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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.

Carbon dots (CDs) have rapidly emerged as a new family of carbon‐based nanomaterials since their initial discovery two decades ago. Numerous appealing properties, such as precursor and synthesis process flexibility, tunable photoluminescence, and good biocompatibility, have enabled their widespread applications in sensing, catalysis, energy, and biomedical fields. As the field expands, notable efforts have recently focused on mechanistically elucidating the structural formation and optical behavior of CDs. However, the absence of "clean" CDs presents a major obstacle to achieving a solid understanding of these aspects. Often, the claimed CDs are, in fact, a mixture of small molecules, oligomers, nano‐sized aggregates, or even microparticles. Such coexistence of impurities markedly impacts the physicochemical properties of resulting CD‐based mixtures, hampering the resolution of key mechanistic questions. Here, we aim to address this fundamental shortcoming of the field, going beyond the customary focus of the existing reviews that predominantly cover synthesis, optical performance, and application prospects. We begin with an overview of CD synthesis and then thoroughly examine the purification methods, including filtration, dialysis, electrophoresis, and chromatography. The insights provided here will guide the researchers towards obtaining high‐quality CDs, employing proper combinations of available tools, and ultimately paving the way for more demanding applications. [ABSTRACT FROM AUTHOR]

Carbon materials are of great significance in state‐of‐the‐art electrochemical CO2 reduction (ECR) as key components such as electrocatalysts, gas diffusion electrodes, and current collectors. Notably, dimensionalities of carbons and related manipulations play vital roles in boosting ECR performance, e.g., mass/charge transfer dynamics, exposure of active sites, reaction space, product's Faradaic efficiency/selectivity, and durability. Here, recent endeavors in dimensionality engineering toward advanced carbon‐based materials for ECR is first summarized, including pure carbons (e.g., carbon nanotube and graphene) and carbon composites, and highlight the dimensionality‐dependent properties toward ECR performance. Various engineering strategies referring to dimensionality modulation and integration have been summarized, e.g., top‐down, bottom‐up, and soft chemical approaches. Design principles of dimensionality‐varied carbons are elaborated, the impacts of dimensionalities of carbons and related surface chemistry (e.g., functional group, wettability, and electronic structure) on ECR kinetics and product‐targeted mechanisms are also scrutinized. Some insights into how the dimensionality manipulation of carbons elevates performance of carbon‐based materials in mass/charge transfer acceleration, ECR kinetics, and product selectivity are provided. At last, a perspective for challenges and future development of dimensionality‐varied carbon materials is discussed. This review aims at providing guidance for customizable construction of carbon materials with dimensionality dependence toward green and energy‐saving electrosynthesis systems. [ABSTRACT FROM AUTHOR]

The controlled synthesis of precise carbon nanostructures with high electron conductivity, high reaction activity, and structural stability plays a significant role in practical applications yet largely unmet. Metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and coordination polymers (CPs) as crystalline porous materials (CPMs) have shown extraordinary porosity, tremendous structural diversity, and highly ordered pores, offering a platform for precise controlled carbon materials (CMs) with regular porous structures and high performances. Some recent studies have shown that CMs derived from CPMs with high specific surface area, superior chemical stability, excellent electrical conductivity offer a great opportunity for electrochemical energy storage and conversion. In this review, we summarize recent milestones of CPMs derived CMs in the field of capacitive energy storage. We hope the more precise design and control at the atomic level of CPMs could provide us a constructive view of the structure-activity relationship between CMs and electrochemical capacitors, as well as future trends and prospects. [ABSTRACT FROM AUTHOR]

The energy density of batteries can be increased by using high-load cathode material matched with sodium (Na) metal anode. However, the large polarization of the battery under such harsh conditions will promote the growth of Na dendrites and side reactions. Carbon materials are regarded as ideal modify layers on Na metal anode to regulate the Na+ plating/stripping behavior and inhibit the Na dendrites and side reactions due to their light weight, high stability and structural adjustability. However, commonly used carbon nanotubes and carbon nanofibers cannot enable these modified Na metal anodes to operate stably in full batteries with a high-load cathode (> 15 mg·cm−2). The most fundamental reason is that abundant polar functional groups on the surface bring serious side reactions and agglomerations lead to uneven Na+ flow. Here, a proof-of-concept study lies on fabrications of carbon nanospheres with small amount of polar functional groups and sodiophobic components on the surface of Na metal anode, which significantly enhances the uniformity of the Na+ plating/stripping. The assembled symmetric battery can cycle stability for 1300 h at 3 mA·cm−2/3 mAh·cm−2. The full battery with high-load Na3V2(PO4)3 (30 mg·cm−2) maintains a Coulombic efficiency of 99.7% after 100 cycles. [ABSTRACT FROM AUTHOR]

