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•A molecular scissor was invented to engineer the surface of carbon nanomaterials.•It is an efficient and ubiquitous method to rationally modulate pre-existing carbon nanomaterials of ...different forms .•A tailored tubular superstructured nanocarbon supercapacitor was fabricated and outperformed most existing carbon supercapacitors.
Carbon is a fascinating element that can be found in a wide spectrum of materials and plays a significant role in diverse disciplines across the scientific community. Carbon nanomaterials take many forms with numerous applications. Controllably tailoring carbon nanomaterials at the molecular scale can be considered as a basic innovation yet remains a significant challenge because of carbon’s intrinsic structural and chemical stability. Herein, we report a molecular scissor to efficiently tailor carbon nanomaterials of different dimensions at a molecular level. By using the Mg/Zn bimetallic effect and CO2 molecules, a molecular scissor was invented to engineer the surface of carbon nanomaterials with highly interconnected graphene pillared superstructures. The molecular scissor redesigned the carbon materials with improved surface properties for use in various applications. For energy storage application, both ultrahigh surface area and conductivity can be achieved concurrently with substantial ion-reserved accommodation and rapid mass-transfer expressway. As a demonstration, a flexible solid-state supercapacitor based on the surface-tailored carbon fiber was developed with Polyvinyl alcohol(PVA)/Na2SO4 gel electrolytes. It delivered a remarkably high energy density of 4.63 mW h cm–3 at a power density of 3520 mW cm–3. This work paves a new way to reinvent carbon materials at the molecular scale and promote their applications for energy storage, sensing, environmental remediation, and healthcare.
The O-N-S co-doped hierarchical porous carbons are prepared by direct pyrolysis of kraft lignin which is the byproduct from papermaking black liquor. The proposed preparation method is extremely ...facile, green-environmental, and low-cost without any additional activating agents, additives or templates. The kraft lignin-derived carbon materials possess large specific surface areas (338−1307 m2 g−1), hierarchical porous structures and abundant multi-heteroatoms co-doping (9.84–19.91 wt%). Benefiting from above synergistic advantages, the as-fabricated symmetric supercapacitor in aqueous electrolyte delivers a high specific capacitance of 244.5 F g−1 at 0.2 A g−1, excellent rate-capability (81.8% retention of initial capacitance at 40.0 A g−1), and outstanding cycling stability (91.6% retention over 10000 cycles). Importantly, this device in aqueous electrolyte delivers an energy density of 8.5 W h kg−1 at a power density of 100 W kg−1. Furthermore, a remarkable energy density of 66.8 W h kg−1 at a power density of 1.75 kW kg−1 has been achieved and 32.2 W h kg−1 is still maintained even at an ultrahigh power density of 40.0 kW kg−1 when ionic liquid serves as electrolyte. This study demonstrates the successful conversion of low-valued natural biomass derivative into sustainable high-performance supercapacitor electrode materials with a simple, low-cost, and green-environmental production process.
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The yield of the quaternary nitrogen-containing Ti3AlCN ceramics was evidently proved to be up to 70% by the controllable AlN-oversaturation precursor strategy. Such relatively high-yield quaternary ...Ti3AlCN is mainly ascribed to the elimination of Al segregation.
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Ti3CNTx MXenes with unique electrical conductivity can be widely applied for supercapacitors and electromagnetic shielding. However, its relatively low-yield quaternary nitrogen-containing Ti3AlCN ceramics precursor (less than 50%), due to the inevitable Al segregation during the synthesizing process, significantly hindered its widely commercial applications. Herein, we employed the controllable AlN-oversaturation precursor strategy to precisely tune the phase transition point of quaternary Ti3AlCN ceramics to obtain high-yield Ti3AlCN precursor for the purpose of high conductivity Ti3CNTx MXenes. Combined energy dispersive X-ray spectrometer (XRD) with X-ray photoelectron spectroscopy (XPS) characterizations, the yield of the quaternary nitrogen-containing Ti3AlCN ceramics was evidently proved to be up to 70%, which is 1.4 times than that of previously reported works. Such relatively high-yield quaternary Ti3AlCN is mainly ascribed to the elimination of Al segregation. Based on it, we further developed accordion-like two-dimensional (2D) MXene via hydrofluoric acid etch and vacuum freeze-dry. This novel accordion-like 2D Ti3CNTx MXene possesses high electrochemical capacitive properties (209 F/g). Therefore, this controllable AlN-oversaturation precursor strategy will pave a way to exploit costly high-yield MAX ceramics precursor for high conductivity MXenes and also play a powerful role in promoting their practical applications including electrical and magnetic engineering fields.
