ATP-binding cassette (ABC) transporters, a large class of transmembrane proteins, are widely found in organisms and play an important role in the transport of xenobiotics. Insect ABC transporters are ...involved in insecticide detoxification and
(Bt) toxin perforation. The complete ABC transporter is composed of two hydrophobic transmembrane domains (TMDs) and two nucleotide binding domains (NBDs). Conformational changes that are needed for their action are mediated by ATP hydrolysis. According to the similarity among their sequences and organization of conserved ATP-binding cassette domains, insect ABC transporters have been divided into eight subfamilies (ABCA-ABCH). This review describes the functions and mechanisms of ABC transporters in insecticide detoxification, plant toxic secondary metabolites transport and insecticidal activity of Bt toxin. With improved understanding of the role and mechanisms of ABC transporter in resistance to insecticides and Bt toxins, we can identify valuable target sites for developing new strategies to control pests and manage resistance and achieve green pest control.
Currently, emerging battery technologies are being studied intensively. The lack of ideal electrode materials remains a key hindrance to further development of new batteries. The novel MXene ...material, due to its unique structural characteristics and physicochemical properties, shows the ability to enhance the electrochemical performance of the electrode. In addition to the adjustable layer spacing, because of excellent electrical conductivity, rich chemical composition, and controllable surface chemistry, MXene has the potential for use in diverse applications as an ideal electrode material in various battery systems. This review covers the recent progress achieved in research of the zinc‐ion energy storage of MXenes, including MXene‐based cathodes, MXene‐derived cathodes, MXene‐modified zinc anodes, and electrolyte additives. Moreover, further structural design and reaction mechanisms of MXenes in zinc‐ion storage are explored.
MXenes, as emerging two‐dimensional (2D) materials with unique structural characteristics and physical and chemical properties, have been successfully applied in zinc‐ion energy storage to improve the electrochemical performance of the electrode. In this review, the authors summarize the recent advances of research on 2D MXenes for zinc‐ion energy storage and further discuss the structural design and reaction mechanisms of MXenes. This review provides valuable insights into the challenges in the use of MXenes in zinc‐ion energy storage and aims to study practical applications of zinc‐ion energy storage.
► A novel EG-RGO/PPy composite for supercapacitor application is well constructed. ► The well-soluble GO was dispersed in aqueous polymerisable aniline monomer solution to form stable GO/PPy ...structure. ► The EG reduced RGO/PPy can retain the PPy conductive conjugative frameworks. ► The EG-RGO/PPy electrode exhibits superior electrochemical capability as supercapacitor electrode.
A promising supercapacitor material based on graphene/polypyrrole (PPy) has been successfully synthesized via in situ oxidation polymerization of pyrrole monomers in aqueous graphene oxide (GO) solutions, followed by chemical reduction using ethylene glycol (EG). Unlike the commonly employed hydrazine reduction, the moderate EG reductant does not destruct the PPy conjugative structures, thus facilitating utilization of the electroactive conductive polymer. The morphologies and the structures of the as-prepared materials are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectra, and Fourier transform infrared spectroscopy (FTIR). And the electrochemical performance of the fabricated electrodes was evaluated by cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). The EG-RGO/PPy electrode shows large specific capacitance, high rate performance, and good charge–discharge stability as well. The excellent electrochemical capability is mainly accounted for the sound composite construction that improves the effective utilization of electroactive PPy component, accelerates shuttling the charged carriers, and alleviates the swelling/shrinkage of polymer chains.
Sodium‐ion batteries (SIBs), which are an alternative to lithium‐ion batteries (LIBs), have attracted increasing attention due to their low cost of Na resources and similar Na storage mechanism to ...LIBs. Compared with anode materials and electrolytes, the development of cathode materials lags behind. Therefore, the key to improving the specific energy and promoting the application of SIBs is to develop high‐performance sodium intercalation cathode materials. Transition‐metal oxides are one of the most promising cathode materials for SIBs owing to their excellent energy density, high specific discharge capacity, and environmentally friendly nature. In the present work, the latest progress in the research of transition‐metal oxides is summarized. Moreover, the existing challenges are discussed, and a series of strategies are proposed to overcome these drawbacks. This review aims at providing guidance for the development of metal oxides in the next stage.
Transition‐metal oxide is one of the most promising cathode materials in sodium‐ion batteries. In this review, Tao Chen, Baixue Ouyang et al. review the method of transition‐metal ion doping and their effects on the electrode's performance. Current challenges and further research directions in this field are also summed up.
In this paper, we first investigate the existence of a periodic solution to interval general bidirectional associative memory (BAM) neural networks with multiple delays on time scales by the ...continuation theorem of coincidence degree theory. Then, by constructing a Lyapunov functional, we discuss the global exponential stability of the periodic solution for such neural networks on time scales. The paper unifies periodic discrete-time and continuous-time BAM neural networks under the same framework.
This paper introduces a new design route to fabricate nickel aluminum-layered double hydroxide (NiAl-LDH) nanosheets/hollow carbon nanofibers (CNFs) composite through an in situ growth method. The ...NiAl-LDH thin layers which grow on hollow carbon nanofibers have an average thickness of 13.6 nm. The galvanostatic charge–discharge test of the NiAl-LDH/CNFs composite yields an impressive specific capacitance of 1613 F g−1 at 1 A g−1 in 6 M KOH solution, the composite shows a remarkable specific capacitance of 1110 F g−1 even at a high current density of 10 A g−1. Furthermore, the composite remains a specific capacitance of 1406 F g−1 after 1000 cycles at 2 A g−1, indicating the composite has excellent high-current capacitive behavior and good cycle stability in compared to pristine NiAl-LDH.
