High-temperature Carbonization Research Articles

Non-carbonization annealing toward regulation of cobalt-based organic–inorganic hybrids as advanced electrocatalysts for water splitting

High-temperature carbonization typically used in the preparation of advanced electrocatalysts poses significant challenges in preserving abundant functional groups essential for reactant adsorption and component stabilization. To address this, a solvothermal synthesis followed by non-carbonization annealing approach is proposed to fabricate a series of cobalt-based organic–inorganic hybrids derived from cobalt-based glycerate nanospheres (GNs). Notably, annealing in phosphorous and inert atmospheres preserves the solid nanospherical structure, whereas treatment in sulfur-rich environments results in the formation of hollowed nanospheres. Among these hybrids, phosphorized solid cobalt GNs (Co-P-GNs) exhibit the highest catalytic activity for hydrogen evolution reaction (HER), achieving a low overpotential of 152 mV at 10 mA cm−2. Meanwhile, sulfurized hollow cobalt-iron GNs (Co-Fe-S-HGNs) demonstrate good performance in catalyzing oxygen evolution reaction (OER), with a low overpotential of 273 mV at 10 mA cm−2. Both catalysts exhibit robust stability and maintain 100 % Faradaic efficiency during operation in electrolyzers for water splitting. The high performance not only stems from the well-dispersed phosphide and sulfide crystallites, offering ample catalytic active sites; but also benefits from the partially thermolyzed organic matrix enriched with heteroatoms and functional groups, which facilitates ion adsorption to initiate the reactions and tightly clenches loaded components to stabilize the active species.

Enhanced photo-thermal conversion in phase change materials by Cu-Zn Bi-metallic metal-organic framework and expanded graphite

Photothermal phase change materials (PCM) are employed for the efficient conversion and storage of solar energy. In this work, a Cu-Zn bi-metallic metal-organic framework (MOF) was synthesized and combined with expanded graphite (EG), followed by high-temperature carbonization to prepare the supporting material for polyethylene glycol (PEG). Through the high-temperature carbonization process, nano-metallic copper is uniformly dispersed on the surface of the EG, accompanied by the formation of a new porous structure resulting from the evaporation of Zn vapour. The nano metallic copper particles enhance the thermal conductivity and photo-thermal conversion efficiency of the composite PCM, while the porous structure generated by Zn vapour improves the adsorption capacity of PEG. The composite PCM demonstrated a high phase change enthalpy of 174.6 J/g and excellent thermal reliability, with only a 2.29 % reduction in enthalpy after 200 melting-freezing cycles. Additionally, the thermal conductivity of the composite PCM reached 6.096 W/(m·K) which is 26.1 times higher than that of pure PEG, while the photo-thermal conversion efficiency achieved was 88.69 %. These properties indicate that the PEG/EG/Cu-Zn-MOF derived carbon composite PCM has great potential for applications in solar energy storage and conversion.

Bimetallic MIL-88/Polyaniline Hybrid Hollow Structure: In-situ Synthesis and Enhanced Oxygen Evolution Reaction at High Current Densities.

Developing oxygen evolution reaction (OER) electrocatalysts in an efficient strategy, while maintaining high catalytic activity and stability under high current densities, remains a crucial problem. In this study, a bimetallic iron-cobalt phytic acid complex loaded with polyaniline hollow structure (FCP@PAn) was successfully constructed, via a progress of selective etching and surface modification in one step without high-temperature phosphating or carbonization. The as-obtained FCP@PAn required only 329 and 385 mV overpotentials at high current densities of 500 and 1000 mA cm-2, respectively, due to phytic acid and polyaniline incorporation and the coordinated effect of each component. Additionally, the FCP@PAn exhibited the lowest Tafel slope values of 44.6 mV dec-1 and was able to continuously operate for 120 h at 500 mA cm-2, displaying high catalytic activity and stability. Hence, the hollow structure of the conductive polymer and MOFs composites provided a new surface modification strategy for transition metal-based catalysts that are prone to dissolution or corrosion during the OER process, as well as for high current density applications.