Supercapacitors have gathered significant interest in addressing the increasing need for energy storage devices with high power and energy densities. This study introduces a composite framework designed to enhance supercapacitor performance by leveraging the synergistic effects of g-C 3 N 4 /rGO composite. The composite electrode, which combines rGO for high conductivity and g-C 3 N 4 for rapid ion diffusion, demonstrates excellent supercapacitor performance. The synthesized materials were characterized using different analytical tools such as X-ray diffraction, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller, Scanning and Transmission electron microscope, and X-ray photoelectron spectroscopy. The composite electrode exhibited outstanding performance characteristics, including a specific capacitance of 407.7 F/g, an energy density of 11.4 W h/kg, and a high power density of 186.7 W/kg. Kinetic analysis revealed that the g-C 3 N 4 /rGO composite electrode has a dominant diffusive controlled process. The g-C 3 N 4 /rGO electrode also demonstrated exceptional durability, maintaining remarkable capacitance retention even after the 5000th charge/discharge cycles. Moreover, the cyclic s tability and Coulombic efficiency of the g-C 3 N 4 /rGO electrode were modeled and predicted by utilizing the time series analysis technique (Holt-Winters exponential smoothing). Considering the overall results, the g-C 3 N 4 /rGO composite electrode has a great potential for energy storage applications. [Display omitted] • g-C 3 N 4 /rGO composite shows good specific capacitance (407.7 F/g). • Demonstrate good energy density (11.4 W h/kg) and power density (186.7 W/kg). • Composite shows good stability (83%) and retains the 89% Coulombic efficiency. • g-C 3 N 4 /rGO supercapacitor can be stable up to 5000 cycles. • Cyclic data of composite modeled and predicted using time series analysis method. [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]

Heterogeneous structured nanomaterials can be considered as a class of advanced materials that integrate multiple phases, different elements, or components into a single nanoscale structure. For such materials, the different phases, components and their interactions are highly variable and tunable, which open a new avenue for the creation of new materials with unique properties unattainable by the corresponding single‐phase materials. In this review, heterogeneous structured nanomaterials constructed by different carbon allotropes are focused. Due to the unique bonding ability of carbon element, the diverse heterogeneous structures constructed by carbon structures with different dimensions possess distinctive structures and exhibit fascinating properties, providing unprecedented opportunities for various application fields, including electronic/optoelectronic devices, superhard materials, etc. This review provides a systematic elaboration for carbon‐based heterogeneous structured nanomaterials, highlighting their dimension‐dependent structural diversity, unique properties, and application prospects. [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]

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]

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]

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]

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]

Fabrication of highly efficient and earth-abundant bifunctional electrocatalyst to accelerate the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are critical for overall water splitting. In this work, bimetallic Co/Mo oxides modified reduced graphene oxide (rGO) was synthesized using a simple one-pot hydrothermal method, which significantly improved the electrocatalytic activity in both HER and OER. Under the optimal conditions, the double layer capacitance of rGO modified by Co/Mo bimetal is 78.08 mF cm−2. The overpotential required for HER to reach -10 mA cm−2 current density is 488 mV, the dynamic Tafel slope is 126 mV dec−1. The overpotential required for OER to reach 10 mA cm−2 current density is 420 mV, the slope of kinetic Tafel is 169 mV dec−1. This work provides a new prospect for the rational design and fabrication of efficient HER/OER bifunctional electrocatalysts in electrochemical energy device application. [ABSTRACT FROM AUTHOR]

Copyright of Low-Carbon Chemistry & Chemical Engineering is the property of Low-Carbon Chemistry & Chemical Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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]

