Herein, we demonstrate an efficient valorization of rubber fruit shell waste (RFSW) as an abundant agricultural byproduct into activated carbon (AC) through a sequential multi-step KOH/CO2 activation. The RFSW-700 sample (synthesized at 700 °C) exhibits a large specific surface area exceeding 494 m2/g, high carbon content, a predominantly disordered carbon framework, and high proportion of graphitic ordering. The RFSW-700 achieves a specific capacitance of 229 F/g and delivers an energy density of 7.52 Wh/kg. The RFSW-700 electrode retains 88.8
Boron-doped reduced graphene oxides (B-rGO) were prepared by thermally treating GO with boric acid in argon at temperatures above 1300°C. Oxidized boron species formed at low temperatures progressively converted into substitutional BC3 above 1500°C, where they were incorporated into the sp² lattice. Boron also promoted the formation of closed-loop edge structures, thereby stabilizing high-energy open sites. Although substitutional boron atoms were incorporated into the sp2 framework, they induced localized distortions in both the lattice symmetry and the electronic environment. Accordingly, Raman spectra showed an intense D band and a suppressed G’ band, while XPS analysis revealed a reduced sp2/sp3 ratio, collectively indicating that boron functions as a defect in both optical and electronic terms. These BC3 dopants, particularly at looped edges, covalently linked graphene layers, increasing both the oxidation onset temperature and domain conductivity. Although edge looping increased interparticle resistance to some extent, B-rGO samples still exhibited higher overall conductivity than undoped rGO. Theoretical simulations further supported the mechanism, showing that substitutional boron at armchair edges enhanced peroxide ion adsorption through electron transfer. In contrast, looped-edge configurations exhibited weak peroxide binding, suggesting improved oxidation resistance through the reduced edge-reactivity. Taken together, these results reveal a direct link between boron doping, edge stabilization, and functional enhancement, and provide a strategy for designing high-performance carbon materials for energy and environmental applications.
Concerns over the environmental impact, supply chain vulnerability, and long-term availability of conventional lithium-ion battery (LIB) materials have intensified interest in sustainable alternatives. This review defines a fully sustainable battery as one in which all components are derived from renewable materials and produced through eco-friendly processes across their entire lifecycle, consistent with the ISO 14044:2006 LCA framework. The current state of partially sustainable batteries is evaluated against this definition through a critical review of recent advances in biomass-derived carbon anodes, organic cathode materials, biopolymer gel electrolytes, cellulose-based separators, bio-derived binders, and carbonaceous current collectors across lithium-ion, sodium-ion (SIB), and aqueous zinc-ion (ZIB) battery chemistries. Key findings include the cost and carbon footprint competitiveness of biomass-derived hard carbon anodes with synthetic graphite (1.72 kg−1 vs4.97 kg−1; 3.2 vs 25.1 kg CO₂-eq kg−1), the ionic conductivity competitiveness of biopolymer gel electrolytes with conventional liquid electrolytes (up to 11 mS cm−1), and the consistent superiority of cellulose-based separators over commercial polypropylene in thermal stability, electrolyte wettability, and biodegradability. This review makes an original contribution by identifying four challenges that prevent the integration of these components into a fully sustainable battery. The costs, sustainability, and lifecycle assessments of LIBs, SIBs, and ZIBs are comparatively evaluated using available LCA data, and prospects for sustainable battery recycling are assessed. Based on this analysis, five research directions are proposed, with SIBs and aqueous ZIBs identified as the most viable configurations for fully sustainable batteries given their compatibility with bio-derived materials and lower lifecycle environmental impact.