Uncovering the Salt-Controlled Porosity Regulation in Coal-Derived Hard Carbons for Sodium Energy Storage.

Coal is a promising precursor of hard carbon (HC) anodes for sodium-ion batteries (SIBs), by virtue of resource abundance, low cost, and high product yield. However, the concomitant inorganic salt is usually recognized as impurities and plays an obscure and even contradictory effect on the regulation of pore structure in HCs. Herein, a two-step pyrolysis procedure to the representative salty coal is performed, in which the acid washing program is selectively inserted. It is illuminated that salt acts as a template or activating agent for the generation of open pores at low temperatures but inhibits the closure of pores during the following high-temperature carbonization. The optimized HC delivers a reversible capacity of 322.4 mAh g-1, a high plateau capacity of 192 mAh g-1, and an initial coulombic efficiency of 80%, outperforming to most coal-based HCs. Assembled with an NVPOF cathode, the full-cell exhibits a high energy density of 284.7 Wh kg-1. This work not only provides a systematic understanding of salt-dependent pore structure modulation but also practices a simple, cost-effective, and potentially scalable technique for the production of coal-based HCs.

Platan seeds-derived PSC/Ni/Co composite with multi-morphologies as tunable microwave absorber

Biomass and its derived carbon materials, due to their glorious application value in the field of microwave absorption, have sparked a new round of research boom. Hereinto, platan seeds-derived carbon-based materials (PSC), offspring from direct carbonization of platan seeds, were ulteriorly processed and subjected to high-temperature carbonization treatment to synthesis PSC/Ni/Co composite with diversified morphology and tunable microwave absorption performance. The effect of nickel and cobalt ion concentrations on the absorption performance of composite materials was investigated in depth. The optimum reflection loss value (RLmin) of PSC/Ni can reach −47.36 dB, while its effective absorption broadband (EAB) is 5.8 GHz, ranging from 12–17.8 GHz, covering almost the whole Ku band. Compared with PSC/Ni composites, PSC/Co fulfils greater advantages in thickness and bandwidth. As for PSC/Ni/Co, the sample exhibits the optimal performance when Ni and Co ions are at equal concentrations, with an RLmin of −48.3 dB and an EAB of 5 GHz (13–18 GHz), which congealed the edges of both. Unequivocally, the morphological polymorphism of carbon-based-derived microwave absorbing materials with platan seeds as the carbon source is crucial to harvset lightweight, efficient and adjustable absorption properties, let alone its relatively simple and feasible preparation method. This may provide a new approach for engineering light-weight, cost effective and eco-friendly absorbing materials.

Study on mechanical degradation of Ferrite/ martensite and austenitic steels in high-temperature supercritical carbon dioxide environment

The mechanical degradation mechanism of T91 ferrite/martensite steel at 500 °C and 316NG austenitic steel at both 500 °C and 600 °C in supercritical carbon dioxide were investigated in detail by slow strain rate tensile tests and first-principles calculations of the adsorption and dissociation of CO2. In high-temperature CO2 atmosphere, CO2 could spontaneously dissociate into CO and O, and the spontaneously and partially dissociated O atoms exhibited a strong interaction with Cr. As the temperature was increased to 600 °C, the partial dissociation of CO2 occurred more rapidly and the ultimate tensile strength and total elongation of 316NG steel decreased significantly as well. Furthermore, a composite failure mode with intergranular brittle fracture and ductile fracture was investigated.

High-temperature carbon dioxide capture in a porous material with terminal zinc hydride sites.

