SnO Nanoparticles for Enhanced Activity and Selectivity in Electrochemical CO2 Reduction

Controlling the selectivity in electrochemical CO2 reduction is an unsolved challenge. While tin (Sn) has emerged as a promising non-precious catalyst for CO2 electroreduction, most Sn-based catalysts produce formate as the major product, which is less desirable than CO in terms of separation and further use. Tin monoxide (SnO) nanoparticles supported on carbon black were synthesized and assembled and their application in CO2 reduction was studied. Remarkably high selectivity and partial current densities for CO formation were obtained using these SnO nanoparticles compared to other Sn catalysts. The high activity is attributed to the ultra-small size of the nanoparticles (2.6 nm), while the high selectivity is attributed to a local pH effect arising from the dense packing of nanoparticles in the conductive carbon black matrix.

Facile Synthesis of WS2 Nanosheets–Carbon Composites Anodes for Sodium and Lithium Ion Batteries

AbstractWS2 nanosheets–carbon composites (WS2/C) were synthesized through a simple two‐step process including ball‐milling and sulfidation. When applied as anode materials for sodium‐ion batteries and lithium‐ion batteries, WS2/C composites deliver a high reversible sodium storage capacity of 270 mA h g−1 at 100 mA g−1 and a high reversible lithium storage capacity of 322 mA h g−1 at 200 mA g−1 after 100 cycles. The improved electrochemical performance of WS2/C compared with the bare WS2 can be attributed to the synergic effects between WS2 and Super P carbon black matrix, which can offer a beneficial conductivity environment for electron transfer and accommodate stress from the volume change during cycling.

Dispersion of Nanocrystalline Fe3O4 within Composite Electrodes: Insights on Battery-Related Electrochemistry.

Aggregation of nanosized materials in composite lithium-ion-battery electrodes can be a significant factor influencing electrochemical behavior. In this study, aggregation was controlled in magnetite, Fe3O4, composite electrodes via oleic acid capping and subsequent dispersion in a carbon black matrix. A heat treatment process was effective in the removal of the oleic acid capping agent while preserving a high degree of Fe3O4 dispersion. Electrochemical testing showed that Fe3O4 dispersion is initially beneficial in delivering a higher functional capacity, in agreement with continuum model simulations. However, increased capacity fade upon extended cycling was observed for the dispersed Fe3O4 composites relative to the aggregated Fe3O4 composites. X-ray absorption spectroscopy measurements of electrodes post cycling indicated that the dispersed Fe3O4 electrodes are more oxidized in the discharged state, consistent with reduced reversibility compared with the aggregated sample. Higher charge-transfer resistance for the dispersed sample after cycling suggests increased surface-film formation on the dispersed, high-surface-area nanocrystalline Fe3O4 compared to the aggregated materials. This study provides insight into the specific effects of aggregation on electrochemistry through a multiscale view of mechanisms for magnetite composite electrodes.

Bioelectricity-generating behavior of a chemically modified carbon black anode in microbial fuel cells

The poor stability of the current output in microbial fuel cells (MFCs) inhibits its development and application on a large scale. In this work, a carbon black (CB) MFC anode was chemically activated using HNO3 and KOH as pretreatment agents at low temperature, and further modification was made by Fe3O4 addition to the host CB matrix. The enhanced anodic capacitance contributes to a steady power output with neither overshoot nor undershoot below 1.1 F/cm2. This resulted from the introduction of oxygen(nitrogen)-associated functionalities and the improvement of the surface wettability by the activation treatment. The chemical modification of a CB anode provides a feasible way to optimize power production and anodic capacitance in MFCs.

