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In this study, a novel fluorine-containing carbon nanosphere was synthesized by high-temperature carbonization of waste fluororubber trimmings, and its mixing method with fluororubber was investigated. It was found that the solution mixing method resulted in the highest tensile strength (7.6 %) and modulus at 100 % strain (13.3 %) of fluororubber compared to the mechanical mixing method. Furthermore, the addition of fluorine-containing carbon nanosphere can significantly enhance fluororubber's heat resistance, inhibit its thermal degradation, and increase its ultimate service temperature (266.3 °C, 2 years). This work provides new insights into the preparation of high-performance fluororubber composites.

Abstract The development of highly efficient electrocatalysts for direct seawater splitting with bifunctionality for inhibiting anodic oxidation reconstruction and selective oxygen evolution reactions is a major challenge. Herein, we report a direct seawater oxidation electrocatalyst that achieves long-term stability for more than 1000 h at 600 mA/cm2@η600 and high selectivity (Faraday efficiency of 100%). This catalyst revolves an amorphous molybdenum oxide layer constructed on the beaded-like cobalt oxide interface by atomic layer deposition technology. As demonstrated, a new restricted dynamic surface self-reconstruction mechanism is induced by the formation a stable reconstructed Co-Mo double hydroxide phase interface layer. The device assembled into a two-electrode flow cell for direct overall seawater electrolysis maintained at 1 A/cm2@1.93 V for 500 h with Faraday efficiency higher than 95%. Hydrogen generation rate reaches 419.4 mL/cm2/h, and the power consumption (4.62 KWh/m3 H2) is lower than that of pure water (5.0 KWh/m3 H2) at industrial current density.

Fluororubber (FKM) is an irreplaceable sealing material that plays a critical role in new energy vehicles, petrochemical and aerospace industries. Their broad applications arise from the excellent thermal stability and solvent resistance of fluororubber. Despite there are increasing number of reports on preparation methods, properties and characterization of FKM in literature, there is still a lack of a thorough and comprehensive review that summarizes these results. This paper provides an overview of FKM types, preparation methods, property testing and microscopic characterization, and attempts to give a comprehensive introduction to the vulcanization mechanism of FKM using ternary fluororubber. The mechanical mixing method was identified as the most versatile preparation method in the review, but it is susceptible to causing agglomeration of nanomaterials. Furthermore, different vulcanization systems and reinforcing fillers can be chosen based on the application direction of FKM. Carbon nanomaterials with high inherent strength have the best reinforcing effect on FKM, although they also exhibit the most significant self-agglomeration effect. This can be mitigated through synergistic use of fillers of multiple dimensions and interfacial modification in future research. Additionally, current challenges and future prospects for FKM nanocomposites are also discussed.

Abstract The commercialization of Li−S batteries is seriously hindered by polysulfides with severe shuttle effect, and the inherent insulating properties and slow reaction kinetics of insoluble Li2S products. Transition metal sulfides (TMSs) have a high adsorption capacity for polysulfides and have been shown to have a strong catalytic effect on polysulfide conversion reactions. This paper reviews the research on the application of Unary TMSs, heterostructures, etc. in Li−S batteries, and gives some research methods for TMD catalysts in Li−S batteries. Finally, it points out the main focuses and direction of future Li−S battery research and development. It aims to provide some insights into the design and manufacture of advanced Li−S batteries for commercial use.

Abstract Sustainability and adaptability in structural design of the organic cathodes present promises for applications in alkali metal ion batteries. Nevertheless, a formidable challenge lies in their high solubility in organic electrolytes, particularly for small molecular materials, impeding cycling stability and high capacity. This study focuses on the design and synthesis of organic small molecules, the isomers of (E)‐5,5′‐difluoro‐[3,3′‐biindolinylidene]‐2,2′‐dione (EFID) and 3,9‐difluoro‐6,12‐dihydrodibenzo [c, h][2,6]naphthyridine‐5,11‐dione (FBND). While EFID, characterized by a less π‐conjugated structure, exhibits subpar cycling stability in lithium‐ion batteries (LIBs), intriguingly, another isomer, FBND, demonstrates exceptional capacity and cycling stability in LIBs. FBND delivers a remarkable capacity of 175 mAh g−1 at a current density of 0.05 A g−1 and maintains excellent cycling stability over 2000 cycles, retaining 90% of its initial capacity. Furthermore, an in‐depth examination of redox reactions and storage mechanisms of FBND are conducted. The potential of FBND is also explored as an anode in lithium‐ion batteries (LIBs) and as a cathode in sodium‐ion batteries (SIBs). The FBND framework, featuring extended π‐conjugated molecules with an imide structure compared to EFID, proves to be an excellent material template to develop advanced organic small molecular cathode materials for sustainable batteries.