Carbon capture can mitigate point-source carbon dioxide (CO2) emissions, but hurdles remain that impede the widespread adoption of amine-based technologies. Capturing CO2 at temperatures closer to those of many industrial exhaust streams (>200°C) is of interest, although metal oxide absorbents that operate at these temperatures typically exhibit sluggish CO2 absorption kinetics and instability to cycling. Here, we report a porous metal-organic framework featuring terminal zinc hydride sites that reversibly bind CO2 at temperatures above 200°C-conditions that are unprecedented for intrinsically porous materials. Gas adsorption, structural, spectroscopic, and computational analyses elucidate the rapid, reversible nature of this transformation. Extended cycling and breakthrough analyses reveal that the material is capable of deep carbon capture at low CO2 concentrations and high temperatures relevant to postcombustion capture.

Pathways to Carbon Neutrality in Civil Engineering

Abstract. With the development of the global economy and trade exchanges worldwide, urban infrastructure and industrial development have become part of the competition among countries. However, the construction industry and the production of chemical materials emit a large amount of carbon dioxide, leading to the continuous deterioration of the environment, so it is necessary to effectively reduce emissions. As a synonym for global emission reduction, carbon neutrality plays an important role in different industries, especially in civil engineering. In this paper, we start with building materials and green construction to explore the realization of carbon neutrality at the source and center of carbon emission in civil engineering. Firstly, we introduce the low-carbon production technologies of cement and steel, including calcium recycling and membrane separation technology in the cement industry, high-temperature combustion technology and carbon capture technology in steel industry. Then, we take renewable concrete as an example to discuss the emission reduction path of green building materials. Finally, it outlines how to carry out green construction, introduces assembly carbon reduction technology and energy integration system, and demonstrates the possibility of this green construction program in the case of "T&A House".

Fabrication of surface-carbonated boron nitride nanosheets and their application as water-based lubrication additives

As a typical two-dimensional layered material, hexagonal boron nitride nanosheets (BNNSs) have high mechanical strength, good conductivity, and excellent lubrication performance, which have great potential as solid nano lubricant additives in tribology. When BNNS is used as a water-based or oil-based lubricant additive, its inherent chemical inertness and poor dispersion stability make it difficult to achieve optimal anti-friction and anti-wear performance. In this paper, a simple and efficient preparation method for obtaining hexagonal boron nitride nanosheets (C-HPC-BNNSs) with surface carbonization modification and excellent dispersion stability in water-based lubricants was proposed. Using hydroxypropyl cellulose (HPC) as a modifier, a wet ball milling process combined with high-temperature carbonization treatment effectively reduced the thickness of BNNSs while uniformly modifying N-doped carbon layers on the surface of the nanosheets. Benefit from the smaller layer thickness of C-HPC-BNNSs, they exhibit excellent dispersion stability in the water-glycol solution and can maintain no significant agglomeration behavior for up to 30 days, which is the basis for the excellent lubrication performance of lubricant systems. In addition, the N-doped carbon layer modified on the surface is beneficial for enhancing the hydrophilicity of BNNSs and synergistically enhances the tribological properties of the material with BNNSs. The test results of the four-ball friction tester show that compared with the pure water-glycol solution and the water-glycol system with added C-HPC-BNNSs, the friction coefficient (COF) and wear volume of the system with added C-HPC-BNNSs could be as low as 0.095 and 1.99 × 10−4 mm3, respectively. This work has positive significance for the preparation, surface modification, and tribological application expansion of two-dimensional layered material BNNSs, which is conducive to further understanding the relationship between.

COF-derived hierarchical porous N,O dual-doped carbon nanosheets towards efficient aqueous Zn-ion supercapacitor with long lifespan

