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In spite of significant efforts to investigate the ability of hydrogenated and fluorinated graphene to conduct heat, little research has focused particularly upon their other thermal properties, such as thermal contraction and heat capacity, which have implications for the development of thermal nanotechnology. In an attempt to determine these thermal properties, a few experiments have been carried out, with rather conflicting results. In the present study, calculations were performed using molecular dynamics to investigate the thermal properties of graphane and fluorographene and especially the phenomena involved. The thermal expansion coefficients and heat capacities of the two-dimensional materials were determined at different temperatures. The results indicated that graphane is thermally contracted more significantly than graphene. The calculated molar heat capacity at constant volume is about 25.00 J/(mol·K) for graphene and about 29.26 J/(mol·K) for graphane. The specific heat capacity of fluorographene is always lower than that of graphane. A negative relationship does exist between the binding energy and the temperature.

The results of experimental modeling of glassy carbon production from high-pressure supercritical fluid (SCF) in the C–O–H system at a temperature of 800°C and pressures of 500 – 1000 atm are presented. Acomprehensive characterization of the carbon material is presented, using the data from CHNS-O analysis, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), x-ray and electron diffraction, infrared and multiwavelength Raman spectroscopy (Raman). In light of the characteristics and outcomes of the comparison with industrial glassy carbon, the synthesized carbon material was classified as a glassy substance. The findings of the experimental studies provide evidence for potentially different mechanisms of formation and, consequently, polygenicity of the glassy state of carbon. The material obtained through a radically distinct production method (polycondensation) may possess distinctive surface and bulk properties. [ABSTRACT FROM AUTHOR]

The electrochemical conversion of CO2 into high value-added carbon materials by molten salt electrolysis offers a promising solution for reducing carbon dioxide emissions. This study focuses on investigating the influence of molten salt composition on the structure of CO2 direct electroreduction carbon products in chloride molten salt systems. Using CaO as a CO2 absorber, the adsorption principle of CO2 in LiCl-CaCl2, LiCl-CaCl2-NaCl and LiCl-CaCl2-KCl molten salts was discussed, and the reasons for the different morphologies and structures of carbon products were analyzed, and it was found that the electrolytic efficiency of the whole process exceeded 85%. Furthermore, cathode products are analyzed through Scanning Electron Microscope (SEM), X-Ray Diffractometer (XRD), Thermal Gravimetric Analyzer (TGA), Raman Spectra and Fourier Transform Infrared (FTIR) techniques with a focus on the content and morphology of carbon elements. It was observed that the carbon content in the carbon powder produced by molten salt electrochemical method exceeded 99%, with most carbon products obtained from electrolysis in the Li-Ca chloride molten salt system being in the form of carbon nanotubes. In contrast, the Li-Ca-K chloride system yielded carbon nanospheres, while a mixture was found in the Li-Ca-Na chloride system. Therefore, experimental results demonstrate that altering the composition of the system allows for obtaining the desired product size and morphology. This research presents a pathway to convert atmospheric CO2 into high value-added carbon products. [ABSTRACT FROM AUTHOR]

The increased consumption of strategic metals has led to the necessity to search for new and non-traditional sources of mineral raw materials. All this has resulted in the necessity to develop and justify new technological solutions for the integrated recovery of strategic metals and the associated production of high-purity carbon materials. The purpose of this work was to substantiate the possibility of obtaining high-purity shungite carbon materials and metal-bearing concentrate containing valuable metals from shungite rocks using high-gradient magnetic separation and flotation with the use of an apolar collector emulsion in a frother solution. The conducted investigations using a complex of analysis methods allowed us to justify the obtaining of a metal-bearing concentrate containing iron, titanium, copper and zirconium and carbon material of high purity. By using high-gradient magnetic separation, we obtained a metal-bearing concentrate with a yield of 17.35% and a total metal content of 63.61% broken down as follows: Fe2O3 recovery of 87.66%, TiO2 recovery of 56.03%, CuO recovery of 72.52% and ZrO2 recovery of 54.42%. By using flotation, we obtained a shungite carbon concentrate with a yield of 31.41%, made of 88.15% carbon with a content and recovery of 88.09% and a sulphur content of 0.084%. The conducted studies showed the possibility of using classical beneficiation operations in the processing of non-traditional mineral raw materials to obtain commercial products. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries (SIBs) are considered one of the most promising candidate technologies for future large-scale energy storage systems due to their highly abundant sodium and advantages similar to lithium-ion batteries (LIBs). However, the successful commercialization of SIBs relies heavily on the development of high-performance anode materials. Carbon-based materials are considered the ideal choice for SIBs negative electrode because of their abundant resources, cost-effectiveness, environmental friendliness, and excellent electrochemical properties. In this paper, the research progress of carbon anode materials in SIBs is reviewed. The application status of different carbon anode materials and the storage mechanism of four types of sodium ions in the hard carbon structure are systematically introduced and discussed. From the aspects of heteroatom doping, pore structure design, and layer spacing adjustment, this paper introduces the latest research progress in improving the sodium storage performance of carbon-based anode materials and summarizes the strategies for enhancing this performance. Finally, the future development directions and challenges of high-performance carbon-based anode materials are discussed and prospected, providing a feasible reference scheme for the rapid development of SIBs. [ABSTRACT FROM AUTHOR]