Facilitating the transition and new application of fossil energy sources are crucial to attaining carbon neutrality. Conversion of coals into graphitic carbons represents an effective route to achieve their high‐value utilization, while this process always involves corrosive/toxic chemical reagents and time‐intensive heating treatment. Here, this work reports a green, rapid, and efficient flash Joule heating (FJH) technique to produce high‐quality carbons from diverse coals within 1 s. The surface groups, defects, and graphitization degree of the resultant carbon materials are controlled during the instantaneous thermal shock process, and the relationships between the coal structures and the product properties are established. The results suggest that the anthracite with high coalification degree tends to form highly graphitic carbons at a peak temperature of ≈3300 K, presenting higher rate capability (79.1% capacity retention at 30 A g–1) and low relaxation time constant (τ0 = 0.27 s) toward capacitive energy storage. Besides, the flash carbon materials derived from lignite and bituminous coal with low coal rank show better capacitive performance with capacity above 80 F g–1 at 1 A g–1. This study evidences that the FJH technology holds great potential to steer coals into valuable carbon materials. [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]

Supported metal single atom catalysis is a dynamic research area in catalysis science combining the advantages of homogeneous and heterogeneous catalysis. Understanding the interactions between metal single atoms and the support constitutes a challenge facing the development of such catalysts, since these interactions are essential in optimizing the catalytic performance. For conventional carbon supports, two types of surfaces can contribute to single atom stabilization: the basal planes and the prismatic surface; both of which can be decorated by defects and surface oxygen groups. To date, most studies on carbon‐supported single atom catalysts focused on nitrogen‐doped carbons, which, unlike classic carbon materials, have a fairly well‐defined chemical environment. Herein we report the synthesis, characterization and modeling of rhodium single atom catalysts supported on carbon materials presenting distinct concentrations of surface oxygen groups and basal/prismatic surface area. The influence of these parameters on the speciation of the Rh species, their coordination and ultimately on their catalytic performance in hydrogenation and hydroformylation reactions is analyzed. The results obtained show that catalysis itself is an interesting tool for the fine characterization of these materials, for which the detection of small quantities of metal clusters remains a challenge, even when combining several cutting‐edge analytical methods. [ABSTRACT FROM AUTHOR]

Mechanochemical reactions by ball milling have opened new avenues in chemical synthesis. Particularly, mechanochemistry has facilitated the reaction of insoluble materials to simplify stablished synthetic protocols and develop new ones. One notable application involves the use of calcium carbide (CaC2) as a C2‐synthon through mechanochemistry, which has offered a more practical alternative to incorporate C2‐units compared to the conventional use of highly flammable gaseous acetylene. For example, by ball milling, the acetylenic anions [C2]2− found in CaC2 have been harnessed for the synthesis of diverse functional carbon materials as well as discrete organic molecules. This Concept aims to contribute to the conceptualization of this innovative approach while highlighting both its advantages and the challenges inherent in the use of CaC2. [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]

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]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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.

The escalating severity of plastic waste's impact on the ecological environment and human health emphasize the crucial importance of developing resource‐conserving disposal technologies for sustainable development. Carbon‐based materials possess extensive functional applications across various fields, however, their high production costs and heavy reliance on fossil fuels pose challenges. Plastic wastes serve as ideal precursors for the green and sustainable production of carbon‐based functional materials due to high carbon content and low‐cost. This review provides a comprehensive summary of recent research progress on plastic waste‐derived carbon materials (PWCMs) including primary strategies for constructing PWCMs and their current functional applications in energy storage, environmental remediation and organic synthesis. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) materials are widely studied, and yet their atomic‐scale structures remain to be fully understood. Here we show that the chemical and configurational space of GO can be rapidly explored by advanced machine‐learning methods, combining on‐the‐fly acceleration for first‐principles molecular dynamics with message‐passing neural‐network potentials. The first step allows for the rapid sampling of chemical structures with very little prior knowledge required; the second step affords state‐of‐the‐art accuracy and predictive power. We apply the method to the thermal reduction of GO, which we describe in a realistic (ten‐nanometre scale) structural model. Our simulations are consistent with recent experimental findings, including X‐ray photoelectron spectroscopy (XPS), and help to rationalise them in atomistic and mechanistic detail. More generally, our work provides a platform for routine, accurate, and predictive simulations of diverse carbonaceous materials. [ABSTRACT FROM AUTHOR]