Abstract MXenes are mentioned in many applications due to their unique properties. However, the traditional etching method has a lengthy synthesis time, dangerous process, and high cost. Molten salt etching is not only short in time but also safe and simple, laying a good foundation for industrialization. Here, we compare the traditional F‐containing etching method with the molten salt etching method. Transmission electron microscopy elemental mapping images and X‐ray photoelectron spectroscopy show that the Ti3C2Tx surface end of traditional etching is terminated by –F, while the Ti3C2Tx surface end of molten salt etching is terminated by –Cl. Finally, the sodium‐ion batteries are fabricated and the performance difference of the three etching methods is compared. The results show that the capacity of 102.1 mAh g–1 can still be reached when the molten salt etching MXene material returns to 0.1 A g–1 after the current density of 5 A g–1. After 500 cycles at 1 A g–1, there is no significant loss of capacity and the Coulomb efficiency is close to 100%. This work describes that molten salt etching MXene has comparable sodium storage capacity to conventional F‐containing etched MXene, making it a potential candidate for the production of large‐scale sodium‐ion batteries.

Abstract Hollow structuring has been identified as an effective strategy to enhance the cycling stability of electrodes for rechargeable batteries due to the outstanding volume expansion buffering efficiency, which motivates ardent pursuing on the synthetic approaches of hollow materials. Herein, an intriguing route, combining solid precursor transition and Ostwald ripening (SPTOR), is developed to craft nano single‐crystal (SC)‐constructed MnCO3 submicron hollow spindles homogeneously encapsulated in a reduced graphene oxide matrix (MnCO3 SMHSs/rGO). It is noteworthy that the H‐bonding interaction between Mn3O4 nanoparticles (NPs) and oxygen‐containing groups on GO promotes uniform anchoring of Mn3O4 NPs on GO, mild reductant ascorbic acid triggers the progressive solid‐to‐solid transition from Mn3O4 NPs to MnCO3 submicron solid spindles (SMSSs) in situ on GO, and the Ostwald ripening process induces the gradual dissolution of interior polycrystals of MnCO3 SMSSs and subsequent recrystallization on surface SCs of MnCO3 SMHSs. Remarkably, MnCO3 SMHSs/rGO delivers a 500th lithium storage capacity of 2023 mAh g−1 at 1000 mA g−1, which is 10 times higher than that of MnCO3 microspheres/rGO fabricated from a conventional Mn2+ salt precursor (202 mAh g−1). The ultrahigh capacity and ultralong lifespan of MnCO3 SMHSs/rGO can be primarily attributed to the superior reaction kinetics and reversibility combined with exceptional interfacial and capacitive lithium storage capability, enabled by the fast ion/electron transfer, large specific surface area, and robust electrode pulverization inhibition efficacy. Moreover, fascinating in‐depth lithium storage reactions of MnCO3 are observed such as the oxidation of Mn2+ in MnCO3 to Mn3+ in charge process after long‐term cycles and the further lithiation of Li2CO3 in discharge process. As such, the SPTOR approach may represent a viable strategy for crafting various hollow functional materials with metastable nanomaterials as precursors.