Selective conversion of biomass into targeted molecules like polyols, especially, from cellulosic compounds, is being widely investigated as a sustainable process to produce biodiesel and bio-additives. The known process involves two steps, namely hydrolysis and hydrogenation. Thus, it requires two different catalytic materials or bifunctional catalysts. In this context, the present work reports a new catalytic approach based on the use of tandem catalysts, consisting of the combination of an acid solid catalyst (active for hydrolysis) and a supported metal catalyst (active for hydrogenation). Two different functionalized activated carbons and the resin Amberlyst 15 have been tested as solid acid catalysts, and Ru nanoparticles supported on the original activated carbon (SA) are the metal catalyst part of the tandem. All the tested tandem catalysts exhibited higher activity than the supported Ru catalyst did. The highest cellulose conversion and selectivity to sorbitol (70% and 86%, respectively) have been obtained over a novel tandem catalyst, which resulted from a physical mixture between a sulfuric acid modified SA carbon (SASu) and Ru loaded SA (Ru/SA), leading to a tandem catalyst (Ru/SA+SASu). This novel-designed tandem catalyst is reusable. Based on tandem catalysts with a solid-solid system combination, the adopted novel-designed catalytic approach is cost-efficient and sustainable, and can be considered promising for the green production of high-added-value chemicals.

Flexible energy storage devices have attracted wide attention as a key technology restricting the vigorous development of wearable electronic products. However, the practical application of flexible batteries faces great challenges, including the lack of good mechanical toughness of battery component materials and excellent adhesion between components, resulting in battery performance degradation or failure when subjected to different types of deformation. It is imperative to develop flexible batteries that can withstand deformation under different conditions and maintain stable battery performance. This paper reviews the latest research progress of flexible lithium batteries, from the research and development of new flexible battery materials, advanced preparation processes, and typical flexible structure design. First, the types of key component materials and corresponding modification technologies for flexible batteries are emphasized, mainly including carbon-based materials with flexibility, lithium anode materials, and solid-state electrolyte materials. In addition, the application of typical flexible structural designs (buckling, spiral, and origami) in flexible batteries is clarified, such as 3D printing and electrospinning, as well as advanced fabrication techniques commonly used in flexible materials and battery components. Finally, the limitations and coping strategies in the practical application of flexible lithium batteries are discussed, which provides new ideas for future research. [ABSTRACT FROM AUTHOR]

Selective conversion of biomass into targeted molecules like polyols, especially, from cellulosic compounds, is being widely investigated as a sustainable process to produce biodiesel and bioadditives. The known process involves two steps, namely hydrolysis and hydrogenation. Thus, it requires two different catalytic materials or bifunctional catalysts. In this context, the present work reports a new catalytic approach based on the use of tandem catalysts, consisting of the combination of an acid solid catalyst (active for hydrolysis) and a supported metal catalyst (active for hydrogenation). Two different functionalized activated carbons and the resin Amberlyst 15 have been tested as solid acid catalysts, and Ru nanoparticles supported on the original activated carbon (SA) are the metal catalyst part of the tandem. All the tested tandem catalysts exhibited higher activity than the supported Ru catalyst did. The highest cellulose conversion and selectivity to sorbitol (70% and 86%, respectively) have been obtained over a novel tandem catalyst, which resulted from a physical mixture between a sulfuric acid modified SA carbon (SASu) and Ru loaded SA (Ru/SA), leading to a tandem catalyst (Ru/SA + SASu). This novel-designed tandem catalyst is reusable. Based on tandem catalysts with a solid-solid system combination, the adopted novel-designed catalytic approach is cost-efficient and sustainable, and can be considered promising for the green production of high-added-value chemicals. [ABSTRACT FROM AUTHOR]