Three-dimensional vertical graphene (VG) possesses a high surface area and an edge-oriented architecture, making it a promising electrode material for electrochemical energy storage applications. In this study, nitrogen-doped VG (N-VG) films were synthesized via an in-situ microwave plasma process, and the effects of nitrogen doping and Cu substrate crystallinity on the structural, chemical, and electrochemical properties of VG were systematically investigated. The growth conditions for pristine VG in a CH4–H2 plasma were first optimized and used as a baseline for the nitrogen incorporation. The introduction of N2 during growth preserved the vertically oriented graphene morphology while inducing distinct changes in defect characteristics and bonding configurations. Raman spectroscopy revealed progressive increases in the ID/IG and ID′/IG ratios with increasing nitrogen incorporation, indicating enhanced defect density and localized bonding perturbations within the sp2 carbon lattice. X-ray photoelectron spectroscopy confirmed successful nitrogen incorporation, with graphitic (quaternary) N identified as the dominant bonding configuration. Electrochemical analyses using a PVA–H3PO4 gel electrolyte demonstrated that nitrogen doping, particularly when combined with a single-crystalline Cu substrate, reduced charge-transfer resistance and enhanced the charge accumulation behavior, leading to improved electric double-layer capacitor performance with excellent cycling stability. These results elucidate the role of in-situ nitrogen doping in modulating the defect characteristics and electronic structure of VG and provide insights into the structure–electrochemical property relationships of N-VG for use as an electrode material for solid-state electric double-layer capacitors (EDLCs).
This paper uses bamboo powder as the carbon source and prepares bamboo-based porous carbon through KOH activation and high-temperature carbonization. High specific surface area and rich pore structure are the basic properties of this type of material, creating favorable conditions for the introduction of oxygen vacancies. Electron paramagnetic resonance analysis confirmed that abundant oxygen vacancies were successfully introduced into the material, strengthening its adsorption and activation of oxygen, thereby effectively enhancing the oxygen reduction catalytic activity. Through wastewater testing in the laboratory, biomass porous carbon materials are used as electrodes for cathode catalysts, and its electrochemical detection reaches 234 mW m− 2, demonstrating excellent electrochemical performance. In the wastewater treatment test, the chemical oxygen demand removal rate reached 86
Porous carbons have attracted extensive research attention as electrode materials for supercapacitors. However, an amorphous carbon structure can be generated during the intense pore formation process, which restricts the rate capability of carbon electrode. Coal, an abundant low-cost precursor with aromatic structures and graphite microdomains, is mainly used for combustion which causes pollution and coal-based carbons have drawbacks of low porosity and mismatched solvated ion/micropore size. N/O co-doping can stabilize short-range order and enhance electroactivity. Herein, N/O co-doped short-range ordered amorphous carbons (CUx−700) were synthesized via one-step pyrolysis using anthracite as carbon source, urea as nitrogen source. By varying the added dosage of urea, the porosity, heteroatom content and short-range ordered graphitization structure of the carbon materials were regulated. The optimal CU0.2−700 endowed with high graphitization (ID/IG = 0.96), abundant micro- and mesopores and 16.91 at
Two-dimensional (2D) porous carbon nanosheet materials possess a large specific surface area, readily accessible interface and abundant active sites, and exhibit great potential in the field of energy storage. Herein, we introduce an antisolvent precipitation strategy for creating precursors to produce 2D carbon nanosheet materials with high specific surface area. The samples without antisolvent (PC) formed a block-like porous structure, while the samples with antisolvent (NPC) formed a carbon nanosheet structure that effectively prevented structural collapse. The nitrogen and oxygen functional groups can provide some pseudocapacitance and improve wettability. Influenced by the collaborative effects, the optimized porous carbon nanosheet electrode (NPC-600) displays a specific capacitance of 420 F g−1 and superior electrochemical stabilization. More importantly, the resulting Zn//ZnSO4//NPC-600 zinc-ion hybrid capacitor achieves a high reversible specific capacity of 211.66 mAh g−1 and an areal capacity of 0.43 mAh cm−2 at 0.1 A g−1, a high energy density of 169.33 Wh kg−1, and outstanding long-term cycling stability (10,000 cycles, 84.21
Bi-based compounds are increasingly recognized as potential anodes materials for potassium-ion batteries (PIBs), because of their exceptional theoretical capacity and appropriate operating potential characteristics. In this work, we introduced Bi@N-doped carbon composite comprising nanoscale Bi particles encapsulated within a nitrogen-doped carbon (Bi@NC) matrix framework. This distinctive configuration is attained through an in-situ carbonthermal reduction strategy. The N-doped carbon layer restricted Bi particle, the restricted domain microenvironment not only inhibits possible agglomeration and oxidation problems at the active site, but also makes intermediates, reactants and products more easily transferable within the restricted domain space. Consequently, the structure of Bi@NC facilitates rapid potassium storage, achieving a remarkable 253.3 mAh g− 1 capacity at 1 A g− 1, along with consistent cycling stability, retaining 170.3 mAh g− 1 capacity at 10 A g− 1 following 500 cycles. Importantly, a full cell featuring a potassium vanadate (Ca-KVO) cathode shows substantial promise for real-world applications. An extensive range of ex-situ methods are utilized to clarify the intricate potassium storage processes and kinetic characteristics. This research offers valuable perspectives for advanced PIBs.