This work reports on the determination of the heat conductivity of high temperature stable carbon materials in the temperature range well above 2000 °C where classic material characterization methods fail. Dense graphite (DG) materials as well as rigid and soft felt isolation (RFI/SFI) components have been investigated which are used during crystal growth of SiC by the physical vapor transport method (PVT) in the temperature regime of 2000 and 2400 °C. The applied materials characterization methods include low temperature physical heat conductivity measurements using laser flash analysis (LFA) in the temperature range 25–1200 °C, data extrapolation to elevated temperatures up to 2400 °C, and a correlation of heating processes and computer simulation of the temperature field of different hot zone designs. Using this approach, the calculated temperatures and experimentally determined values with an error of less than ± 2% at 2400 °C can be merged. [ABSTRACT FROM AUTHOR]

The demand for diesel has been decreasing year on year in recent years, LCO (light cycle oil of FCC unit), as the main component of diesel pools, has encountered the problem of overcapacity. The key to solving the overcapacity of LCO is to make reasonable use of the rich bicyclic aromatic hydrocarbon components in LCO and explore new technologies for the conversion of suitable aromatics to aromatics. Starting from the structural composition of LCO, this paper systematically summarizes the recent development status of six technologies for producing various high-value products using LCO as raw material. Among them, LTAG technology has a high yield of high octane gasoline, but reducing reaction hydrogen consumption is a major challenge; LCO preparation of BTX is an effective method for oil conversion, but high hydrogen consumption low selectivity of BTX lead to poor tech no-economics; the preparation of COP- NA resin by LCO can produce high-performance B resin with by-production of high cetane diesel components. However, the curing and crosslinking agents used still have the problem of being expensive. Finally, summary and outlook were made on the current technical issues of LCO production of high-value products. [ABSTRACT FROM AUTHOR]

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]

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]

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]

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Ammonium perchlorate (AP), as an oxidant and a main component in solid propulsion, has been of wide concern by researchers in recent years. However, problems, such as higher high-temperature decomposition peaks and nonconcentration of exothermic heat release, hinder its application. The addition of combustion catalysts can resolve these problems, but the small size of metals is prone to agglomeration and affects the performance of AP. Graphene oxide, which has a large specific surface area as a carrier, hydroxyethyl cellulose as an intercalating agent, cobalt nitrate as the three-dimensional porous carbon aerogel were prepared as catalyst for AP. The high-temperature decomposition peak of AP was greatly reduced by 116.5 K, which resulted in a great energy release. [ABSTRACT FROM AUTHOR]

This paper firstly describes the basic principle of low-temperature plasma technology. Secondly, the applications of plasma in surface modified carbon nanotubes, graphite, graphene oxide and new porous carbon materials are introduced respectively. And some research results in this field at home and abroad are listed. Some shortcomings of surface modification by low-temperature plasma are discussed and its future development is prospected. [ABSTRACT FROM AUTHOR]

Traditionally, combining carbon and ceramic materials has been challenging due to their different chemical and physical properties. Despite the development of numerous methodologies for their synthesis, these techniques frequently necessitate intricate, multi‐stage protocols and specialized equipment. This study introduces a novel approach for fabricating nanostructured carbon‐ceramic multimaterials through polymerization‐induced microphase separation 3D printing. By combining inorganic precursors, polycarbosilane, and acrylonitrile (AN) within a photocurable resin, heterogeneous nanostructured materials composed of PAN‐preceramic and sacrificial polymer phases are 3D printed. Upon pyrolysis, PAN‐preceramic domains transformed into a carbon‐ceramic matrix while sacrificial polymer domains thermally decomposed to yield nanoscale voids. The utilization of synchrotron X‐ray spectroscopy and microscopy techniques revealed that the phase compositions and microstructure of the resulting multi‐materials are significantly influenced by the initial composition of the resins. The co‐existence of ceramic and carbon phases within a single 3D printed material brought together a combination of properties from both phases, such as the low thermal conductivity of ceramics and the relatively high electrical conductivity of carbon, along with the exceptional chemical resistance. The insights into the microstructure, atomic configuration, and property relationships of the resulting materials have broad implications for the development of multi‐phase nanostructured hybrid materials. [ABSTRACT FROM AUTHOR]