It is difficult for carbonaceous materials to combine a large specific surface area with flexibility. Here, a flexible all-carbon nanoarchitecture based on the in situ growth of nanoporous graphene within "skeletal-capillary" carbon nanotube (CNT) networks has been achieved by a chemical vapor deposition (CVD) process. Multi-path long-range conductivity is established, and the porous graphene provides a large specific surface area for charge storage. The flexibility of the films allows them to be directly used as binder-free electrodes for supercapacitors. Since the polymeric binders are saved, the supercapacitors exhibit a higher overall storage density. [ABSTRACT FROM AUTHOR]

Amorphous carbon is recognized as an excellent lubricating material; however, its tribological properties are significantly influenced by humidity. To elucidate the mechanism underlying this humidity dependence and to propose a novel enhancement method, we investigated and compared the tribological properties of hydrogenated amorphous carbon (a-C:H) and amorphous carbon/gold (a-C/Au) composite films. First, the friction coefficient of these carbon films under different humidity conditions was tested using a rotational ball-on-disk tribometer. Subsequently, we analyzed the morphology and structure of the sliding interface employing optical microscopy (OM), Raman spectroscopy, transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). Finally, first-principle calculations were carried out to calculate the adsorption energy of water molecules on different surfaces. The results indicate that the friction coefficient of a-C:H film and the area of transfer film increase with the increase of humidity. This phenomenon can be attributed to the fact that water molecules enhance the interaction between the a-C:H film and steel counterfaces. Notably, in contrast, the friction coefficient of a-C/Au film demonstrates low sensitivity to humidity due to the formation of an Au transfer film that exhibits weak interaction with water molecules. These findings provide a promising strategy for developing environment-adaptive amorphous carbon films and play an important role in promoting the development of intelligent lubricating film. [ABSTRACT FROM AUTHOR]

Organic pollutants entering water bodies lead to severe water pollution, posing a threat to human health. The activation of persulfate advanced oxidation processes using carbon materials derived from MOFs as substrates can efficiently treat wastewater contaminated with organic pollutants. This research uses NH2-MIL-101(Fe) as a substrate, doped with Fe2+ and Co2+, to prepare Fe/Co-CNs through a one-step carbonization method. The surface morphology, pore structure, and chemical composition of Fe/Co-CNs were investigated using characterization techniques such as XRD, SEM, TEM, XPS, FT-IR, BET, and Raman. A comparative study was conducted on the performance of catalysts with different Fe/Co ratios in activating PMS for the degradation of organic pollutants, as well as the effects of various influencing factors (the dosage of Fe/Co-CNs, the amount of peroxymonosulfate (PMS), the initial pH of the solution, the TC concentration, and inorganic anions) on the catalyst's activation of persulfate for TC degradation. Through radical quenching experiments and post-degradation XPS analysis, the active radicals in the FeCo-CNs/PMS system were investigated to explain the possible mechanism of TC degradation in the Fe/Co-CNs/PMS system. The results indicate that Fe/Co-CNs-2 (with a Co2+ doping amount of 20%) achieves a degradation rate of 93.34% for TC (tetracycline hydrochloride) within 30 min when activating PMS, outperforming other Co2+ doping amounts. In addition, singlet oxygen (1O2) is the main reactive species in the reaction system. [ABSTRACT FROM AUTHOR]

