Investigation of nanocrystalline structure in selected carbonaceous materials

The structural parameters of nine Indian coals were determined by X-ray diffraction （XRD） and Kaman spectroscopy. The study revealed that the coals contain crystalline carbon of turbostratic structure with amorphous carbon. The stacking height （Lc） and interlayer spacing （rico2） of the crystallite structure of the coals ranged from 1.986 to 2.373 nm and from 0.334 to 0.340 nm, respectively. The degree of graphitization was calculated to range from 42% to 99%, thereby confirming the ordering of the carbon layers with the increase in coal rank. An exponential correlation was observed among the aromaticity （fa）, the lateral size （La）, and the rank （I20/I26）, suggesting that the coal crystallites are nanocrystalline in nature. A very strong correlation was observed between the structural parameters （fa, d002, Lc, the H/C ratio, and I20/I26）, the volatile matter content, and the elemental carbon content, indicating the structures of coals are controlled by the degree of contact metamorphism. The Raman spectra exhibited two prominent bands： the graphitic band （G） and the fn＇st-order characteristic defect band （D）. The deconvolufion resulted in five peaks： G, D1, D2, D3, and D4. The intense D1 band, which appeared at -1350 cm^-1, corresponds to a lattice vibration mode with Alg symmetry. The D2 mode, which appeared at -1610 cm^-1, arises from the structural disorder as a shoulder on the G band.

A review on novel activation strategy on carbonaceous materials with special morphology/texture for electrochemical storage

Various novel carbonaceous materials including carbon nanotubes,nano-onions,carbon microspheres,graphene nanosheets,and carbon microfibers with unique properties,such as tunable surface area and pore size,high chemical stability,cost-effective and facile preparation,have attracted enormous interest for many applications.Also essential,the activation processes play a critical role to achieve these valuable properties.In this review,we provide a thorough analysis of the emerging nano-and microscopic carbon species with special morphology/textures and currently available types of chemical activation agents,and novel activation strategy to enhance electrochemical performance of activated carbon material in electrical energy storage devices including supercapacitor and alkaline ions batteries.A particular emphasis is set on recent advance in activated carbon materials with special morphology/textures for supercapacitors and sodium ion batteries.

Review on Heteroatom Doping Carbonaceous Materials Toward Electrocatalytic Carbon Dioxide Reduction

Carbon dioxide(CO_(2))reduction into chemicals or fuels by electrocatalysis can eff ectively reduce greenhouse gas emissions and alleviate the energy crisis.Currently,CO_(2)electrocatalytic reduction(CO_(2)RR)has been considered as an ideal way to achieve“carbon neutrality.”In CO_(2)RR,the characteristics and properties of catalysts directly determine the reaction activity and selectivity of the catalytic process.Much attention has been paid to carbon-based catalysts because of their diversity,low cost,high availability,and high throughput.However,electrically neutral carbon atoms have no catalytic activity.Incorpo-rating heteroatoms has become an eff ective strategy to control the catalytic activity of carbon-based materials.The doped carbon-based catalysts reported at present show excellent catalytic performance and application potential in CO_(2)RR.Based on the type and quantity of heteroatoms doped into carbon-based catalysts,this review summarizes the performances and catalytic mechanisms of carbon-based materials doped with a single atom(including metal and without metal)and multi atoms(including metal and without metal)in CO_(2)RR and reveals prospects for developing CO_(2)electroreduction in the future.

Emergence of carbonaceous material for hydrogen storage:an overview

Hydrogen has gained enormous relevance due to its lower carbon footprint and its potential role in balancing energy supply and demand.It is being considered as a sustainable substitute for conventional fuels.The generation of hydrogen using renewable energy sources is still in development,with a significant challenge lying in the efficient and safe storage of hydrogen due to its low energy density.This challenge hinders the widespread adoption of hydrogen.Compression and liquefaction methods of storage face issues of losses that reduce their effectiveness.The technology for hydrogen storage has advanced significantly in the past few years,driven by recent enhancements in synthesizing carbonaceous materials with hydrogen storage capabilities.This article critically reviews novel carbonaceous materials for hydrogen storage,including biochar,activated carbon,carbon nanotubes,carbon nanocomposites,carbon aerogel,fullerenes,MXenes,graphite,graphene and its derivatives.Effective hydrogen adsorption using microporous materials,such as activated carbons,is crucial,sparking interest in economically viable options for hydrogen storage.Despite this,a significant amount of work still needs to be accomplished before the potential and advantages of the hydrogen economy can be fully realized and utilized by manufacturers and academics.