A number of new micro-mesoporous carbon materials (FHU100N, FHU100K, FHU70N30K, FHU50N50K and FHU20N80K) based on a mixture of furfural, hydroquinone, and urotropine have been synthesized by the alkaline activation method using a combination of activating agents (KOH and NaOH). The influence of the porous structure of the synthesized adsorbents has been studied with particular attention to the pore size distribution, in particular, to the pore volume in which MG can be adsorbed most efficiently from aqueous solutions. Subsequently, among the tested carbons, the FHU100N has excellent porosity (total pore volume, micropore volume and mesopore volume: 1.136, 0.632 and 0.504 cm3 /g, respectively) with the highest surface area (2575 m2 /g). The adsorption capacity of FHU100N (1300 mg/g) for malachite green (MG) was superior to other micro mesoporous carbons (500–918 mg/g). The results obtained showed that the key contribution to the adsorption of the MG dye is made by pores ranging in size from 2 to 3.5 nm. The FHU100N adsorbent, which showed the highest MG adsorption activity, was characterized by nitrogen adsorption, FTIR, Raman spectroscopy, and XRD techniques. To understand the adsorption mechanisms on the obtained material, detailed mathematical analysis of experimental sorption data was carried out using the existing kinetic (pseudo-first order and pseudo-second order) models and diffusion (Weber-Morris and Boyd) models, along with adsorption equilibrium isotherms (Langmuir, Freundlich, Temkin, Dubinin-Radushkevich). [ABSTRACT FROM AUTHOR]

One of the many possible ways to capture carbon dioxide (CO2) is through electrochemical means. This is an emerging approach with various merits. It is energy efficient, utilizes renewable energy, operates under ambient conditions, provides ease for control of reaction rates, and is scalable. Additionally, it can be integrated as a plug‐and‐play module at various scales, including large industrial sources or at small scale, e.g., on vehicles, and can easily combine CO2 capture, storage, and utilization into value‐added chemicals. Various "proof‐of‐concept" electrochemical CO2 capture approaches have been demonstrated in the recent past. These are made possible with electro‐active materials that capture, separate, and concentrate CO2 in the form of electrodes, electrolytes, and membranes in devices. Herein, these materials and their working mechanisms are identified and reviewed in various electrochemical CO2 capture devices where they are utilized. Also, the current challenges and future research directions with the identified electrodes, electrolytes, and membranes are summarized to give a rational understanding and guidance for selecting and designing materials for use in electrochemical CO2 capture devices. [ABSTRACT FROM AUTHOR]

A core–shell Co@C composite catalyst was prepared, characterized and used to activate peroxymonosulfate (PMS) for the degradation of paracetamol in water. Hybridized structures containing Co and graphitized carbon act as independent active sites for PMS activation initiating both radical and nonradical oxidation. A 91.57% paracetamol removal was reached in the Co@C/PMS system at 60 min. Radical quenching and electron paramagnetic resonance (EPR) tests show that nonradical 1O2 played predominant roles in the advanced oxidation process, while the other three radicals ⋅O2−, •OH and SO4•. also played a certain role in paracetamol degradation. After four cycles, the degradation could still reach 70%, which proves that the Co@C composite catalyst exhibits good stability. [ABSTRACT FROM AUTHOR]

A method is presented to quantitatively analyze the reduction of vanadium(V) to vanadium(IV) over two flat carbon substrates (glassy carbon and graphite foil) using the feedback mode of scanning electrochemical microscopy. A pulse profile is validated and applied during approach curve experiments of a 10 μm Pt microelectrode. By fitting the approach curve data, electron transfer constants are calculated for various potentials and k0 is extracted from the corresponding Tafel plot. Furthermore, surface functional groups were introduced to the carbon substrates by acid treatment; however, kinetic parameters of the sluggish reduction reaction were only influenced to a minor extent. Finally, the same approach, combined with in situ‐Raman microscopy, is applied to a single graphene layer using a 2.7 μm Pt microelectrode. In this case, increased activity for both, the vanadium(V) reduction and vanadium(IV) oxidation reaction, was found close to the graphene edge sites by means of electrochemical microscopy for the first time. [ABSTRACT FROM AUTHOR]