The increasing demand for chip heat dissipation has led to more challenges in designing and regulating thermal interface materials with high performance. It is crucial to have a comprehensive understanding of the design and mechanism of thermal conduction path built by thermal conductive fillers. Diamond, in particular, has garnered significant attention. In this study, we constructed three-dimensional particle random distribution models of diamond/silicone rubber composites based on the morphological characteristics of common industrial-grade diamond. We also conducted experiments with different morphologies and filling amounts of diamonds in silicone rubber to better understand the effect of diamond fillers on the thermal conductivity of the composites. From the model simulation, thermal conductivity and actual LED temperature rise tests, the study reveals that broken single-crystal diamond with lamellae or rod-like with large aspect ratio or radius-thickness ratio is easier to form thermal transfer paths than spherical or spherical-like diamond under low filling content. Ultimately, the silicone rubber composites filled with intact hexa-octahedral single-crystal diamonds achieve the highest thermal conductivity as a result of the formation of more comprehensive three-dimensional heat dissipation network (1.357 W/(m K), 80 wt.%). In comparison with silicone rubber composites filled with spherical Al2O3 (0.995 W/(m K), 80wt.%) and pure silicone rubber (0.21 W/(m K), 80 wt.%), the thermal conductivity increases by 36% and 546%, respectively. The revelation of the construction law and mechanism of different diamond morphologies on the thermal conduction path of thermal interface materials provides a theoretical basis for broadening the application of diamond in the design of thermal interface materials. [ABSTRACT FROM AUTHOR]

This study presents a novel Fe-CNs-P/S carbon composite material, synthesized by doping elements P and S into NH2-MIL-101 (Fe) using the carbonization method. The material's application in sustainable water treatment was evaluated, focusing on its effectiveness in activating persulfate for pollutant degradation. The research thoroughly investigates the synthesis process, structural characteristics, and performance in degrading pollutants. The results indicate that Fe-CNs-P/S-5 with 50% P and S co-doping is higher than that of other samples, where the degradation rate of TC in 30 min is as high as 98.11% under the optimum conditions, that is temperature at 25 °C, 0.05 g/L of catalyst concentration, and 0.2 g/L of PMS concentration. The composite material demonstrates robust versatility and stability, maintaining high degradation efficiency across multiple organic pollutants, with no significant reduction in catalytic performance after four cycles. Furthermore, the free radical quenching experiments display that the singlet oxygen 1O2 is the main active species. It is demonstrated that the doping of P and S play a role in the enhancement of PMS activation over the Fe-CNs-P/S catalyst. This material demonstrates remarkable efficacy in treating a range of organic contaminants and exhibits excellent reusability, presenting a promising approach for enhancing sustainability in water treatment applications. [ABSTRACT FROM AUTHOR]

Currently, one of the topical directions in the field of production and application of graphene-like nanostructures is the use of renewable natural raw materials, which have unlimited resources for an economically efficient large-scale yield of a product with environmental safety. In this regard, we present the production of graphene oxide (GO) from a renewable natural raw material of plant biomass, birch activated carbon (BAC), and a comparison of the obtained physicochemical, mechanical, and electrical properties of birch activated carbon–graphene oxide (BAC–GO) and graphite–graphene oxide (G–GO) synthesized from the initial materials, BAC and graphite (G). Results obtained from this study confirm the successful oxidation of BAC, which correlates well with the physical–chemical dates of the G–GO and BAC–GO samples. Change in data after the oxidation of graphite and BAC was facilitated by the structure of the starting materials and, presumably, the location and content of functional oxygen-containing groups in the G–GO and BAC–GO chains. Based on the results, the application of a cost-effective, eco-friendly colloidal solution of nanodispersed BAC–GO from a plant biomass-based high-quality resource for producing large-scale nanostructured graphene is validated which has potential applicability in nanoelectronics, medicine, and other fields. [ABSTRACT FROM AUTHOR]

In this study, carbon materials with different dimensions, including the typical one-dimensional (1D) carbon nanotube (CNT), two-dimensional (2D) graphene (GF), and three-dimensional (3D) activated carbon (AC), were investigated as a support for Pt catalysts for the selective hydrogenation of 3,4-dichloronitrobenzene (3,4-DCNB) to 3,4-dichloroaniline (3,4-DCAN). Notably, the Pt/CNT catalyst with the lowest dimension exhibited the best conversion of 3,4-DCNB under mild reaction conditions, followed by Pt/GF. Comprehensive characterizations, including XRD, TEM, XPS, and in situ CO DRIFTS, reveal that the dimension of carbon supports plays an important role in the particle size and electronic properties of Pt species, consequently affecting the catalytic performances of Pt catalysts. According to the results, electron-deficient Pt particles with small sizes are more favorable for the hydrogenation of 3,4-DCNB to 3,4-DCAN. In addition, dynamic tests and in situ DRIFTS of 3,4-DCNB indicated that the carbonaceous supports will largely influence the adsorption and activation capacity of the Pt catalysts, so that Pt loaded on CNT and GF are superior to that on the AC. We believe this study will provide good guidance for designing efficient carbon-supported metal catalysts for selective hydrogenation. [ABSTRACT FROM AUTHOR]