Abstract A simple method was proposed to activate alkaline Cu(OH)2 with an acidic ionomer, Nafion, to regulate its surface microenvironment, including hydrophobicity and local basicity. In particular, the direct complete neutralization reaction between Cu(OH)2 and Nafion in aqueous solution induces the exposing of vast anions which can exclude the in‐situ‐formed hydroxides and raise the local basicity. Remarkably, the optimal Nafion‐activated Cu(OH)2‐derived Cu can efficiently suppress the hydrogen evolution reaction (HER) and improve the selectivity for multi‐carbon products in the CO2 electroreduction reaction (eCO2RR). The H2 Faradaic efficiency (FE) decreased to 11% at a current density of 300 mA/cm2 (−0.76 V vs. RHE) in a flow cell, while the bare one with H2 had an FE of 40%. The total eCO2RR FE reaches as high as 83%, along with an evidently increased C2H4 FE of 44% as compared with the bare one (24%), and good stability (8000 s), surpassing that of most of the reported Cu(OH)2‐derived Cu. The experimental and theoretical results both show that the strong hydrophobicity and high local basicity jointly boosted the eCO2RR as acquired by felicitously introducing ionomer on the Cu(OH)2‐derived Cu surface.

Abstract The persistent increase of CO2 levels in the atmosphere, already exceeding 400 ppm, urges the exploration of CO2 emission reduction and recycling technologies. Ideally, photocatalytic conversion of CO2 into valuable hydrocarbons realizes solar‐to‐chemical energy conversion, which is a desirable “kill two birds with one stone” strategy; namely, CO2 photoreduction can simultaneously tackle energy shortage and keep global carbon balance. Graphitic carbon nitride (g‐C3N4) working on CO2 reduction reaction deserves a highlight not only for the metal‐free feature that endows it with low cost, tunable electronic structure, and easy fabrication properties but also because of its strong reduction ability. The present review concisely summarizes the latest advances of g‐C3N4‐based photocatalysts toward CO2 reduction. It starts with the discussion of thermodynamics and dynamics aspects of the CO2 reduction process. Then the modification strategies to promote g‐C3N4‐based photocatalysts in CO2 photoreduction have been discussed in detail, including surface functionalization, molecule structure engineering, crystallization, morphology engineering, loading cocatalyst, and constructing heterojunction. Meanwhile, the intrinsic factors affecting CO2 reduction activity and selectivity are analyzed and summarized. In the end, the challenges and prospects for the future development of highly g‐C3N4‐based photocatalysts in CO2 reduction are also presented.

Abstract A disubstituted quaterpyridine based cobalt complex non‐covalently tethered to multiwalled carbon nanotube (MWCNT) substrate, forming a hybrid catalyst, Co‐qpyCOOH/CNT, catalyzed the conversion of CO2 to CO under aqueous conditions. At an optimal and uniform loading, it exhibited remarkable catalytic activity, near‐exclusive selectivity, and high stability towards the formation of CO. At a mere cathodic potential of −0.65 V versus RHE (η = 0.54 V), it achieved a high partial current density of −6.7 mA/cm2 and a F.E.CO = 100%. In addition, with 20 h of stable operation, hydrogen evolution remained practically undetected. Its hybrid structure due to noncovalent immobilization on MWCNT imparted the intrinsic activity and much‐needed stability in performance whereas ‒COOH groups may stabilize the intermediates by acting as H‐bond donors, promoting catalytic activity. Tethering to a conductive solid substrate and tuning of the second sphere of coordination played an important role in its performance to achieve desired reduction product with high selectivity and activity.

Electrochemical degradation is the most critical challenge for Li-rich materials. Here, the authors reveal that manganese related phase reaction inhomogeneity coupling with transition metal rearrangement triggers electrochemical degradation in lithium-rich layered cathode.

An overview of recent developments of flame-retardant nylon 6 and nylon 66 is presented in this paper. The research of flame-retardant composites is mainly through adding flame-retardant elements to nylon molecules, which can be divided into physical addition and chemical addition. Each of these two methods has its advantages and disadvantages. In this paper, according to the different addition methods and flame-retardant mechanism of various flame-retardants, the flame-retardant properties of phosphorus flame-retardants, nitrogen flame-retardants, bio based flame-retardants and synergistic systems, as well as their effects on the mechanical properties of flame-retardant composites have been critically reviewed and summarized. This review will objectively explore and give new direction for the development of the flame-retardant nylon materials, which would be more accessible to the emerging field of materials science.