Designing and precisely constructing novel carbon-based cathodes with a high specific surface area (SSA), excellent stability, and abundant active sites is critical for achieving high-performance zinc-ion hybrid capacitors (ZHCs). Covalent organic frameworks (COFs), a class of well-defined crystalline porous polymer materials, can integrate organic building blocks into highly ordered topological structure, offering a robust platform for specific structural design and versatile functional exploitation. In this study, hierarchical porous carbon nanosheets (PCs) with high conductivity and abundant heteroatom doping were synthesized through an in situ polycondensation reaction followed by high-temperature carbonization. This unique structure facilitates the diffusion of electrolyte ions and the adsorption/desorption of Zn2+ ions. As a result, the optimized PC-1000 electrode demonstrates a high specific capacity of 168.9 mAh g−1 at 0.1 A g−1 and remarkable stability, maintaining a high capacity retention rate of 102.5 % after more than 50,000 cycles at 10 A g−1, outperforming other PC-based materials reported in the literature. This work provides an effective way for developing carbon-based cathode materials for high-performance energy storage devices.

Photothermal evaporation of pure, saline, muddy, and dye-contaminated waters using carbon black@PDMS sponges with superhydrophilic surface

This study aimed to develop a carbon black (CB)@ polydimethylsiloxane (PDMS) sponge capable of highly efficient photothermal water evaporation. The sponge was fabricated through a straightforward method that did not entail a high-temperature carbonization process, utilizing a sugar cube as a sacrificial template to create a porous structure, followed by CB incorporation into the PDMS matrix. A polyvinyl alcohol (PVA) coating was used to enhance the hydrophilicity of the sponge, resulting in improved water absorption and distribution. The photothermal performance of the PVA-coated CB@PDMS sponge was evaluated using various contaminated water types, including seawater, muddy water, and Rhodamine-B-contaminated water. The sponge demonstrated water-evaporation rates ranging from 3.28–4.38 kg/m²·h, significantly reducing the water-evaporation enthalpy and effectively preventing salt precipitation during seawater desalination. Additionally, it maintained its performance over repeated experiments and demonstrated efficiency improvement over multiple cycles, indicating that its effectiveness increased with repeated use, likely because of surface conditioning and structural stabilization. Moreover, the water recovered from seawater, muddy water, and dye-contaminated water was free of trace contaminants, thereby yielding clean water and demonstrating the suitability of the sponge for water purification and desalination applications.

The Fabrication of ZIF-L Derived Zns/Mos2@NC Anode Materials for Remarkable Lithium-Ion Storage.

The enhancement of electrochemical performance in lithium-ion batteries can be achieved through the incorporation of MoS2 with carbon materials and various metal sulfides. In this study, a ZnS/MoS2 heterostructure was developed, featuring a two-dimensional nitrogen-doped carbon nanosheet (NC) backbone. The synthesis of ZnMoZIF-L precursors was accomplished by introducing a Mo source in a 1 : 1 molar ratio during the ZIF-L synthesis process. Following high-temperature carbonization and vulcanization treatment, ZnS/MoS2@NC composite materials were successfully synthesized. Compared to the unvulcanized ZnO/MoO3@NC and MoS2 samples, the ZnS/MoS2@NC composite exhibits remarkable lithium storage performance. At a current density of 500 mA g-1, the initial reversible capacity capacity is still as high as 1674 mAh g-1. Furthermore, this composite material demonstrates optimal rate capabilities and a significant contribution to pseudocapacitance. The nitrogen-doped carbon framework effectively mitigates volume changes, while the heterostructural design provides more active sites for lithium-ions, thereby enhancing lithium storage performance.

Technology Focus: EOR Operations (November 2024)