Rare earth elements (REEs), comprising seventeen metallic elements, including lanthanides, scandium, and yttrium, are indispensable for modern technological industries due to their unique properties. However, their supply is critically risky for the European Union, with 95% of global production concentrated in China, Brazil, Vietnam, Russia, India, and Australia. This mini-review examines the adsorption of REEs onto pyrolytic carbon-based materials as a sustainable recovery method from secondary raw materials. The review covers different types of carbon-based adsorbents used in several research works, such as activated carbon, chars, and biochar, and discusses their adsorption mechanisms and influencing factors. Comparative analyses of adsorption capacities highlight the significance of surface area and functionalization in enhancing adsorption efficiency. Despite promising results, the variability in adsorption performance due to experimental conditions and the scarcity of real-world application studies are noticed. This review underscores the need for further research using real e-waste leachates to validate the practical applicability of pyrolytic carbon-based adsorbents for REEs' recovery, aiming for an economically and environmentally sustainable solution. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries (SIBs) have been proposed as a potential substitute for commercial lithium-ion batteries due to their excellent storage performance and cost-effectiveness. However, due to the substantial radius of sodium ions, there is an urgent need to develop anode materials with exemplary electrochemical characteristics, thereby enabling the fabrication of sodium-ion batteries with high energy density and rapid dynamics. Carbon materials are highly valued in the energy-storage field due to their diverse structures, low cost, and high reliability. This review comprehensively summarizes the typical structure; energy-storage mechanisms; and current development status of various carbon-based anode materials for SIBs, such as hard carbon, soft carbon, graphite, graphene, carbon nanotubes (CNTs), and porous carbon materials. This review also provides an overview of the current status and future development of related companies for sodium-ion batteries. Furthermore, it offers a summary and outlook on the challenges and opportunities associated with the design principles and large-scale production of carbon materials with high-energy-density requirements. This review offers an avenue for exploring outstanding improvement strategies for carbon materials, which can provide guidance for future application and research. [ABSTRACT FROM AUTHOR]

Unveiling the dynamic active site of defective carbon-based electrocatalysts for hydrogen peroxide production. [Display omitted] Defective carbon materials have emerged as promising candidates for the electrocatalysis of oxygen reduction reaction (ORR) to selectively produce H 2 O 2. However, distinguishing the roles of oxygenates and carbon defects in carbon for 2e- ORR remains to be challenging. In a recent issue of Nature Communications, Yao and coworkers pinpointed the major active sites in oxygenated carbon materials and identified the key intermediate employing a series of dynamic and simulation techniques. In addition to highlight the proposed work, this comment article also discussed pioneering methodologies to characterize structure dynamics and probe the integral active center for rational design of carbon based catalysts with atomic precision. [ABSTRACT FROM AUTHOR]

The preliminary results of experimental modeling of the impact process on a coal substance by short-pulse laser radiation are presented. During the experiments, extremely high temperatures and pressures were reached. Based on the analysis of the modified products of the target substance, coal melting was identified, followed by its cooling with subsequent solidification with the formation of glass-like carbon. The synthesis products may be of interest as novel carbon materials formed at ultrahigh pressures and temperatures, such as high-pressure carbon polymers and hollow fullerene-like structures. The results of experimental modeling can be used for comparison with naturally occurring materials in order to elucidate the mechanisms of the formation of natural high-pressure carbon substances from a non-graphite precursor. [ABSTRACT FROM AUTHOR]

The porous structure SnFe3N@carbon materials (SnFe3N@C) and the fibrous structure SnFe3N@carbon materials (SnFe3N@CNFs) were synthesized by the simple sintering method and the electrospinning-sintering method using polyacrylonitrile and dicyandiamide as carbon and nitrogen sources. The XRD results demonstrates that the various structures of the SnFe3N@carbon materials are well crystallized, and TG analysis reveals that all samples contain approximately 60 wt% carbon, providing insights into the composition and the percentage of organic matter present. Raman spectroscopy and X-ray photoelectron spectroscopy further verified the XRD results, and no impurity phases were formed in the prepared products. VSM measurements revealed that the prepared two different structural SnFe3N@carbon materials exhibit superparamagnetic properties.

