Ti3C2T x , a 2D titanium carbide in the MXenes family, is obtained from Ti3AlC2 through selective etching of the Al layer. Due to its good conductivity and high volumetric capacitance, Ti3C2T x is ...regarded as a promising candidate for supercapacitors. In this paper, the fabrication of Ti3C2T x /RGO composites with different proportions of Ti3C2T x and RGO is reported, in which RGO acts as a conductive “bridge” to connect different Ti3C2T x blocks and a matrix to alleviate the volume change during charge/discharge process. In addition, RGO nanosheets can serve as a second nanoscale current collector and support as well for the electrode. The electrochemical performance of the as-fabricated Ti3C2T x /RGO electrodes, characterized by CV, GCD, and EIS, are also reported. A highest specific capacitance (C s) of 154.3 F/g at 2 A/g is obtained at the Ti3C2T x : RGO weight ratio of 7:1 combined with an outstanding capacity retention (124.7 F/g) after 6000 cycles at 4 A/g.
Aligned reclaimed carbon fiber (RCF) was reused as a conductive support to load hierarchical molybdenum disulfide (MoS2) spheres and thus MoS2/RCF composite was constructed. The synthesis of MoS2 and ...its loading were simultaneously completed during a facile hydrothermal process. This MoS2/RCF was directly utilized as the negative electrode for supercapacitor without any further process, which exhibited superior electrochemical performance: A specific capacitance of 225 F g−1 at 0.5 A g−1. Furthermore, an asymmetric supercapacitor (ASC) was assembled by coupling this MoS2/RCF electrode (−) with MnO2/RCF electrode (+), which delivered an energy density of 22.5 W h kg−1 at a power density of 703 W kg−1 over a wide potential range of 1.7 V. This RCF may be a promising conductive support candidate for those electrodes in the energy storage devices.
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Reduced graphene oxide (RGO) on nickel hydroxide (Ni(OH)2) film was synthesized via a green and facile hydrothermal approach. In this process, graphene oxide (GO) was reduced by nickel foam (NF) ...while the nickel metal was oxidized to Ni(OH)2 film simultaneously, which resulted in RGO on Ni(OH)2 structure. The RGO/Ni(OH)2 composite film was characterized using by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and field-emission scanning electron microscope (FESEM). The electrochemical performances of the supercapacitor with the as-synthesized RGO/Ni(OH)2 composite films as electrodes were evaluated using cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), electrochemical impedance spectrometry (EIS) in 1M KOH aqueous solution. Results indicated that the RGO/Ni(OH)2/NF composite electrodes exhibited superior capacitive performance with high capability (2500mFcm−2 at a current density of 5mAcm−2, or 1667Fg−1 at 3.3Ag−1), compared with pure Ni(OH)2/NF (450mFcm−2 at 5mAcm−2, 409Fg−1 at 3.3Ag−1) prepared under the identical conditions. Our study highlights the importance of anchoring RGO films on Ni(OH)2 surface for maximizing the optimized utilization of electrochemically active Ni(OH)2 and graphene for energy storage application in supercapacitors.
Abstract Black phosphorus (BP) nanostructures such as nanosheets and nanoparticles have attracted considerable attention in recent years due to their unique properties and great potential in various ...physical, chemical, and biological fields. In this article, water-soluble and biocompatible PEGylated BP nanoparticles with a high yield were prepared by one-pot solventless high energy mechanical milling technique. The resultant BP nanoparticles can efficiently convert near infrared (NIR) light into heat, and exhibit excellent photostability, which makes them suitable as a novel nanotheranostic agent for photoacoustic (PA) imaging and photothermal therapy of cancer. The in-vitro results demonstrate the excellent biocompatibility of PEGylated BP nanoparticles, which can be used for photothermal ablation of cancer cells under irradiation with NIR light. The in-vivo PA images demonstrate that these BP nanoparticles can be efficiently accumulated in tumors through the enhanced permeability retention effect. The resultant BP nanoparticles can be further utilized for photothermal ablation of tumors by irradiation with NIR light. The tumor-bearing mice were completely recovered after photothermal treatment with BP nanoparticles, in comparison with mice from control groups. Our research highlights the great potential of PEGylated BP nanoparticles in detection and treatment of cancer.