Graphene has attracted much interest in many scientific fields because of its high specific surface area, Young's modulus, fracture strength, carrier mobility and thermal conductivity. In particular, the graphene oxide (GO) prepared by chemical exfoliation of graphite has achieved low-cost and large-scale production and is one of the most promising for Cu matrix composites. Here, we prepared a high strength, high electrical conductivity and high thermal conductivity reduced graphene oxide (RGO)/Cu composite by directly heating the GO/copper formate. The oxygen-containing functional groups and defects of RGO are significantly reduced compared with those of GO. The tensile yield strength and thermal conductivity of RGO/Cu composite with RGO volume fraction of 0.49 vol.% are as high as 553 MPa and 364 W/(m·K) at room temperature, respectively. The theoretical value of the tensile yield strength of the composite is calculated according to the strengthening mechanism, and the result shows that it agrees with the experimental value. After hot-rolling treatment, the ductility and conductivity of the composite materials have been greatly improved, and the ductility of the RGO/Cu composite with RGO volume fraction of 0.49 vol.% has been increased to four times the original. This work provides a highly efficient way to fabricate a high-performance RGO-reinforced Cu composite for commercial application. [ABSTRACT FROM AUTHOR]

Graphene has become a prominent material in cancer research in recent years. Graphene and its derivatives also attract attention as carriers in drug delivery systems. In this study, we designed a graphene oxide (GO)-based methotrexate (MTX)-loaded and folic acid (FA)-linked drug delivery system. MTX and FA were bound to GO synthesized from graphite. MTX/FA/GO drug delivery system and system components were characterized using Fourier transform infrared spectroscopy (FTIR), differential calorimetric analysis (DSC), scanning electron microscopy (SEM), transmission electron microscopy (TEM), zeta potential analysis, and dimension measurement (DLS) studies. SEM and TEM images confirmed the nanosheet structure of GO synthesized from graphite, and it was shown that MTX/FA binding to GO transformed the two-dimensional GO into a three-dimensional structure. FTIR and DSC graphs confirmed that oxygen atoms were bound to GO with the formation of carboxylic, hydroxyl, epoxide, and carbonyl groups as a result of the oxidation of graphite, and GO was successfully synthesized. Additionally, these analyses showed that MTX and FA bind physicochemically to the structure of GO. The in vitro Franz diffusion test was performed as a release kinetic test. The release kinetics mathematical model and correlation coefficient (R2) of MTX-loaded GO/FA nanomaterials were found to be the Higuchi model and 0.9785, respectively. Stiffness analyses showed that adding FA to this release system facilitated the entry of the drug into the cell by directing the system to target cells. As a result of the stiffness analyses, the stiffness values of the control cell group, free MTX, and MTX/FA/GO applied cells were measured as 2.34 kPa, 1.87 kPa, and 1.56 kPa, respectively. According to these results, it was seen that MTX/FA/GO weakened the cancer cells. Combined use of the MTX/FA/GO drug delivery system had a higher cytotoxic effect than free MTX on the MDA-MB-231 breast cancer cell line. The results showed that the synthesized MTX/FA/GO material has promising potential in cancer cell-specific targeted therapy for MTX as a drug delivery system. [ABSTRACT FROM AUTHOR]

Materials science and catalysis advancements play a critical role in achieving sustainable development by managing environmental, energy, and resource challenges. Catalyst design advancements focus on enhancing selectivity to achieve sustainable chemical reactions, reducing energy consumption. Designing catalysts that are environmentally friendly and biodegradable is increasingly gaining importance. This aligns with the principles of green chemistry and contributes to minimizing the environmental impact of catalytic processes. These advances, taken as a whole, lead to more sustainable and efficient processes in industries ranging from energy production to pollutant removal, fueling the advancement toward a more sustainable future. Photochemistry, that is, the activation of a stable compound (catalyst) into the highly reactive excited state, is of particular importance, since photons—especially when they come from solar light—are a green and renewable resource. This review article has provided the overall idea of the photocatalysts and materials under green chemistry perspective from the standpoint of the concept of sustainable development. [ABSTRACT FROM AUTHOR]