Synthesis of nanofibrous carbon (multi-wall carbon nanotubes, MWCNTs) by means of n-hexane pyrolysis is reported. The structure of the obtained MWCNTs was studied using scanning electron microscopy, and the diameters of 20–85 nm and lengths of 500–600 nm for these nanotubes were observed. By using the above mentioned MWCNTs field-effect transistors were fabricated on ITO glass substrates with a gate dielectric made of 390 nm thick Al2O3 foil and the drain-source contacts made of 300 nm thick aluminum foil. The Nano-C film 200 nm thick was deposited by thermal evaporation in vacuum. The properties of the obtained field-effect transistors were studied. The current-voltage characteristics of the OFET show an increase in currents with a positive voltage on the gate, which corresponds to the electron conductivity of the transport channel. The dependences are nonlinear, and there are no saturation regions in the output characteristics. The Raman spectra indicate the presence of nickel and show characteristic peaks for C=C and CH bonds.

Effective surface functionalization of carbon nanomaterials plays a crucial role in various applications. We investigated the impact of edges on surface functionalization and stability of oxygen-modified carbon materials using a combination of experimental techniques and Density Functional Theory (DFT) insights. Graphenic paper, highly oriented pyrolytic graphite (HOPG), and graphenic flakes were employed as model systems, with oxygen plasma treatment (generator power 100 W, oxygen pressure 0.2 mbar, exposure time 6 – 300 s) serving as the modification method. Surface morphology and chemical composition were characterized using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. The results revealed the introduction of oxygen functional groups on the investigated carbon surfaces (up to 20 at % by XPS) whereas; the structural integrity of the materials remained intact upon plasma modification (SEM, Raman). Work function was used as a sensitive parameter for monitoring the surface changes (increase by ∼1.4 eV, 1.3 eV, and 1 eV for graphenic paper, HOPG, and graphenic flakes, respectively) while time-dependent measurements revealed distinct kinetic processes governing the decay of functionalization, highlighting the role of surface defects in post-plasma processes. DFT calculations provided molecular-level insights into the surface processes, elucidating the mechanisms underlying the diffusion of hydroxyls, their recombination, and water desorption. Since the calculated activation barrier for recombination on basal graphenic planes (∼1.0 eV) and edges (∼5.5 eV) are distinctly different, it can be thus concluded that the persistent functionalization is due to the surface edges. Our findings contribute to a deeper understanding of surface modification processes of carbon materials and offer rationales for the design of advanced functional nanomaterials with tailored surface properties.

Exfoliated graphite (EG) is a promising macroporous sorbent for oils and liquid hydrocarbons on water surfaces. The preparation of EG includes a synthesis of graphite intercalation compounds, expandable graphite and its thermal exfoliation. The structure of the initial graphite intercalation compound (GIC) has a significant influence on the structure of exfoliated graphite and its sorption properties: sorption capacity and selectivity of water/octane sorption. Thus, the aim of this work was to investigate the relationship between the structure of EG based on 1st stage, 2nd stage, 3rd stage, 4th stage GICs and EG sorption properties and water wettability. The influence of the GIC stage number on the EG sorption and surface properties is studied. EG obtained from 1st stage GIC at 1000 °C is characterized by a higher sorption capacity toward octane than EG from 4th stage GIC. The selectivity of octane/water sorption reduces when decreasing the GIC stage number from 4 to 1. The high sorption of water can be explained by a higher surface area of EG and the presence of remaining oxygen groups on the edges of graphite crystallites in the EG structure. The EG structure was investigated by XRD, SEM, nitrogen adsorption–desorption method, FTIR and Raman spectroscopy. [ABSTRACT FROM AUTHOR]