An acceleration sensor is an essential component of the vibration measurement, while the passivity and sensitivity are the pivotal features for its application. Here, we report a self-powered and ...highly sensitive acceleration sensor based on a triboelectric nanogenerator composed of a liquid metal mercury droplet (LMMD) and nanofiber-networked polyvinylidene fluoride (nn-PVDF) film. Due to the ultrahigh surface-to-volume ratio of nn-PVDF film and high surface tension, high mass density, high elastic as well as mechanical robustness of LMMD, the open-circuit voltage and short-circuit current reach up to 15.5 V and 300 nA at the acceleration of 60 m/s2, respectively. The acceleration sensor has a wide detection range from 0 to 60 m/s2 with a high sensitivity of 0.26 V·s/m2. Also, the output voltage and current show a negligible decrease over 200,000 cycles, evidently presenting excellent stability. Moreover, a high-speed camera was employed to dynamically capture the motion state of the acceleration sensor for insight into the corresponding work mechanism. Finally, the acceleration sensor was demonstrated to measure the vibration of mechanical equipment and human motion in real time, which has potential applications in equipment vibration monitoring and troubleshooting.
Design and synthesis of high-efficiency multicomponent nanostructure for activating peroxymonosulfate (PMS) to destruct emerging antibiotics remains a daunting challenge. We report herein the ...simplest one-step hydrothermal construction of hierarchical Fe/Fe2O3@MoS2 architecture composed of MoS2 nanosheets integrated commercial Fe2O3 nanoparticles. The fabricated Fe/Fe2O3@MoS2 architecture can be utilized as an efficient PMS activator to destruct tetracycline hydrochloride (TCH) with a removal efficiency of 90.3 % within 40 min, outperforming Fe2O3 nanoparticles, MoS2 nanosheets analogues and many MoS2-based materials. The Fe/Fe2O3@MoS2/PMS works well under various reaction conditions, and SO4•− and 1O2 are identified as major reactive oxygen species. Thirteen intermediates towards TCH destruction are detected via four pathways, and their acute/chronic toxicity and phytotoxicity are assessed. The origins of Fe/Fe2O3@MoS2/PMS system for efficient degrading TCH are ascribed to the synergy catalysis between Fe2O3 and MoS2, which originate from: (a) the exposed Mo4+ sites on catalyst surface facilitating high-speed electron transfer from MoS2 to Fe3+ and accelerating the Fe2+ regeneration; (b) the generated Fe0 serving as an excellent electron donor to jointly promote Fe3+/Fe2+ redox cycle. This study provides a simple way to establish architecture for synergistically promoting PMS-mediated degradation.
•Fe/Fe2O3 integrated MoS2 architecture is obtained via a one-step hydrothermal method.•Synergy between Fe/Fe2O3 and MoS2 enhanced the catalytic activity for PMS activation.•Fe/Fe2O3@MoS2/PMS system involves multiple ROSs with SO4.•− and 1O2 as dominant species.•Toxicity of intermediates and degradation pathways by the system are unveiled.
As in the case of supercapacitors, spinel NiCo2O4 shows the main drawbacks of objectionable pseudocapacitive mechanism, low-voltage polarization effect and confined ion-reaction dynamics, which ...result in constrained development, narrow work voltage, and low loading mass. Herein we combined two strategies to address these issues. The first one is to design the flower-like NiCo2O4 through Ostwald ripening of ultrathin Ni-Co layered double-hydroxide petals. And the second one is to balance the asymmetrical capacitance for further promoting capacitive behavior. With rationally designing the nano-/micro-structures, flower-like NiCo2O4 shows highly porous ultrathin petals interconnected with each other and massive interspaces between the petals. This unique microstructure endows flower-like NiCo2O4 with rapid electrolyte ions diffusion and mass transfer reaction. Consequently, the flower-like NiCo2O4 electrodes exhibit a high capacity of ∼350 C g−1 even the loading mass of up to 9 mg cm−2. More importantly, the hybrid supercapacitors, assembled with flower-like NiCo2O4 as cathode, deliver a high specific capacity of ∼85 F g−1 with capacitive ratio up to 74.3%, and a high working voltage of 1.55 V. The transformation of conventional battery-like materials into novel capacitive dominated materials through nano/micro-structural design and balance of asymmetrical capacitance is helpful to further understand the pseudocapacitive mechanism of transition metal oxides/sulfides and therefore will promote their practical application in next-generation of hybrid supercapacitors.
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•RCSSs are rationally synthesized by in-situ conversion with ex-situ assembly method.•RCSSs exhibit excellent rate capability and cycle stability.•High-power density and high energy ...density are simultaneously achieved.