To improve the toughness and heat resistance of polylactic acid (PLA), polybutylene succinate (PBS) was sufficiently blended with PLA as the base matrix, and the glass fiber (GF) that was modified with 3-aminopropyltriethoxysilane (KF-GF) was added as the reinforcement. The results demonstrated a noteworthy boost in both mechanical and heat resistance properties when employing KH-GF, in comparison to pristine GF. When the content of KH-GF reached 20%, the tensile, flexural, and IZOD impact strength of the composites were 65.53 MPa, 83.43 MPa, and 7.45 kJ/m2, respectively, which were improved by 123%, 107%, and 189% compared to the base matrix, respectively. This enhancement was primarily attributed to the stronger interfacial adhesion between KH-GF and the PLA/PBS matrix. Furthermore, the Vicat softening temperature of the composites reached 128.7 °C, which was a result of increased crystallinity. In summary, the incorporation of KH-GF into PLA/PBS composites resulted in notable enhancements in their mechanical properties, crystallinity, and thermal characteristics. The high performance KH-GF-reinforced PLA/PBS composite showed a broad application potential in the field of biodegradable packaging, biodegradable textiles, and biodegradable plastic bags.

Nickel, cobalt, and manganese oxides are easily obtainable non-noble metal catalysts for water splitting. However, the relationship between composition and catalysts’ performance still needs systematic studies. Herein, guided by theoretical calculations, a low overpotential, easily prepared Mn-doped Co3O4 was deposited on graphite plates for water splitting. The 30% Mn-doped Co3O4 (Co2.1Mn0.9O4) required the lowest overpotential for oxygen evolution reaction (OER), in which the Co2.1Mn0.9O4 reached 20, 30, and 50 mA cm−2 in the overpotentials of 425, 451, and 487 mV, respectively, with 90% IR compensation. Under overall water-splitting conditions, the current density reached 30 mA cm−2 at an overpotential of 0.78 V without IR compensation. Charge density difference analysis illustrates that doped Mn provides electrons for O atoms, and that Mn doping also promotes the electron fluctuation of Co atoms. XPS analysis reveals that Mn-doping increases the chemical valence of the Co atom, and that the doped Mn atom also exhibits higher chemical valence than the Mn of Mn3O4, which is advantageous to boost the form of based-OOH* radical, then decrease the overpotential. Considering the particular simplicity of growing the Co2.1Mn0.9O4 on graphite plates, this work is expected to provide a feasible way to develop the high-performance Co-Mn bimetallic oxide for water splitting.

To manipulate the mechanical properties of fluororubber (FKM) composites, aminated multi-walled carbon nanotubes (MWCNT-A) and reduced graphene oxide (RGO) were introduced to synergistically create additional crosslinking between the FKM networks. Effects of the improved crosslinking on the mechanical, electrical and thermal properties of the FKM composites were systematically investigated in this research. The results showed that additional linkages were created due to the interactions between FKM and MWCNT-A and between MWCNT-A and RGO, resulting the thus-prepared FKM/MWCNT-A/RGO composites with excellent mechanical, electrical and thermal properties. Compared with the pristine FKM composite, the tensile strength, modulus at 100% strain, hardness, thermal and electrical conductivity of the FKM/MWCNT-A/RGO composite exhibited great increment of 43.8%, 656.3%, 34.5%, 30.3% and eight orders of magnitude, respectively. This research demonstrates that the construction of additional crosslinking with nanofillers represents an effective and promising route for a more broad range of industrial applications of FKM.

Abstract We report the synthesis of a high‐performance graphitic carbon‐coated silicon (Si@GC) composite material for lithium‐ion batteries via a scalable production route. Porous Si is produced from the magnesiothermic reduction of commercial silica (SiO2) precursor followed by low‐temperature graphitic carbon coating using glucose as the precursor. The obtained Si@GC composite achieves an excellent reversible specific capacity of 1195 mAh g−1 and outstanding cycle stability. The thick Si@GC anode (3.4 mg cm−2) in full cells with commercial lithium iron phosphate cathode delivers a remarkable performance of 800 mAh g−1 specific capacity and 2.7 mAh cm−2 areal capacity as well as 93.6% capacity retention after 200 cycles.