In diamond growth using microwave plasma chemical vapor deposition (MPCVD) process, the methane fraction controls the balance between carbon supply and hydrogen etching, while substrate temperature governs surface diffusion and facet‑dependent growth. Yet for polycrystalline diamond (PCD) films used as optical windows and heat spreaders, the combined influence of these two parameters is rarely quantified across multiple, cross‑validated metrics. Here we isolate the role of CH4 at fixed temperature by growing PCD on identically prepared Si (100) wafers with all parameters held constant except the methane fraction (4 to 8
In recent years, there has been considerable interest in surface engineering using carbon-based coatings to improve pyroelectric performance. This work demonstrates a straightforward, economical method for a pyroelectric energy generator (PEG) using candle soot as a light-absorbing coating on a widely available PZT-based piezoelectric buzzer. Infrared (IR) lamp-induced thermal excitation was used to comprehensively assess the performance of the soot-coated and pristine PZT piezoelectric buzzer disk. Due to improved photothermal conversion, the coated PEG device exhibits a significant increase in electrical output. When exposed to the IR lamp, the short-circuit current reached approximately 204 nA, while the open-circuit voltage was approximately 4.8 V. Furthermore, under controlled thermal cycling, the device exhibited adjustable output and efficient energy storage. Further, the PEG was shown to be sensitive to temperature changes caused by human activity or the daily use of appliances, as well as to energy harvesting, suggesting its potential for self-powered sensing applications, such as breath monitoring, or converting energy from everyday appliances. Overall, this study presents a simple method to increase pyroelectric device performance efficiency in sensing and sustainable energy applications.
With the increasing environmental concerns for petroleum-based epoxy resins, the development of low-carbon epoxy systems has increased. The traditional epoxy resins are extremely carbon intensive because of the high curing energy and base material as petroleum derived product. Thus, sustainable alternatives are being studied such as green curing methods, bio-based hardeners, solvent free processes, renewable reinforcements and bio-based epoxies from vegetable oils, lignin and sugars. The current review highlights an extensive investigation into major emission sources that arise during the production and manufacturing of epoxy resins and composites. Various emissions from fossil fuel-based precursors, hardeners, process-related energy consumption, and reinforcing substances have been analysed in detail. Furthermore, various novel approaches to achieve low-emission epoxy resins by employing bio-derived precursors, renewable resources, green and bio-based curing agents, energy-saving and solvent-free manufacturing processes, as well as natural or recycled reinforcements have been reviewed. Besides, the review provides an overview of the state-of-the-art research on the LCA of bio- versus petroleum-based epoxy systems, compares their carbon footprints and energy consumption, and presents case studies and sustainability databases. Circular strategies of epoxy resins are another significant focus of the paper, as it highlights the importance of recyclability and reprocessability of thermosets, dynamic covalent and vitrimeric epoxy networks, and epoxy resins’ degradation and recycling methods. Major GHG emission sources in epoxy and composite manufacturing analyzed. Bio-based epoxy precursors from renewable feedstocks comprehensively reviewed. Solvent-free and energy-efficient curing methods for epoxy fabrication highlighted. LCA, carbon footprint, and sustainability of epoxy systems critically evaluated. Circular epoxy technologies including vitrimers and recyclable thermosets discussed.