Rationally designing three-dimensional complex carbon superstructures for energy storage applications offers opportunities to tackle challenges driven by increasingly higher demand of portable energy devices. Herein we report in-situ controlled constructibility and ex-situ confined assembly strategies to enable novel raspberry-like carbon superstructures (RCSSs) for the enhancement of advanced supercapacitors. Through precise control of edge-to-surface ratio and optimization of inner pore structure, the resultant RCSSs show three-dimensional hierarchical porous framework, large specific surface area (SSA, ∼1000 m2 g−1) and high electrical conductivity (∼2700 S m−1), which facilitate ion diffusion and electron transfer. The predesigned RCSSs used as the electrode materials in symmetrical supercapacitors exhibit high rate capability, as indicated by 25,000% increment of the current density only leading to low capacitance degradation of 11.7%, and show long-term cycling stability (98.3% retention after 10,000 cycles) in 6 M KOH electrolyte. Moreover, the RCSSs simultaneously deliver high energy density of 46.5 Wh kg−1 and high power density of 52.5 kW kg−1 in ionic liquid electrolytes. We believe that the combination of in-situ and ex-situ approaches yielded carbon superstructures with complex microstructure and outstanding electrical properties show promising application for universally advanced energy devices with superior power and energy characteristics.
Solid-state composite polymer electrolytes (CPEs) usually suffer from intrinsic low ionic conductivity and a solid–solid interface, badly inhibiting their widespread commercial application in ...all-solid-state Li-metal battery (ASSLMB) energy storage. Herein, a synergetic strategy using strong Lewis acid–base and weak hydrogen bonds was employed for self-assembly in situ construction of three-dimensional (3D) network-structured poly(ethylene oxide) (PEO) and SiO2 CPEs (PEO@SiO2). Ascribed to this synergistically rigid–flexible coupling dynamic strategy, a harmonious incorporation of monodispersed SiO2 nanoparticles into PEO could remarkably reduce crystallinity of PEO, significantly enhancing the ionic conductivity (∼1.1 × 10–4 S cm–1 at 30 °C) and dramatically facilitating solid electrolyte interface stabilization (electrochemical stability window > 4.8 V at 90 °C). Moreover, the PEO@SiO2-based ASSLMBs possess excellent rate capability over a wide temperature range (∼105 mA h g–1 under 2 C at 90 °C), high temperature cycling capacity (retaining 90 mA h g–1 after 100 cycles at 90 °C), and high specific capacity (146 mA h g–1 under 0.3 C at 90 °C). Unambiguously, these high ionic conductivity CPEs along with excellent flexibility and safety can be one of the most promising candidates for high-performance ASSLMBs, evidently revealing that this synergistically rigid–flexible coupling dynamic strategy will open up a way to exploit the novel high ionic conductivity solid-state electrolytes.
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•HPSNCs were obtained by a simply large-scale preparing method.•Hierarchically porous structure from micro-to-macro-pores are obtained.•High power density along with high energy ...density are achieved.•The HPSNC-based EDLCs show superior cycling stability.
Supercapacitors with ionic liquid (IL) electrolytes can reach high work voltage and accompanied high energy density, which are the critical parameters for supercapacitors’ rapid development. However, supercapacitors with IL electrolytes usually suffer from low power density due to low conductivity, large ionic size and high viscosity of the electrolytes. Herein we reported hierarchically porous sheet-like nanocarbons (HPSNCs) prepared by direct activation of graphene oxide and polytetrafluoroethylene (PTFE) polymer are promising electrode materials for high power supercapacitors with also high energy density. During the activation process, the PTFE particles as a spacer that can effectively hinder the restack of graphene oxide and simultaneously transformed into sheet-like nanocarbons at high temperatures. As a result, the as-prepared samples exhibit highest surface area of∼2000m2g−1 and largest pore volume of 1.90cm3g−1. Benefit from hierarchically porous structure from micro-to-macro-pores, which largely shorten the diffusion distance of electrolyte ions, the HPSNC electrodes show a high energy density of 51.7Whkg−1 at a power density of 35kWkg−1 in symmetric supercapacitors with IL electrolyte. In addition, the HPSNC-based supercapacitors also possess an excellent cycling stability with 88% capacitance retention after 5000 cycles. Unambiguously, this work demonstrated the potential of HPSNCs for high power supercapacitors with high energy density and application in integrated energy management electronics.
Biomass-based energy storage devices have drawn increasing attention owing to their renewability and sustainability, particularly that the heteroatom-doped carbons derived from natural polymers are ...regarded as the promising candidates in discovering advanced electrode materials for supercapacitors. This work has developed a facile one-pot fabrication strategy toward synthetic pheomelanin nanoparticles with controllable size and chemical composition (i.e., sulfur content) via the copolymerization of dopamine and cysteine. The resulting synthetic pigment materials possess outstanding thermal stability and are able to directly transform into monodispersed S,N-codoped carbon spheres with unaltered morphology. Compared with conventional polydopamine-based carbon spheres, the present carbonized pheomelanin nanoparticles with electroactive sulfur atoms could possess lower charge-transfer resistance and consequently higher specific capacitance (e.g., 243 F g–1 at 1 A g–1). This research continues to inspire researchers to develop new kinds of energy storage materials based on synthetic biopigment materials.