Persistent luminescence has shown great potential in anticounterfeiting technology benefiting from the feature of free background. However, current anticounterfeiting technology faces the challenges ...of low security and inconvenience, because these challenges are mainly based on visible light. Herein, we report the preparation of nanoscale Zn2Ga2Sn0.5O6:Yb3+-Ni2+ (ZGSO:Yb–Ni) phosphors with strong invisible persistent luminescence in the second near-infrared (NIR-II) window to meet the challenge. The nanoscale ZGSO:Yb–Ni phosphors (50–500 nm) were successfully prepared through the combination of a modified hydrothermal method and a subsequent annealing process. The resultant nanoparticles exhibit an intense NIR-II fluorescence at 1349 nm under the excitation of 254 nm light, and the persistent luminescence can last for ∼5 min after the excitation is switched off. A phosphor-based pattern was fabricated with resultant NIR-II nanopowders, and it shows high concealment, flexibility, and signal-to-noise ratio in the proof-of-concept experiment. These results demonstrate that ZGSO:Yb–Ni phosphors have great potential in anticounterfeiting applications.
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A unique MoS2/RGO/Ni3S2 nanosheet-on-nanosheet composite was designed and constructed on Ni foam substrate. As prepared MoS2/RGO/Ni3S2 composite was directly utilized as ...supercapcacitor electrode, which performed superior electrochemical performance: a capacitance up to 8.841Fcm−2at 50mAcm−2 (1235.3Fg−1at 7Ag−1), and retention 98.4% even after 11,000 cycles at high rate of 80mAcm−2.
MoS2/RGO/Ni3S2 nanocomposite with a unique nanosheet-on-nanosheet structure was prepared through a hydrothermal process by depositing a MoS2 layer on the upper surface side of reduced graphene oxide (RGO) nanosheets and Ni3S2 layer on the lower surface sides. Furthermore, this, MoS2/RGO/Ni3S2 nanocomposite was simultaneously loaded on a Ni foam (NF) substrate. During the synthesis process, nickel foam serves not only as a support but also as the Ni source for the composite and a reductant of GO. When used as an electrochemical electrode, as-prepared MoS2/RGO/Ni3S2@NF, it exhibited excellent electrochemical performance with a high capacity of 8.841Fcm−2at 50mAcm−2, and excellent cyclability, exhibiting capacity retention of 98.4% after 11,000 charge-discharge cycles at the current density of 80mAcm−2.
A nanocomposite consisting of CuO, reduced graphene oxide (rGO) and Cu
2
O nanoparticles was hydrothermally and in-situ deposited on a copper foil. The composite contains 3 kinds of interfaces, ...namely CuO/rGO, rGO/Cu
2
O and Cu
2
O/Cu. This facilitates redox reactions to occur between graphene oxide and the copper foil, and also leads to electrostatic attraction between the positively charged copper ions and negatively charged rGO. This, in turn, leads to improved electron and ion transfer. The modified foil is shown to directly act as a sensor for amperometric detection of both glucose (at 0.65 V vs SCE) and hydrogen peroxide (at −0.3 V). Figures of merit for sensing glucose (in 0.1 M NaOH) include (a) an ultrahigh sensitivity of 3401 µA·mM
-1
·cm
-2
, (b) a limit of detection as low as 0.10 μM, (c) a linear detection range extends from 0.5 μM to 8.3 mM, and (d) a response time of <0.5 s. As for sensing hydrogen peroxide (at pH 7), the sensitivity is 366.2 µA·mM
-1
·cm
-2
, the limit of detection is 0.05 μM, the linear range extends from 0.5 μM to 9.7 mM, and the response time is 0.8 s.
Graphical abstract
Schematic of a CuO/rGO/Cu
2
O/Cu nanocomposite in-situ-grown on Cu foil through a one-pot hydrothermal approach. The CuO/rGO/Cu
2
O/Cu directly acts as a nonenzymatic glucose and hydrogen peroxide sensor with an ultrahigh sensitivity, low detection limit and wide detection range.