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•Nickel aluminum-LDH grown on hollow carbon nanofibers by an in situ growth method.•NiAl-LDH/CNFs composite presents as three-dimensional network structure.•The composite exhibited a high specific capacitance of 1613 F g−1 at 1 A g−1.•Remarkable cycle performance at a current density of 2 A g−1.
We report a Ni-Al layered double hydroxide (LDH)-graphene superlattice composite via alternating assembly of the exfoliated thin flakes with opposite charges that show stable high-rate performance ...for alkaline battery cathodes.
MXene is widely used as electrode materials in lithium-ion batteries due to its unique morphology, which realizes rapid ion diffusion and provides more ion insertion channels, whereas transition ...metal phosphides show a promising lithium storage performance in the field of energy storage due to their high theoretical capacity. In the present paper, cobalt phosphide nanoparticles (NPs) were self-grown on Ti3C2 sheets via a low-temperature phosphating method, which showed good cycle stability as the anode in lithium-ion batteries (LIBs). After 1000 cycles, the specific capacity was maintained at 650 mAh g−1 with a high coulombic efficiency (98.8%) at 700 mA g−1, which was approximately 4 and 6 times higher than that of pristine CoP–Co2P and pure Ti3C2, respectively. The enhanced electrochemical performance was attributed to the large specific surface (61.2 m2 g−1), which offered sufficient active sites for the electrochemical reaction. Also, the outstanding redox reaction activity of cobalt phosphide effectively improved the electrochemical reaction efficiency during the charge-discharge process. The strategy proposed in this study could be extended to other two dimensional (2D) materials to achieve their full potential.
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•CoP–Co2P are self-grown on Ti3C2 via a low-temperature phosphorization method.•CoP–Co2P were uniformly distributed among interlamination spaces of Ti3C2 sheet.•CoP–Co2P/Ti3C2 shows excellent lithium storage performance and reversibility.•The electrochemical reaction mechanism of CoP–Co2P/Ti3C2 was discussed in detail.•The strategy can be extended to other 2D materials to achieve their potential.
Silicon‐based (Si) materials are promising anodes for lithium‐ion batteries (LIBs) because of their ultrahigh theoretical capacity of 4200 mA h g−1. However, commercial applications of Si anodes have ...been hindered by their drastic volume variation (∼300%) and low electrical conductivity. Here, to tackle the drawbacks, a hierarchical Si anode with double‐layer coatings of a SiOx inner layer and a nitrogen (N), boron (B) co‐doped carbon (C–NB) outer layer is elaborately designed by copyrolysis of Si–OH structures and a H3BO3‐doped polyaniline polymer on the Si surface. Compared with the pristine Si anodes (7 mA h g−1 at 0.5 A g−1 after 340 cycles and 340 mA h g−1 at 5 A g−1), the modified Si‐based materials (Si@SiOx@C–NB nanospheres) present superior cycling stability (reversible 1301 mA h g−1 at 0.5 A g−1 after 340 cycles) as well as excellent rate capability (690 mA h g−1 at 5 A g−1) when used as anodes in LIBs. The unique double‐layer coating structure, in which the inner amorphous SiOx layer acts as a buffer matrix and the outer defect‐rich carbon enhances the electron diffusion of the whole anode, makes it possible to deliver excellent electrochemical properties. These results indicate that our double‐layer coating strategy is a promising approach not only for the development of sustainable Si anodes but also for the design of multielement‐doped carbon nanomaterials.
The mechanism illustration about the preparation of Si@SiOx@C–NB materials.
Highlights
Double‐layer coatings are generated on the surface of Si nanoparticles via the pyrolysis of surficial Si‐OH structures and PANI–H3BO3 precoatings.
The amorphous SiOx inner‐layer can effectively promote the wettability of Si anodes with electrolyte and the combination between Si particles and the binder.
The N,B co‐doped carbon outer‐layer shows a defect‐rich nature and can enhance the conductivity of the whole Si anode.
The Si@SiOx@C–NB anode exhibits excellent rate capability and cycling stability.
Highly ordered TiO2 nanotube arrays (NTAs) with excellent stability and large specific surface area make them competitive using as supercapacitor materials. Improving the conductivity of TiO2 is of ...great concern for the construction of high-performance supercapacitors. In this work, we developed a novel approach to improve the performance of TiO2 materials, involving the fabrication of Al-doped TiO2 NTAs by a simple electrochemical cathodic polarization treatment in AlCl3 aqueous solution. The prepared Al-doped TiO2 NTAs exhibited excellent electrochemical performances, attributing to the remarkably improved electrical conductivity (i.e., from approx. 10 kΩ to 20 Ω). Further analysis showed that Al3+ ions rather than H+ protons doped into TiO2 lattice cause this high conductivity. A MnO2/Al–TiO2 composite was evaluated by cyclic voltammetry, and achieved the specific capacitance of 544 F g−1, and the Ragone plot of the sample showed a high power density but less reduction of energy density. These results indicate that the MnO2/Al–TiO2 NTAs sample could be served as a promising electrode material for high -performance supercapacitors.
•we report a mild electrochemical method to form Al-doped TiO2 nanotube arrays (NTAs).•Al-doped TiO2 NTAs show a highest electrical conductivity of approx. 20 Ω.•The elemental composition of Al-doped TiO2 NTAs were studied by XPS analysis.•Al-doped TiO2 were proved to be excellent supports materials for supercapacitors.
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