International agreements and national policies on environmental sustainability are changing the outlook for enhanced oil recovery (EOR) globally. These changes are highlighted by both monetary and intellectual commitments by oil companies around the world. Saudi Aramco has pledged $1.5 billion toward sustainable technology. In practice, members of Aramco’s EXPEC Advanced Research Center have collaborated with King Fahd University of Petroleum and Minerals to develop sustainable surfactants for use in high-temperature, high-pressure, and high-salinity carbonate reservoirs. They used no or only green solvents to produce soluble, stable surfactants with the potential for biodegradability. In Colombia, Ecopetrol is committed to reducing CO2 emission by 25% by 2030. As part of its efforts, it has been optimizing polymer injection in Chichimene, a heavy-oil field. By estimating life cycle greenhouse-gas emissions and energy consumption, it was able to show that polymer injection and its associated carbon intensity reduction could prevent the emission of 3,200 tons CO2 equivalent. To comply with the UK’s North Sea Transition Deal, which mandates a 50% reduction in offshore oil and gas emissions by 2030, Ithaca Energy and Energy Research Norway is using life-cycle assessment to guide more efficient heavy-oil recovery. By using low-dose polymer injection, instead of alternatives such as thermal EOR, it was able to increase exergy while also reducing CO2 emissions by 35%. In these studies, we already see the effect of the energy transition as companies turn away from traditionally effective but environmentally burdensome EOR methods such as steam injection and new polymers that show equal, if not greater, effectiveness with a reduced environmental cost. As we move forward with further regulation and innovation, it will be interesting to see how emerging technological developments in polymers, nanofluids, and even artificial intelligence can help producers meet both the economic and environmental criteria to maintain profitable fields. Recommended additional reading at OnePetro: www.onepetro.org. SPE 218653 Coinjection EOR Technology Increases Recovery and Reduces Greenhouse-Gas Emissions by G. Wasylchuk, GERI SPE 218690 Steam Generation Using Renewables Energy—An Integrated Approach for Enhanced Oil Recovery Applications by Mustafa Al Ajmi, Petroleum Development Oman, et al. SPE 218962 Reaching a Million Barrels in an Abu Dhabi Field by Focusing on Operations Efficiency by Masud J. Akhtar, Abu Dhabi National Oil Company, et al.

Experimental investigation on fracture propagation in shale fractured by high-temperature carbon dioxide

The productivity of shale reservoirs was significantly enhanced by the high-temperature CO2 fracturing technique. The injection of high-temperature CO2 into the formation induced rock fracture propagation, creating advantageous pathways for fluid flow. In this research, a self-developed in situ high-temperature convective heat simulation experimental apparatus was employed to systematically conduct simulated experiments on high-temperature CO2 fractured shale under different influencing factors. The experimental results demonstrated that the permeability of CO2 increased as the injection temperature increased. The rock fracture pressure was effectively reduced by high-temperature CO2 fractured shale. Higher complexity was observed in fracture propagation, accompanied by a substantial increase in microcracks and branching fractures. The shale fracture pressure increased with increasing triaxial stress and CO2 injection rate. The confining pressure restricted the further propagation of fractures under relatively high stress conditions, thereby reducing the width and density of fractures, lowering the fracture complexity. Nevertheless, the thermal shock effect of the fluid was exacerbated as the injection rate of high-temperature CO2 increased. The initiation of microcracks was facilitated by the intensification of local thermal stress in shale, inducing multiple curved fractures and forming a more complex fracture network. Compared to horizontal bedding shale, the fracture pressure of vertical bedding shale was relatively higher during high-temperature CO2 fracturing. In addition, the geometric morphology of fracture propagation was more complex, characterized by rougher fracture surfaces, leading to a greater improvement in reservoir reconstruction volume. This research contributed to the optimization of CO2 resource utilization, provided experimental evidence for the application of high-temperature convection fracturing technology in in situ shale conversion projects.

Visible Opacities of S-type Stars: The d 3Φ–a 3Δ Band System of ZrO

ZrO is a well-studied metal monoxide because of its astrophysical importance in characterizing S stars. The bands of the d 3Φ–a3Δ system (γ system) with v′≤4 and v″ ≤ 5 are rotationally analyzed using the PGOPHER program to provide spectroscopic constants. The high-resolution ZrO emission spectrum was recorded with a Fourier transform spectrometer using a high-temperature carbon furnace source. New ab initio calculations of the transition dipole moment were carried out in order to determine the vibronic band strengths. The spectroscopic constants, along with the band strengths, are used to calculate a line list for the γ system. This line list can be used to determine Zr abundances in S stars. We also correct the line strengths for the B 1Π–A 1Δ transition calculated in our previous work.