Enhanced lithium storage in ZnFe2O4–C nanocomposite produced by a low-energy ball milling

Preparation of novel nanocomposite structure of ZnFe2O4–C is achieved by combining a sol–gel and a low energy ball milling method. The crucial feature of the composite's structure is that sol–gel synthesised ZnFe2O4 nanoparticles are dispersed and attached uniformly along the chains of Super P Li™ carbon black matrix by adopting a low energy ball milling. The composite ZnFe2O4–C electrodes are capable of delivering a very stable reversible capacity of 681 mAh g−1 (96% retention of the calculated theoretical capacity of ∼710 mAh g−1) at 0.1 C after 100 cycles with a remarkable Coulombic efficiency (82%) improvement in the first cycle. The rate capability of the composite is significantly improved and obtained capacity was as high as 702 at 0.1, 648 at 0.5, 582 at 1, 547 at 2 and 469 mAh g−1 at 4 C (2.85 A g−1), respectively. When cell is returned to 0.1 C, the capacity recovery was still ∼98%. Overall, the electrochemical performance (in terms of cycling stability, high rate capability, and capacity retention) is outstanding and much better than those of the related reported works. Therefore, our smart electrode design enables ZnFe2O4–C sample to be a high quality anode material for lithium-ion batteries.

Influence of Convective Drying Parameters on Electrode Performance and Physical Electrode Properties

As the need for nonpolluting individual mobility is rising, the production processes of lithium-ion batteries are gaining more and more attention. Although a lot of research for new battery materials or even for alternative battery technologies is done, the state of the art production process for large scale automotive lithium-ion batteries is still not completely understood. To get as close as possible to the theoretical performances of the used materials, an optimized process which includes a deep understanding of its influences on electrode structure and in the end on cell performance is essential. For this reason the drying process as one of the key-process-steps in the electrode production process is examined.Since drying fixes the coating structure by evaporation of the solvent, the sedimentation of active material particles and the formation of the binder and carbon black matrix is influenced in a crucial way. In the present work some of the various drying parameters such as air temperature, outlet speed, air flow rate and residence time are varied and their influence on electrode structure is examined. A pilot-plant continuous convective dryer with three individual adjustable segments and a total length of six meters is basis of these investigations.In order to analyze the resulting electrode structure measurements like mercury porosimetry (to determine the porediameter distribution of the coating), electrode conductivity (to describe the network of the conductive additives) and adhesion force measurements (to characterize the binder distribution) were carried out. As an example, a strong impact on the coating’s adhesion force to the current collector with increasing drying intensity (or faster solvent evaporation, respectively) and coating thickness could be found and explained by changes in electrode’s structure. Deeper insights in the processes affecting electrode structure can be obtained by determination of the electrochemical cell performance, thus allowing the establishment of process-structure-property relations.Besides offline measurements to determine the electrode structure the drying process itself is monitored online by detecting the shift from constant rate drying period to falling rate period via infrared temperature sensors which measure the surface temperature of the coating. If the coating speed is kept constant the point of drying period change can be detected within a shorter distance from the dryer inlet when the air temperature is increased (see Fig. 1). The period change is identified for different drying parameters and electrode thicknesses as thicker electrodes tend to show a more distinct influence by the drying process.In summary recent investigations show that electrode properties (e.g. adhesion force) resulting from solvent evaporation and structure fixation are clearly dependent on drying parameters and thus enabling a way for enhancing the battery’s performance.

Crystallization of tin chloride as a promising pseudocapacitor electrode

In the present work, we designed an in situ crystallization method for tin chloride salts pseudocapacitors, that is, a SnCl4·5H2O or SnCl2·2H2O electrode in aqueous KOH electrolyte. After undergoing coupled chemical/electrochemical crystallization and Faradaic redox reactions, highly active SnO/Sn colloids were in situ crystallized within the carbon black matrix; such an electrode configuration can result in the fast transfer of ions/electrons and efficiently utilize the active tin cations in the salt electrode, thus high specific capacitance can be obtained. The SnCl4 electrode can deliver ultrahigh specific capacitance of 1592 F g−1 at a current density of 1 A g−1 and a potential range of 0.42 V, which is the highest value among the reported tin-based supercapacitors. Our designed tin chloride electrode/alkaline electrolyte system can offer critical insights into the rational design of the next generation of high-performance supercapacitor devices.

