A hybrid chemically converted graphene nanosheet/Ni 2+ /Al 3+ layered double-hydroxide (GNS/LDH) composite for supercapacitor material has been fabricated by a hydrothermal method. Scanning electron microscopy and transmission electron microscopy results reveal that Ni 2+ /Al 3+ LDH platelets homogeneously grew onto the surfaces of the GNSs as spacers to keep the neighboring sheets separate. Electrochemical properties were characterized by cyclic voltammetry, galvanostatic charge/discharge measurements, and electrochemical impedance spectroscopy. The composite exhibits a maximum specific capacitance of 781.5 F/g and excellent cycle life with an increase of the specific capacitance of 38.07% after 50 cycle tests. Even after 200 cycle tests, the increase of the capacitance is 22.56% compared with the initial capacitance.
Multidrug resistance is a major challenge to cancer chemotherapy. The multidrug resistance phenotype is associated with the overexpression of the adenosine triphosphate (ATP)-driven transmembrane efflux pumps in cancer cells. Here, we report a lipid membrane-coated silica-carbon (LSC) hybrid nanoparticle that targets mitochondria through pyruvate, to specifically produce reactive oxygen species (ROS) in mitochondria under near-infrared (NIR) laser irradiation. The ROS can oxidize the NADH into NAD+ to reduce the amount of ATP available for the efflux pumps. The treatment with LSC nanoparticles and NIR laser irradiation also reduces the expression and increases the intracellular distribution of the efflux pumps. Consequently, multidrug-resistant cancer cells lose their multidrug resistance capability for at least 5 days, creating a therapeutic window for chemotherapy. Our in vivo data show that the drug-laden LSC nanoparticles in combination with NIR laser treatment can effectively inhibit the growth of multidrug-resistant tumors with no evident systemic toxicity.
Electrochemical energy storage devices, such as supercapacitors and batteries, have been proven to be the most effective energy conversion and storage technologies for practical application. However, further development of these energy storage devices is hindered by their poor electrode performance. Carbon materials used in supercapacitors and batteries are often derived from nonrenewable resources under harsh environments. Naturally abundant biomass is a green, alternative carbon source with many desired properties. This review article presents state of the art of renewable carbon materials derived from natural biomasses with an emphasis on their applications in supercapacitors and lithium-sulfur batteries.
IMPACT STATEMENTThis review paper provides a comprehensive understanding for obtaining renewable carbons from natural biomass precursors via various activation methods for electrochemical energy storage application, especially for supercapacitor and lithium sulfur battery.
ARTICLE HISTORY
A Ni-Al layered double hydroxide (LDH), mutil-wall carbon nanotube (CNT), and reduced graphene oxide sheet (GNS) ternary nanocomposite electrode material has been developed by a facile one-step ethanol solvothermal method. The obtained LDH/CNT/GNS composite displayed a three-dimensional (3D) architecture with flowerlike Ni-Al LDH/CNT nanocrystallites gradually self-assembled on GNS nanosheets. GNS was used as building blocks to construct 3D nanostructure, and the LDH/CNT nanoflowers in turn separated the two-dimensional (2D) GNS sheets, which preserved the high surface area of GNSs. Furthermore, the generated porous networks with a narrow pore size distribution in the LDH/CNT/GNS composite were also demonstrated by the N2 adsorption/desorption experiment. Such morphology would be favorable to improve the mass transfer and electrochemical action of the electrode. As supercapacitor electrode material, the LDH/CNT/GNS hybrid exhibited excellent electrochemical performance, including ultrahigh specific capacitance (1562 F/g at 5 mA/cm(2)), excellent rate capability, and long-term cycling performance, which could be a promising energy storage/conversion material for supercapacitor application.
With rising energy concerns, efficient energy conversion and storage devices are required to provide a sustainable, green energy supply. Solar cells hold promise as energy conversion devices due to their utilization of readily accessible solar energy; however, the output of solar cells can be non-continuous and unstable. Therefore, it is necessary to combine solar cells with compatible energy storage devices to realize a stable power supply. To this end, supercapacitors, highly efficient energy storage devices, can be integrated with solar cells to mitigate the power fluctuations. Here, we report on the development of a solar cell-supercapacitor hybrid device as a solution to this energy requirement. A high-performance, cotton-textile-enabled asymmetric supercapacitor is integrated with a flexible solar cell via a scalable roll-to-roll manufacturing approach to fabricate a self-sustaining power pack, demonstrating its potential to continuously power future electronic devices.
Activated cotton textile (ACT) with porous tubular fibers embedded with NiS2 nanobowls and wrapped with conductive graphene sheets (ACT/NiS2-graphene) was fabricated by a simple two-step heat treatment method. When used as a binder-free electrode, the ACT/NiS2-graphene electrode exhibited an exceptional electrochemical performance including ultrahigh initial discharge capacity (∼1710 mAh g(-1) at 0.01 C), magnificent rate performance (the discharge capacitance retained at ∼645 mAh g(-1) at 1 C after 100 cycles) and excellent cyclic stability (the discharge capacitance recovered to ∼1016 mAh g(-1) at 0.1 C after 400 cycles).
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