In situ catalyzed growth of carbon nanotube with asphalt cladding as a bicarbon synergistic framework of silicon anodes for lithium-ion batteries.

Silicon, as the most promising advanced anode material for lithium-ion batteries, faces challenges in large-scale industrial production due to the significant volume expansion effect. In this investigation, Si/CNTs/C composite materials were effectively produced through high-temperature carbonization utilizing asphalt, silicon, hexahydrate ferric chloride, and melamine as primary elements. The distinctive dual-carbon framework of asphalt-derived carbon and carbon nanotubes alleviates the volume expansion of silicon, thereby stabilizing the composite material's structure. Testing the electrochemical performance reveals that the Si/CNTs/C composite material exhibits a reversible specific capacity of 1187 mAh g-1 with a capacity retention rate of 92.6% after 150 cycles at a current density of 0.2 A g-1. Even after 500 cycles at a current density of 1 A g-1, it sustains a specific capacity of 879.4 mAh g-1 with a capacity retention rate of 87.9%, showcasing outstanding electrochemical performance.

Innovative Multielement Modification of Pitch-Derived Two-Dimensional Carbon Nanosheets as Anodes for Superior Performance Sodium-Ion Batteries.

The development of advanced anode materials for sodium-ion batteries (SIBs) using pitch-based carbon materials has the advantages of low cost, high electrical conductivity and easy structural modification. In this research, various well-established modification techniques for petroleum pitch are integrated, including the use of recrystallized NaCl as molten salt template, pretreatment and high-temperature carbonization under a pure oxygen atmosphere, and the introduction of heteroatoms (N and S) by hydrothermal methods. The resulting two-dimensional carbon nanosheets with multielement modification exhibit enhanced Na+ storage properties, thereby bringing higher cycling stability and superior rate performance. Due to its specific structure and chemical composition, NS-P-OPDC exhibited a high reversible capacity of 406.77 mAh g-1 at a current density of 100 mA g-1 and a superior rate performance of 193.20 mAh g-1 at a current density of 3 A g-1 after being applied to the anode of SIB half-cell. Especially, a capacity retention of 97.7% was still achieved after 4000 cycles. Meanwhile, the full-cell assembled by Na3V2(PO4)3 (NVP) cathode and NS-P-OPDC anode could provide a reversible capacity of 235.30 mAh g-1 at a current density of 300 mA g-1. This application proves to advance petroleum pitch-based high-performance electrodes toward greater efficiency in electrochemical energy storage.

Hierarchical MoO2@MoS2 heterojunction nanosheets anchored with metal-organic framework-derived CoFe alloy as bifunctional catalysts for flexible zinc-air batteries

Crafting a robust, high-performance, non-precious metal-based flexible air electrode is crucial for realizing flexible zinc-air batteries (ZABs). Herein, hierarchical MoO2 and MoS2 heterojunction nanosheets grown on carbon cloth (CC) are prepared through a simple hydrothermal reaction followed by calcination. Afterward, through self-assembly and high-temperature carbonization of zeolitic imidazolate framework-67 (ZIF-67) and Materials of Institute Lavoisier-101 (MIL-101) on the heterojunction nanosheets, a hierarchical structure of nitrogen-doped carbon (NC) encapsulated CoFe alloy nanoparticles (NPs) supported on MoO2@MoS2 heterojunction nanosheets (CC/MoS2@MoO2@CoFe) is obtained. It exhibits remarkable activity and durability for both bifunctional oxygen evolution and reduction reactions (OER/ORR), attributed to the ternary heterojunction formed by NC-coated CoFe alloy NPs uniformly dispersed among the MoO2@MoS2 nanosheets, along with oxygen vacancies at heterogeneous interfaces between MoS2, MoO2, and Co0.72Fe0.28 alloy. As a binder-less self-supporting electrode, the assembled aqueous ZAB demonstrates a maximum power density of 113.6 mW cm–2, surpassing that of Pt/C + RuO2 (75.2 mW cm–2), along with excellent cycling stability. Furthermore, the CC/MoS2@MoO2@CoFe-based flexible ZABs achieve a maximum power density of 54.1 mW cm–2, exhibit good cycling stability for up to 120 cycles, and show outstanding flexibility. This study paves the way for the practical integration of flexible ZABs into wearable electronic devices, heralding a new era of portable power solutions.