To improve the properties of fluororubber (FKM), aminated carbon nanotubes (CNTs-NH2) and acidified carbon nanotubes (CNTs-COOH) were introduced to modulate the interfacial interactions in FKM composites. The effects of chemical binding and F–H polar interactions between CNTs-NH2, CNTs-COOH, and FKM on the mechanical, electrical, thermal, and wear properties of the FKM composites were systematically investigated. Compared to the pristine FKM, the tensile strength, modulus at 100% strain, hardness, thermal conductivity, carbon residue rate, and electrical conductivity of CNTs-NH2/CNTs-COOH/FKM were increased by 112.2%, 587.5%, 44.2%, 37.0%, 293.5%, and nine orders of magnitude, respectively. In addition, the wear volume of CNTs-NH2/CNTs-COOH/FKM was reduced by 29.9%. This method provides a new and effective way to develop and design high-performance fluororubber composites.

Manganese dioxide is regarded as a promising energy functional material due to its open tunnel structure with enormous applications in energy storage and catalysis. In this paper, α-MnO2 with a 2 × 2 tunnel structure and β-MnO2 with a 1 × 1 tunnel structure were hydrothermally synthesized, which possess characteristic tunnel structures formed by the interconnected unit structure of [MnO6] octahedrons. With regards to their different tunnel dimensions, the specific mechanism of ion intercalation in these two phases and the effect on their performance as aqueous Zn-MnO2 battery cathodes are explored and compared. Comprehensive analyses illustrate that both α-MnO2 and β-MnO2 provide decent capacity in the aqueous battery system, but their intrinsic stability is poor due to the structural instability upon cycling. At the same time, experiments show that α-MnO2 has a better rate performance than β-MnO2 under larger currents, thus implying that the former has a broader application in this aqueous battery system.

Summary: Sodium-ion batteries are emerging energy storage and conversion devices for a sustainable and clean society. The performance of sodium-ion batteries can be reasonably boosted through structural engineering of electrode materials. Herein, different structural engineering strategies for typical electrode materials are clearly classified and introduced. For different types of electrode materials, emphasis is put on structural design and/or modification, both of which are presented in detail. The roles and effects of effective strategies are systematically summarized and prospected at the end. It is expected to provide a whole picture and insight into the structural design and modification of various electrode materials for sodium-ion batteries that can be extended to other metal-ion batteries.

Abstract The oxygen evolution reaction (OER) is pivotally involved in proton exchange membrane water electrolyzers (PEMWEs). However, the commercialized iridium‐based catalysts often suffer from severe sluggish kinetics, eventually deteriorating the polarization and overall PEMWEs performance. Therefore, to develop OER electrocatalysts with promising reaction kinetics and high stability is of great significance for PEMWEs. Compared to iridium, the ruthenium‐based catalysts possess lower price and higher activity in acidic water oxidation, which promises Ru‐based materials to replace the state‐of‐the‐art IrOx. Yet, the less stable ruthenium than iridium impedes its real applications. In this mini review, recent knowledge of feasible engineering strategies for migrating the Ru‐based electrocatalysts' stability is summarized. In order to improve performance and durability, basic fundamentals of acidic OER on nanoscale and molecular engineered Ru‐based electrocatalysts are briefly introduced. In the end, the challenges and outlook for engineering novel Ru‐based electrocatalysts are presented.

In this paper, to enhance the toughness and heat resistance properties of polylactic acid (PLA)/polybutylene succinate (PBS) composites, the PLA/PBS matrix was modified by different glass fiber (GF), GF/SiO2, and GF/(Polyaluminium chloride) PAC fillers. Additionally, the effect of filler type, filler content, components interaction and composite structure on the mechanical and thermal properties of the PLA/PBS composites was researched. The results showed that the addition of GF, GF/SiO2 and GF/PAC make the PLA/PBS composites appear significantly higher mechanical properties compared with the pristine PLA/PBS composite. Among the different inorganic fillers, the 10%GF/1%SiO2 fillers showed excellent strengthening, toughening and heat resistant effects. Compared with the pristine PLA/PBS matrix, the tensile strength, elastic modulus, flexural strength, flexural modulus and Izod impact strength improved by 36.28%, 70.74%, 67.95%, 66.61% and 135.68%, respectively. Considering the above, when the weight loss rate was 50%, the thermal decomposition temperature of the 10%GF/1%SiO2 modified PLA/PBS composites was the highest 412.83 °C and its Vicat softening point was up to 116.8 °C. In a word, the 10%GF/1%SiO2 reinforced PLA/PBS composites exhibit excellent mechanical and thermal properties, which broadens the application of biodegradable materials in specific scenarios.