Synthesis of ordered mesoporous carbonaceous materials and their highly efficient capture of uranium from solutions

An extremely effortless method was applied for successful synthesis of mesoporous carbonaceous materials(MCMs) using well-ordered mesoporous silica as template. Various characterizations(scanning electron microscopy(SEM), transmission electron microscopy(TEM), X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FT-IR), Raman, X-ray photoelectron spectroscopy(XPS), Brunner-Emmet-Teller(BET) and Zeta potential) confirmed that MCMs had large surface area, uniform pore size distribution, and abundant oxygen-containing functional groups. The batch techniques were employed to study U(VI) adsorption on MCMs under a wide range of experiment conditions. The adsorption kinetics of U(VI) onto MCMs were well-fitted by pseudo-second-order kinetic model, indicating a chemisorption process. The excellent adsorption capacity of MCMs calculated from the Langmuir model was 293.95 mg g^(-1) at pH 4.0. The FT-IR and XPS analyses further evidenced that the binding of U(VI) onto MCMs was ascribed to the plentiful adsorption sites(–OH and –COOH groups) in the internal mesoporous structure, which could efficiently trap guest U(VI) ions. The results presented herein revealed that MCMs were ideal adsorbents in the efficient elimination of uranium or other lanthanides/actinides from aqueous solutions, which would play an important role in environmental pollution management application.

Improving the Initial Coulombic Efficiency of Carbonaceous Materials for Li/Na‑Ion Batteries:Origins,Solutions,and Perspectives

Carbonaceous materials for lithium(Li)/sodium(Na)-ion batteries have attracted significant attention because of their widespread availability,renewable nature,and low cost.During the past decades,although great efforts have been devoted to developing high-performance carbonaceous materials with high capacity,long life span,and excellent rate capability,the low initial Coulombic efficiency(ICE)of high-capacity carbonaceous materials seriously limits their practical applications.Various methods have been successfully exploited,and a revolutionary impact has been achieved through the utilization of different techniques.Different carbonaceous materials possess different ion storage mechanisms,which means that the initial capacity loss may vary.However,there has rarely been a special review about the origins of and progress in the ICE for carbonaceous materials from the angle of the crystal structure.Hence,in this review,the structural differences between and ion storage mechanisms of various carbonaceous materials are first introduced.Then,we deduce the correlative factors of low ICE and thereafter summarize the proposed strategies to address these issues.Finally,some challenges,perspectives,and future directions on the ICE of carbonaceous materials are given.This review will provide deep insights into the challenges of improving the ICE of carbonaceous anodes for high-energy Li/Na-ion batteries,which will greatly contribute to their commercialization process.

Insoluble carbonaceous materials as electron shuttles enhance the anaerobic/anoxic bioremediation of redox pollutants:Recent advances

Carbonaceous materials can accelerate extracellular electron transfer for the biotransformation of many recalcitrant,redox-sensitive contaminants and have received considerable attention in fields related to anaerobic bioremediation.As important electron shuttles(ESs),carbonaceous materials effectively participate in redox biotransformation processes,especially microbially-driven Fe reduction or oxidation coupled with pollutions transformation and anaerobic fermentation for energy and by-product recovery.The related bioprocesses are reviewed here to show that carbonaceous ESs can facilitate electron transfer between microbes and extracellular substrates.The classification and characteristics of carbon-containing ESs are summarized,with an emphasis on activated carbon,graphene,carbon nanotubes and carbonbased immobilized mediators.The influencing factors,including carbon material properties(redox potential,electron transfer capability and solubility)and environmental factors(temperature,p H,substrate concentration and microbial species),on pollution catalytic efficiency are discussed.Furthermore,we briefly describe the prospects of carbonaceous ESs in the field of microbial-driven environmental remediation.