In this study, the characteristics of grout mixed with charcoal as an expansive agent were examined to reduce the pre-hardening shrinkage of cementitious materials. This study compared and reviewed the application of CSA, a conventional expansive agent, to grout. The setting time, fluidity, compressive strength, and pre-hardening shrinkage/expansion were evaluated to explore the usability of charcoal as an expansive agent. The test results confirmed that, as the incorporation rate of charcoal increased, the pre-hardening expansion rate of the grout also increased, making it more effective for pre-hardening expansion than the conventional expansive agent CSA. However, when charcoal was used as an expansive agent, the compressive strength decreased after hardening, indicating the need for caution regarding the amount of charcoal used. Furthermore, the pre-hardening shrinkage and expansion rates of the various types of charcoal used in this study showed some differences, suggesting the need for further research on the internal pore volume and pore size of the charcoal. [ABSTRACT FROM AUTHOR]

In the pursuit of fabricating functional ceramic nanostructures, the design of preceramic functional polymers has garnered significant interest. With their easily adaptable chemical composition, molecular structure, and processing versatility, these polymers hold immense potential in this field. Our study succeeded in focusing on synthesizing ferrocene-containing block copolymers (BCPs) based on polyacrylonitrile (PAN). The synthesis is accomplished via different poly(acrylonitrile-block-methacrylate)s via atom transfer radical polymerization (ATRP) and activators regenerated by electron transfer ATRP (ARGET ATRP) for the PAN macroinitiators. The molecular weights of the BCPs range from 44 to 82 kDa with dispersities between 1.19 and 1.5 as determined by SEC measurements. The volume fraction of the PMMA block ranges from 0.16 to 0.75 as determined by NMR. The post-modification of the BCPs using 3-ferrocenyl propylamine has led to the creation of redox-responsive preceramic polymers. The thermal stabilization of the polymer film has resulted in stabilized morphologies based on the oxidative PAN chemistry. The final pyrolysis of the sacrificial block segment and conversion of the metallopolymer has led to the formation of a porous carbon network with an iron oxide functionalized surface, investigated by scanning electron microscopy (SEM), energy dispersive X-ray mapping (EDX), and powder X-ray diffraction (PXRD). These findings could have significant implications in various applications, demonstrating the practical value of our research in convenient ceramic material design. [ABSTRACT FROM AUTHOR]

This study investigates nitrogen-doped carbon synthesis and electrochemical properties as electrode material for energy storage devices, an additional focus of the work is on the electrochemical exfoliation synthesis of nitrogen-doped carbon using various precursors and doping methods. The physical properties of the synthesized sample are characterized using X-ray photoelectron spectroscopy, scanning electron microscopy, and Raman spectroscopy. The electrochemical properties of the N-doped carbons are studied using cyclic voltammetry and galvanostatic charge-discharge cycling. Finally, the work explores the potential application of the N-doped carbons as electrode material for energy storage devices, such as supercapacitors. The results show that N-doped carbons exhibit electrochemical performance superior to that of graphene oxide, with higher electrical capacitance. The results demonstrate the potential of N-doped carbons as high-performance electrode materials for electrochemical energy storage applications. This paper aims to explain the advantages of N-doping in carbon materials more precisely in graphene and the use of these materials in creating electrodes for application in supercapacitors and batteries. [ABSTRACT FROM AUTHOR]

Five different biomass wastes—orange peel, coffee grounds, cork, almond shell, and peanut shell—were transformed into biochars (BCs) or activated carbons (ACs) to serve as adsorbents and/or ozone catalysts for the removal of recalcitrant water treatment products. Oxalic acid (OXL) was used as a model pollutant due to its known refractory character towards ozone. The obtained materials were characterized by different techniques, namely thermogravimetric analysis, specific surface area measurement by nitrogen adsorption, and elemental analysis. In adsorption experiments, BCs generally outperformed ACs, except for cork-derived materials. Orange peel BC revealed the highest adsorption capacity (Qe = 40 mg g−1), while almond shell BC showed the best cost–benefit ratio at €0.0096 per mg of OXL adsorbed. In terms of catalytic ozonation, only ACs made from cork and coffee grounds presented significant catalytic activity, achieving pollutant removal rates of 72 and 64%, respectively. Among these materials, ACs made from coffee grounds reveal the best cost/benefit ratio with €0.02 per mg of OXL degraded. Despite the cost analysis showing that these materials are not the cheapest options, other aspects rather than the price alone must be considered in the decision-making process for implementation. This study highlights the promising role of biomass wastes as precursors for efficient and eco-friendly water treatment processes, whether as adsorbents following ozone water treatment or as catalysts in the ozonation reaction itself. [ABSTRACT FROM AUTHOR]