Interface Engineering Induced by Low Ru Doping in Ni/Co@NC Derived from Ni-ZIF-67 for Enhanced Electrocatalytic Overall Water Splitting.

Electrochemical water splitting is a promising approach for hydrogen evolution reactions (HER); however, the oxygen evolution reaction (OER) remains a major bottleneck due to its high energy requirements. High-performance electrocatalysts capable of facilitating HER, OER, and overall water splitting (OWS) are highly needed to improve OER kinetics. In this work, we synthesized a trimetallic heterostructure of Ru, Ni, and Co incorporated into N-doped carbon (denoted as Ru/Ni/Co@NC) by first synthesizing Ni/Co@NC from Ni-ZIF-67 polyhedrons via high-temperature carbonization, followed by Ru doping using the galvanic replacement method. Benefiting from increased active surface sites, modulated electronic structure, and enhanced interfacial synergistic effects, Ru/Ni/Co@NC exhibited exceptional electrocatalytic performance for both HER and OER processes. The optimized Ru/Ni/Co@NC catalyst, with a minimal Ru mass ratio of ∼2.07%, demonstrated significantly low overpotential values of 34 mV for HER and 174 mV for OER at a current density of 10 mA/cm2 with corresponding Tafel slope values of 33.42 and 34.39 mV/dec, respectively. Further, the optimized catalyst was loaded onto carbon paper and used as anode and cathode materials for alkaline water splitting. Interestingly, a low cell voltage of just 1.44 V was obtained. The enhanced electrolytic performance was further elaborated by density functional theory (DFT) calculations, which confirmed that Ru doping in Ni/Co introduced additional active sites for H*, enhancing adsorption/desorption abilities for HER (ΔGH* = -0.30 eV), lowering water dissociation barrier (ΔGb = 0.49 eV) and reducing the energy barrier for the rate-determining step of OER (O* → OOH*) to 1.62 eV in an alkaline environment. These findings reflect the significant potential of ZIF-67-based catalysts in energy conversion and storage applications.

Regulation plateau capacity and initial coulombic efficiency of furfural residues-derived hard carbon via components engineering

The scale-up application of biomass-based hard carbon (HC) in sodium-ion battery (SIB) is hampered by low initial coulombic efficiency (ICE) and specific capacity, especially for the plateau capacity. By taking advantage of furfural residues (FRs), which are mainly constructed with lignin and cellulose, a component modulation engineering strategy is adopted to prepare high performance HC. In this work, the microstructure of FR-derived HCs can be well-regulated after component modulation. Specifically, the introduction of oxygen functional groups during low-temperature oxidation process promotes the recombination of cellulose and lignin in FRs and produces more C=O in oxidized FRs, which is favorable to suppress the carbon structure from melting and rearranging during the high-temperature carbonization process, leading to a well-balanced pseudo-graphitized/disordered microstructure and excellent corresponding electrochemical performance. Experiment results reveal that the sample underwent component engineering delivers a high capacity of 302.5 mAh g−1 and excellent ICE of 90.9 %, which are higher than that of the sample direct carbonized (225.0 mAh g−1 and 75.6 %). Notably, the plateau capacity increases from 147.0 mAh g−1 to 204.2 mAh g−1, accounting for nearly 100 % of the reversible capacity increase. Our work provides a new insight of microstructure regulation of biowaste-based HC with high electrochemical performance.