The separation performance of polyamide (PA) membranes is governed by their cross-linking structure, a critical parameter dictated by the diffusion kinetics of 1,3-phenylenediamine (MPD) during interfacial polymerization. Herein, we introduce sodium dodecyl sulfate (SDS) into the aqueous phase to construct a strong, short-range hydrogen-bonding network with MPD molecules. This interaction effectively impedes MPD diffusion to the biphasic interface, thereby promoting the formation of a highly cross-linked PA structure. Consequently, the optimized S-PA membrane exhibits a more uniform network structure and a narrower pore size distribution. The results show that the membrane achieves water permeance of 13.5 L m− 2 h− 1 Mpa− 1 coupled with a NaCl rejection exceeding 97.1
The design and fabrication of high-performance supercapacitors requires innovative materials with unique energy storage capabilities. Herein, a novel Nucleosome like MnFe2O4@TiO2@MWCNTs composite is fabricated and considered for its potential in energy storage applications. The synthesis and structural parameters of composite materials are inspected through XRD (X-ray diffraction), SEM (Scanning electron microscopy) and TEM (Transmission elctron microscopy). High resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS) and energy dispersive x-ray spectroscopy (EDX) analyses are also used as further confirmation tools. Cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) techniques are used to estimate the electrochemical properties. The composite delivered a maximum specific capacitance of 786.26 F g− 1 at 2.5 mA in a two-electrode configuration. The assembled MnFe₂O₄@TiO₂@MWCNTs device showed maximum energy density of 33.03 Wh kg⁻¹ at a power density of 458.47 W kg⁻¹. These results demonstrate the composite potential for advance energy storage devices.
In this study, we prepared a carbon-coated prelithiation additive to replenish lithium ions lost to solid electrolyte interphase formation during the initial charge–discharge process. After mixing LiOH and FePO4 in various weight ratios, Li3PO4–Li5FeO4 composites were synthesized through a two-step heat treatment involving precursor hydrolysis and a solid-state reaction. To improve the surface stability of the synthesized composites, a carbon coating was applied via chemical vapor deposition using acetylene as the carbon source. The physical properties of the mixed-phase composites were analyzed using scanning electron microscopy(SEM), energy-dispersive X-ray spectroscopy(EDS), X-ray diffraction(XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy(XPS). The electrochemical properties were analyzed by charge–discharge cycling, rate capability tests, differential capacity(dQ/dV) analysis, and electrochemical impedance spectroscopy(EIS). The NCM811 cathode containing the prelithiation additive prepared at a LiOH/FePO4 weight ratio of 11:1 exhibited the highest initial capacity of 242.3 mAh/g, corresponding to a 7.7
Atmospheric pollution has been increasing because of the rapid expansion of industrial and related activities. This growing pollution significantly affects human health and contaminates consumable resources. In particular, aerosol particulate matter plays a critical role in deteriorating air quality and poses serious health risks. Efforts to use these waste materials as a sustainable approach to reducing environmental pollution have recently gained attention. Atmospheric dust particles can serve as a valuable source of carbon-based materials through simple and efficient conversion methods. These dust particles, which often carry various metal ions, can yield functional carbon materials suitable for diverse applications. Similarly, waste spider web fibers commonly found in households contain adsorbed inorganic nanoparticles and represent another potential source of carbon. These micro-sized particles can be transformed from hazardous pollutants into useful materials if properly processed. This study reports a facile method for converting waste aerosol dust particles and spider web fibers collected from residential areas into functional carbon products. The morphological, structural, chemical, and optical properties of the resulting fibrous carbon were characterized using SEM, XRD, UV-vis, Raman, PL, and BET techniques. The results demonstrated that carbon materials derived from dust and spider webs exhibit reasonably good properties, highlighting their potential for CO2 sensing and electrochemical energy storage applications. This waste-derived carbon fiber can be processed further to improve its quality comparable to those of commercial carbon fibers.