Roles and mechanisms of carbonaceous materials in advanced oxidation coupling processes for degradation organic pollutants in wastewater:a review

The widespread organic pollutants in wastewater are one of the global environmental problems.Advanced oxidation processes(AOPs)are widely used because of their characteristics of high efficiency and strong oxidation.However,AOPs may have some defects,such as incomplete mineralization of organic pollutants and the generation of toxic by-products during the degradation process,thus it is essential to seek efficient and green wastewater treatment technologies.Coupling different AOPs or other processes is beneficial for the mineralization of pollutants and reduces ecological risks to the environment.It is worth noting that carbonaceous materials(CMs)have received widespread attention and application in the degradation of organic pollutants in water by advanced oxidation coupling processes(C-AOPs)due to their excellent physicochemical properties in recent years.However,the behaviors and mechanisms of C-AOPs based on CMs on the degradation of organic pollutants are still unknown.Therefore,it is essential to comprehensively summarize the recent research progress.In this review,the applications of different CMs in C-AOPs were reviewed first.Secondly,the synergistic mechanisms of the C-AOPs based on different CMs were discussed.Then,toxic intermediates were explored and important toxicity assessment methods were proposed.Finally,the application potential of the C-AOPs in the future and the challenges were proposed.This review provides an important reference for the application and optimization of the C-AOPs in organic wastewater treatment in the future.

A Review of Anode Materials for Dual‑Ion Batteries

Distinct from"rockingchair"lithium-ion batteries(LIBs),the unique anionic intercalation chemistry on the cathode side of dual-ion batteries(DIBs)endows them with intrinsic advantages of low cost,high voltage,and ecofriendly,which is attracting widespread attention,and is expected to achieve the next generation of large-scale energy storage applications.Although the electrochemical reactions on the anode side of DIBs are similar to that of LIBs,in fact,to match the rapid insertion kinetics of anions on the cathode side and consider the compatibility with electrolyte system which also serves as an active material,the anode materials play a very important role,and there is an urgent demand for rational structural design and performance optimization.A review and summarization of previous studies will facilitate the exploration and optimization of DIBs in the future.Here,we summarize the development process and working mechanism of DIBs and exhaustively categorize the latest research of DIBs anode materials and their applications in different battery systems.Moreover,the structural design,reaction mechanism and electrochemical performance of anode materials are briefly discussed.Finally,the fundamental challenges,potential strategies and perspectives are also put forward.It is hoped that this review could shed some light for researchers to explore more superior anode materials and advanced systems to further promote the development of DIBs.

Development of covalent-organic frameworks derived hierarchical porous hollow carbon spheres based LiOH composites for thermochemical heat storage

Under the joint assistance of its excellent storage strength, accessible long storage lifespan, and high heat utilization efficiency, salt hydrate-based thermochemical heat storage(THS) materials give renewable energy an important outlet to alleviate the pressure of underutilization. Herein, an activated hollow spherical carbon(AHSC) with hierarchical porous architectures converted from covalent-organic frameworks(COFs) is constructed and utilized as the supporting matrix for Li OH.THS composite material for the first time. The obtained Li/AHSC_(3) composites have distinguished hydration performance while manifesting impressive storage ability up to 1916.4 k J kg^(-1)with low operating temperature stemming from the collective effect of the void spherical framework, multimodal porosity, and high surface area of AHSC3. And the Li/AHSC3-40 composite with evidently progressed thermal conductivity is capable of realizing 94.5% heat preservation after twenty-five adsorption-desorption cycles, exhibiting its eminent cyclability and great heat transfer performance. This study not only brings new hope for overcoming the underutilization of low-grade heat but also may enlighten new ideas for enriching the application scenarios of COFs-derived carbonaceous materials.

