Surface acoustic wave delay lines with an operational frequency of 2.5 GHz have been designed to measure the acousto-electric transport of carriers in graphene transferred onto YX128°-LiNbOpiezoelectric substrate. The monolayer of graphene on LiNbOpresented sheet resistance in the range of 733-1230 Ω/□ and ohmic contact resistance with gold of 1880 to 5200 Ωm. The measurements with different interaction lengths on graphene bars have allowed the extraction of carrier absorption and mobility parameters from acousto-electric current. Graphene presented higher acousto-electronic interaction in the GHz range than previously reported values in the range of 100s MHz with carrier absorption losses of 109 mand mobility for acoustically generated charges of 101 cmVs.
Facilitating rapid charge transfer in electrode materials necessitates the optimization of their ionic transport properties. Currently, only a limited number of Li/Na-ion organic cathode materials have been identified, and those exhibiting intrinsic solid-phase ionic conductivity are even rarer. In this study, we present tetra-lithium and sodium salts with the generic formulae: A-Ph-CHP and A-Ph-PhP, wherein A = Li, Na; Ph-CHP = 2,5-dioxido-1,4-phenylene bis(methylphosphinate); Ph-PhP = 2,5-dioxido-1,4-phenylene bis(phenylphosphinate), as novel alkali-ion reservoir cathode materials.
Sensors and Biosensors Group, Analytical Chemistry and Electrochemistry Lab (LR99ES15), University of Tunis El Manar, Tunis El Manar, 2092 Tunis, Tunisia. Electronic address:
Improper use and harmful effects of nitrite ions pose a significant risk to human health. To address this concern, the use of carbon-based materials for electrochemical sensing is regarded as one of the most promising detection tools for ensuring the quality of drinking water and food products. In this context, we developed laser-ablated graphene electrodes (LAGEs) by direct laser scribing on a polyimide substrate, which were subsequently modified by electrochemical deposition of a redox-active melanin-like film (MeLF/LAGEs).
Raman spectroscopy is a powerful analytical method widely used in many fields of science and applications. However, one of the inherent issues of this method is a low signal-to-noise ratio for ultrathin and two-dimensional (2D) materials. To overcome this problem, techniques like surface-enhanced Raman spectroscopy (SERS) that rely on nanometer scale metallic particles are commonly employed.
Exposure to high temperatures during indoor and outdoor activities increases the risk of heat-related illness such as cramps, rashes, and heatstroke (HS). Fatal cases of HS are ten times more common than serious cardiac episodes in sporting scenarios, with untreated cases leading to mortality rates as high as 80%. Enhancing thermal comfort can be achieved through heat loss in enclosed spaces and the human body, utilizing heat transfer mechanisms such as radiation, conduction, convection, and evaporation, which do not require initial energy input.
Transition metal oxides (TMOs) can accelerate the sluggish kinetics of vanadium redox reaction, but face challenges like limited active sites and difficulties in nanometerization, highlighting the urgent need for new TMO electrocatalysts for vanadium redox flow battery (VRFB). CoMoO features high electrochemical activity, numerous redox sites, flexible control, and short electron pathways. Herein, a high catalytic and super stable graphite felt electrode modified in situ with network cross-linking CoMoO nanosheets (CoMoO@GF) was prepared via hydrothermal and heat treatment method to enhance VRFB performance.