Lithium metal anodes suffer from unstable interfacial behavior during repeated cycling, which limits their application in high-energy-density batteries. Herein, an AlN-PVDF composite layer was fabricated on Li metal anodes via a spray-coating process, and its influence on electrochemical performance was investigated. The AlN-PVDF coating did not alter the initial charge/discharge behavior of the cells. Compared with bare Li metal anodes, cells employing the AlN-PVDF@Li anode exhibited a smaller charge/discharge voltage hysteresis and improved cycling stability. In full cells assembled with NMC622 cathodes, the AlN-PVDF@Li anode retained approximately 116 mAh g− 1 after 200 cycles at 5 C, corresponding to a capacity loss of 20
The increasing demand for sustainable, high-performance energy storage technologies has intensified research into electrode materials that combine environmental compatibility with superior electrochemical properties. MXenes, a diverse family of two-dimensional transition metal carbides and nitrides, exhibit metallic conductivity, tunable surface terminations, and pronounced pseudocapacitive behaviour. In contrast, biomass-derived carbons offer hierarchical porosity, chemical stability, renewability, and cost-effective production from abundant waste resources. Integrating these materials has emerged as an effective strategy for developing next-generation supercapacitors with high capacitance, rapid charge–discharge kinetics, and long-term cycling stability. This review presents a comprehensive overview of the fundamentals of MXenes and biomass-derived carbons, synthesis methods for MXene/biomass-carbon hybrids, their structural and physicochemical properties, and recent trends in electrochemical performance. The synergistic combination of MXene conductivity and biomass carbon porosity is emphasized, as is the importance of interfacial engineering in improving ion transport and electrode stability. Major challenges, such as MXene oxidation, nanosheet restacking, variability in biomass carbon precursors, and environmentally hazardous synthesis processes, are critically assessed. The review concludes by identifying future research directions, including the development of oxidation-resistant MXenes, environmentally friendly, scalable fabrication techniques, enhanced interfacial coupling, and advanced mechanistic insights through in-situ characterization. Collectively, this work underscores the significant potential of MXene/biomass-derived carbon hybrids as sustainable and high-performance electrode materials for next-generation supercapacitor technologies.
The accumulation of antibiotics in the environment and their increasing ecological risks make it essential to develop efficient and cost-effective technologies for treating refractory antibiotics-containing wastewater. Compared with conventional physical adsorption and biodegradation, electrochemical advanced oxidation processes (EAOPs) offer advantages including simple operation, free of additional chemicals, mild reaction conditions, and the ability to achieve both pollutant degradation and resource recovery. The carbon-based membrane shows great potential to be applied as a catalytic electrode, performing functions as conventional supports. This study fabricated self-supporting carbon nanofibrous membranes modified with phenolic resin (PR) by an electrospinning-thermal treatment strategy. The structural, conductivity, and mechanical properties of membranes prepared by four PR loading methods (immersion, spray coating, blend electrospinning, and grinding-remolding) were systematically studied. Owing to its superior conductivity and mechanical strength, the PR-I@PTA/ACFs-10 membrane prepared by the immersion method was selected as the working electrode in a flow-through electrocatalytic system for degrading tetracycline (TC). This configuration forces the reaction solution through the anode and cathode, significantly enhancing convective mass transfer and reactant contact. The results indicate that under conditions of 2.5 V, pH = 6, and 10 mM Na2SO4, the degradation rate of 10 mg L-1 TC reached 85.07
Si–C composite anodes have recently attracted considerable attention as high-performance anode materials for lithium-ion batteries. This study was aimed at establishing a facile method for synthesizing Si–C composite anodes, based on co-pyrolysis of petroleum residue oil and Si nanoparticles. The Si content was varied to identify the limits of Si incorporation. Anisotropic carbon with evenly dispersed silicon was successfully produced, and the threshold beyond which silicon aggregation degrades carbon anisotropy was identified. The anisotropic carbon–silicon nanocomposite anode displayed a high specific capacity of 459.1 mAh/g, excellent rate capability at 1000 mA/g, and superior cyclability. Excessive addition of silicon nanoparticles led to reduced cyclability and rate capability. Overall, this study provides an effective method for producing Si–C composite anodes with enhanced electrochemical performance.