Effective charge separation and use of hot charge carriers are considered to be the most essential factors affecting the activity of an excellent energy harvester. Herein, we have successfully decorated 3 nm of CdSe quantum dots (QDs) on the surface of reduced graphene oxide (rGO) using solvothermal method. Formation of CdSe–rGO nanocomposite (NC) has been confirmed by X-ray diffraction pattern, transmission electron microscopy and Raman analysis. Further, the emission spectrum of CdSe–rGO NC shows quenching of emission of CdSe QDs on the surface of rGO nanosheet. To elucidate this phenomenon, we have carried out time-correlated single-photon counting (TCSPC) measurements, which reveal efficient electron transfer, as the exciton lifetime of CdSe QDs in the NC is significantly reduced compared to bare CdSe QDs. Owing to the efficient electron transfer, this NC showed big boost in total shielding effectiveness (SET = 29 dB) when compared to graphene (SET = 23 dB) in electromagnetic interference shielding application. [ABSTRACT FROM AUTHOR]

Lignin is a promising precursor to produce graphene materials due to its high carbon and aromatic contents. Upgrading lignin into graphene materials has gained significant interests as it offers a cost‐effective and sustainable route to produce high‐performance carbon materials. This review provides a comprehensive overview of the state‐of‐the‐art technologies on lignin to graphene materials with a focus on thermal catalytic and photothermal upgrading. The applications of lignin‐derived graphene materials and the perspectives for mass production of such graphene materials are also discussed. [ABSTRACT FROM AUTHOR]

As the core component of supercapacitors (SCs), the electrode material plays a decisive role in performance. Among electrode materials, carbon materials are the most widely used due to high porosity and specific surface area (SSA, 1000–3000 m2 g−1). Biomass carbon stands out in carbon materials because of its wide source, low cost, and less pollution. This work reviews the recent advances on carbon materials derived from biomass waste for SCs and explores the effects of different biomass sources including plant, animal, and aquatic organism waste on the performance of biomass waste‐derived carbon materials (BWDCs). Because of its high conductivity (1.25 × 103 ≈ 3 × 105 S m−1), power density (>10 kW kg−1), and extended cycle life (>10 000 cycles), BWDCs are advancing quickly in energy storage. It also discusses different methods and optimization pathways of BWDCs thoroughly. Finally, the challenges and future prospects for BWDCs are summarized. Overall, this critical will help researchers to gain a better understanding of source selection, structural classification, and research strategies for BWDCs, thereby promoting the application of BWDCs in electrochemistry and resource utilization. [ABSTRACT FROM AUTHOR]

To accelerate the implementation of zero-emission power installations based on proton-exchange membrane fuel cells, it is necessary to maximize the power characteristics of these devices. For this purpose, we have obtained and tested a new N-doped carbon support and a synthesized Pt/C catalyst based on it with a platinum loading of about 37.3 %. A comparison of the degradation resistance of the initial support and the N-doped one has shown greater stability of the latter. At the same time, Raman spectroscopy has confirmed the presence of the C–N bond, which indicates the successful doping of carbon with nitrogen. The resulting Pt/C catalyst based on an N-doped support is characterized by a substantially narrow size dispersion and an ultra-small nanoparticle size of about 2.6 nm. The high-angle annular dark-field scanning transmission electron microscopy images of the synthesized catalyst have confirmed the presence of individual platinum atoms/clusters uniformly distributed over the surface of the support, and their presence is due to nitrogen embedded into the carbon structure. This material is characterized by a 50 m2 gPt-1 larger electrochemically active surface area and a 227 A gPt-1 greater mass activity compared to the commercial JM40 analog (40 % platinum loading). Meanwhile, the electrochemical parameters remaining after the accelerated stress testing are almost 2 times higher than those of JM40. And the power characteristics in the membrane electrode assembly for the catalyst synthesized by the facile one-pot synthesis method are 13 % (575 mW cm-2) higher than those of the commercial analog (500 mW cm-2). The Pt/C catalyst obtained during the research is deemed promising for commercial use in proton-exchange membrane fuel cells.