Copper/carbon core shell nanoparticles as additive for natural fiber/wood plastic blends

Copper/carbon core/shell nanoparticles (CCCSNs) recently have been introduced as an industrial material. In this paper, composites based on high density polyethylene (HDPE), bamboo fiber, CCCSNs, and coupling agent (MAPE) were prepared by melt compounding. The influence of CCCSN content on the resulting composites’ mechanical, biological resistance, and thermal properties was investigated. It was found that CCCSNs within the carbon black matrix were processed well with bamboo fiber-plastic blends through mixing and injection molding. The materials enhanced composite strength and modulus-related properties. Composites with CCCSNs and natural fibers reduced heat capacity and thermal diffusivity. Composites with CCCSN materials also enhanced termite and mold performance. Thus, the material can be used as additive for plastics and other polymers to modify strength properties, biological resistance (e.g., mold and stain), and thermal conductivity properties.

Three-dimensional nano MnO2/CB composite and its application for electrochemical capacitor

A three-dimensional nanostructure composed of birnessite MnO2 and carbon black (CB) was built via a quite simple co-precipitation method at room temperature. The natural porous construction of conductive CB granules provided enough sites for MnO2 deposition. The as-prepared composite showed that dispersive MnO2 nanowires were directly crystallized on the surface of CB matrix, which was believed to be beneficial to its electrochemical performance. The further investigation of cyclic voltammetry (CV) in 1M Na2SO4 confirmed the inference, which showed good symmetrical rectangular shape, and the specific capacitance was calculated about 186F/g at a scan rate of 2mV/s. After 1000cycles of CV at 10mV/s, the initial capacitance was maintained at about 91%, indicating that the designed structure had benefit to high electrochemical stability.

Elastomer composites based on improved fumed silica and carbon black. Advantages of mixed reinforcing systems

The combination of reinforcing fillers is one of the most promising tendencies in elastomer reinforcement, where a synergic effect between them is desired. Up to now, the use of mixed fillers has been focused on the preparation of dual fillers based on a complex synthesis process where silica particles are in situ generated in a carbon black matrix. In this paper, mixed filler systems are prepared following a straightforward methodology, where carbon black is gradually and partially substituted by modified fumed silica. The presence of reinforcing fillers with different surface energies significantly decreases filler networking, reducing the non-linear viscoelastic response of the composites. The hybrid reinforcing systems prepared were easily incorporated into the elastomer matrix by conventional methods in rubber technology. Physical and dynamic responses of the elastomeric composites were characterized in order to find the optimum mixed system combination. Filler–rubber interface was characterized combining 1H low field DQ (Double Quantum) NMR spectroscopy and equilibrium swelling experiments.

Novel single-layer gas diffusion layer based on PTFE/carbon black composite for proton exchange membrane fuel cell

A series of poly(tetrafluoroethylene)/carbon black composite-based single-layer gas diffusion layers (PTFE/CB-GDLs) for proton exchange membrane fuel cell (PEMFC) was successfully prepared from carbon black and un-sintered PTFE, which included powder resin and colloidal dispersion, by a simple inexpensive method. The scanning electron micrographs of PTFE/CB-GDLs indicated that the PTFE resins were homogeneously dispersed in the carbon black matrix and showed a microporous layer (MPL)-like structure. The as-prepared PTFE/CB-GDLs exhibited good mechanical property, high gas permeability, and sufficient water repellency. The best current density obtained from the PEMFC with the single-layer PTFE/CB-GDL was 1.27 and 0.42 A cm −2 for H 2/O 2 and H 2/air system, respectively.

The effect of the matrix on the electro-catalytic properties of methanol tolerant oxygen reduction catalysts based on ruthenium-chalcogenides

In this work, a catalyst based on nanostructured Ru x Mo y Se z compounds was prepared by thermolysis of their carbonyl compounds in organic solvents. Evaluation of the catalytic activity was carried out via cyclic voltammetry on carbon paper. Synthesized catalyst was supported either by carbon black (Vulcan XC-72) or by polyaniline coated carbon black. The oxygen reduction activity and methanol tolerance of both electrodes was compared with commercial E-TEK 20% Pt–C electrode and polyaniline coated commercial E-TEK 20% Pt–C electrode. Characterisation of the catalysts was made using XRD and SEM. An important increase in the oxygen reduction reaction rate was observed using polyaniline coated carbon black matrix.