Perovskites are one of the efficient catalysts for the oxygen evolution reaction (OER), and they belong to the primary ABO
in which the A site and B site are site-substituted, and oxygen vacancies ...are introduced. Further improvement of these complex perovskites is the next necessary topic for specific applications. Herein, two complex perovskites, La
Sr
Co
Fe
O
(LSCF) and Ba
Sr
Co
Fe
O
(BSCF), are exploited as the examples to demonstrate the double cation defects-introduced method of A1 and A2 to supply superimposed enhancement of the activity and stability. This is based on the fact that the increased content of oxygen vacancies and coordination can balance the oxygen vacancy and B-site element oxidation state. The electrochemical measurements revealed that the optimized A-LSCF10 and A-BSCF10 both exhibit outstanding OER catalytic activity. A small Tafel slope (57 mV dec
) and a low overpotential (228 mV at 10 mA cm
) for A-LSCF10 (vs 93 mV dec
and 345 mV at 10 mA cm
for A-LSCF0), and a small Tafel slope (65 mV dec
) and an overpotential (242 mV at 10 mA cm
) for A-BSCF10 (vs 66 mV dec
and 308 mV at 10 mA cm
for A-BSCF0) are determined, as well as good stability for 24 h.
Rhizoma Paridis, as a Traditional Chinese Medicine (TCM), has been used in clinic for thousands of years. Recently, the hepatic toxicity was reported in some published articles while its ...hepatotoxicity mechanisms have not been well established. Therefore, the present study was performed to determine the effect of Rhizoma Paridis treatment on the lipid deposition and metabolism, oxidative stress and mitochondrial dysfunction, and explore the underlying molecular mechanism through L02 cell, rat and zebrafish larvae. Rhizoma Paridis could diminish cell activity and cell proliferation, brought on cell apoptosis and elevated the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) compared with the control group, as evaluated in cell cultures. Rhizoma Paridis could result in the change of the liver structure and the liver function in the rat model and zebrafish larvae. Our results showed that Rhizoma Paridis could increase hepatic lipid accumulation, which was similar to the previous study and probably exerted toxic effect through intensive fatty acid lipogenesis, inhibition of fat degradation. Meanwhile, this experiment highlighted the importance of the oxidative stress, mitochondrial dysfunction, ER function, and the inflammation response in Rhizoma Paridis-induced disorder of hepatic lipid metabolism, which proposed a novel mechanism for interpretation of Rhizoma Paridis exposure inducing the disorder of lipid metabolism in vertebrates. Furthermore, the result of this experiment suggested that the toxicity response of zebrafish larvae was similar to the conventional model with a significant advantage.
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La3+ and F− co-doped Li4Ti5O12 (LTO) anode materials are synthesized successfully via a solid state reaction. The structure and morphology are characterized by XRD, SEM and EDS. The results indicate ...that La3+ and F− ions were uniformly dispersed in Li4Ti5O12 lattice without changing the structure and morphology of Li4Ti5O12. Li3.95La0.05Ti5O11.7F0.3 (La005-F03) exhibits an outstanding electrochemical performance among all the samples in a potential range from 0.5 to 2.5 V, and delivers a discharge capacity of 103 mAh g−1 at 10C rate, whereas the LTO only gives 62.5 mAh g−1. The sample La005-F03 retains a discharge capacity of 170.1 mAh g−1 after 100 cycles at 1C rate. The improved electrochemical performance could be attributed to the appropriate co-doping with La3+ and F−, which can increase the amount of Ti3+/Ti4+ mixing as charge compensation, leading to the decrease of the charge transfer resistance and improvement of the electronic conductivity and lithium ion diffusion coefficient.
•La3+, F− co-doped Li4Ti5O12 materials are synthesized via a solid state reaction.•La3+ and F− ions enter the different sites of the crystal structure of Li4Ti5O12.•La3+ and F− co-doping can improve the capacity and maintain the cycling stability.•Li3.95La0.05Ti5O11.7F0.3 exhibits excellent rate and better cycle performance.
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