Self-doping active sites in microbe-derived carbonaceous electrocatalysts for the oxygen reduction reaction performance

Microorganisms are rich in heteroatoms,which can be self-doped to form active sites during pyrolysis and loaded on microbederived carbonaceous materials.In recent years,microbe-derived carbonaceous materials,characterized with abundant selfdoping sites,have been continuously developed as cost-effective electrocatalysts for oxygen reduction reaction(ORR).To fully unlock the catalytic potential of microbe-derived carbonaceous materials,a comprehensive analysis of catalytic sites and mechanisms for ORR is essential.This paper provides a summary of the ORR catalytic performance of microbe-derived carbonaceous materials reported to date,with a specific focus on the self-doping sites introduced during their pyrolytic fabrication.It highlights the mono-or co-doping sites involving nonmetallic elements such as oxygen(O),nitrogen(N),phosphorus(P),and sulfur(S)atoms,as well as covers the doping of metallic iron(Fe)atoms with various coordination configurations in microbe-derived carbonaceous materials.Understanding the impact of these self-doping sites on ORR catalytic performance can guide the design of doping sites in microbe-derived carbonaceous materials.This approach has the potential to maximize electrocatalytic activity of microbe-derived carbonaceous materials and contributes to the development of more efficient and cost-effective carbonaceous electrocatalysts.

STUDY ON PREPARATION OF REACTION BURNING SILICON CARBIDE BY CARBON POWDER

The technology of preparing reaction burning silicon carbide (RBSC) by replacing SiC/C with entirely carbonaceous raw materials is investigated. Experimental results show the predominant factors of successfully preparing RBSC are as following:strictly controlling the porosity and pore diameter of biscuit, obtaining ideal carbon network permeating of Si and completely reaction between Si and beta-SiC.

Printable inorganic nanomaterials for flexible transparent electrodes:from synthesis to application

Printed and flexible electronics are definitely promising cutting-edge electronic technologies of the future. They offer a wide-variety of applications such as flexible circuits, flexible displays, flexible solar cells, skinlike pressure sensors, and radio frequency identification tags in our daily life. As the most-fundamental component of electronics, electrodes are made of conductive materials that play a key role in flexible and printed electronic devices. In this review, various inorganic conductive materials and strategies for obtaining highly conductive and uniform electrodes are demonstrated. Applications of printed electrodes fabricated via these strategies are also described. Nevertheless, there are a number of challenges yet to overcome to optimize the processing and performance of printed electrodes.

Functionalization Strategies of Iron Sulfi des for High-Performance Supercapacitors

Supercapacitors have emerged as a promising class of energy storage technologies,renowned for their impressive specifi c capacities and reliable cycling performance.These attributes are increasingly signifi cant amid the growing environmental challenges stemming from rapid global economic growth and increased fossil fuel consumption.The electrochemical performance of supercapacitors largely depends on the properties of the electrode materials used.Among these,iron-based sulfi de(IBS)materials have attracted signifi cant attention for use as anode materials owing to their high specifi c capacity,eco-friendliness,and cost-eff ectiveness.Despite these advantages,IBS electrode materials often face challenges such as poor electrical conductivity,compromised chemical stability,and large volume changes during charge–discharge cycles.This review article comprehensively examines recent research eff orts aiming at improving the performance of IBS materials,focusing on three main approaches:nanostructure design(including 0D nanoparticles,1D nanowires,2D nanosheets,and 3D structures),composite development(including carbonaceous materials,metal compounds,and polymers),and material defect engineering(through doping and vacancy introduction).The article sheds light on novel concepts and methodologies designed to address the inherent limitations of IBS electrode materials in supercapacitors.These conceptual frameworks and strategic interventions are expected to be applied to other nanomaterials,driving advancements in electrochemical energy conversion.

Fabrication of complex,3D,branched hollow carbonaceous structures and their applications for supercapacitors

A unique“integrated hard-templating strategy”is described for facile synthesis of a carbonaceous material with a novel three-dimensional(3 D)branched hollow architecture.A set of steps,including template formation,surface coating and template removal,all occur in a spontaneous and orderly manner in the one-pot hydrothermal process.Investigations on structural evolution during the process reveal that pre-synthesized zeolitic imidazolate framework-8(ZIF-8)nanoparticles are first dissociated and then self-assembled into 3 D branched superstructures of ZnO as templates.Initial self-assembly is followed by coating of the glucose-derived carbonaceous materials and etching of interior ZnO by organic acids released in situ by hydrolysis of glucose.The 3 D-branched hollow architecture is shown to greatly enhance supercapacitor performance.The research described here provides guidance into the development of strategies for complex hollow carbonaceous architectures for a variety of potential applications.