This study is dedicated to expand the family of lithium-tellurium sulfide batteries, which have been recognized as a promising choice for future energy storage systems. Herein, a novel electrochemical method has been applied to engineer micro-nano TexSy material, and it is found that TexSy phases combined with multi-walled carbon nanotubes endow the as-constructed lithium-ion batteries excellent cycling stability and high rate performance. In the process of material synthesis, the sulfur was successfully embedded into the tellurium matrix, which improved the overall capacity performance. TexSy was characterized and verified as a micro-nano-structured material with less Te and more S. Compared with the original pure Te particles, the capacity is greatly improved, and the volume expansion change is effectively inhibited. After the assembly of Li-TexSy battery, the stable electrical contact and rapid transport capacity of lithium ions, as well as significant electrochemical performance are verified.

Though solar cells are one of the promising technologies to address the energy crisis, this technology is still far from commercialization. Thermoelectric materials offer a novel opportunity to convert energy between thermal and electrical aspects, which show the feasibility to improve the performance of solar cells via heat management and light harvesting. Polymer–inorganic thermoelectric nanocomposites consisting of inorganic nanomaterials and functional organic polymers represent one kind of advanced hybrid nanomaterials with tunable optical and electrical characteristics and fascinating interfacial and surface chemistry. During the past decades, they have attracted extensive research interest due to their diverse composition, easy synthesis, and large surface area. Such advanced nanomaterials not only inherit low thermal conductivity from polymers and high Seebeck coefficient, and high electrical conductivity from inorganic materials, but also benefit from the additional interface between each component. In this review, we provide an overview of interfacial chemistry engineering and electrical feature of various polymer–inorganic thermoelectric hybrid nanomaterials, including synthetic methods, properties, and applications in thermoelectric devices. In addition, the prospect and challenges of polymer–inorganic nanocomposites are discussed in the field of thermoelectric energy.

Summary: Metal organic framework (MOF) derivatives have been extensively used as bifunctional oxygen electrocatalysts. However, the utilization of active sites is still not satisfactory owing to the sluggish mass transport within their narrow pore channels. Herein, interconnected macroporous channels were constructed inside MOFs-derived Co-Nx-C electrocatalyst to unblock the mass transfer barrier. The as-synthesized electrocatalyst exhibits a honeycomb-like morphology with highly exposed Co-Nx-C active sites on carbon frame. Owing to the interconnected ordered macropores throughout the electrocatalyst, these active sites can smoothly “exhale/inhale” reactants and products, enhancing the accessibility of active sites and the reaction kinetics. As a result, the honeycomb-like Co-Nx-C displayed a potential difference of 0.773 V between the oxygen evolution reaction potential at 10 mA cm−2 and the oxygen reduction reaction half-wave potential, much lower than that of bulk-Co-Nx-C (0.842 V). The rational modification on porosity makes such honeycomb-like MOF derivative an excellent bifunctional oxygen electrocatalyst in rechargeable Zn-air batteries.

Compared with traditional lithium-ion systems, solid-state batteries could achieve high safety and energy density. Although great improvements have been made, especially in solid-state electrolytes, fundamental challenges still remain for the solid-state systems in terms of chemistry and mechanics. This review summarizes the fundamental issues in solid-state batteries with a focus on three critical phenomena: (i) the principles of developing high ionic conductors, (ii) structural evolution at chemically unstable electrolyte-electrode interfaces, and (iii) the effects of manufacturing solid-state batteries, including electrode, and electrolyte design. The future perspectives are also outlined to guide the development of solid-state batteries.

Nanofiltration membranes are important for water desalination technologies, but designing membranes that achieve both high permeance and high salt rejection remains challenging. Here, the authors use sacrificial nanoparticles in the membrane fabrication process, leading to crumpled structures with ultrahigh permeance.