Comparative studies of nanosheet-based supercapacitors: A review of advances in electrodes materials

In the construction of supercapacitors, various nanocomposites have been utilized to fabricate electrodes. Nanocomposite electrodes based on two-dimensional (2D) nanomaterials have recently received much attention due to their unique propertices. The recent development of supercapacitors was mainly summarized regarding nanosheet electrodes. The types of supercapacitors were basically compared on the basis of electrode materials, cyclic stability, specific capacitance, power, and energy densities for 2D nanomaterial electrodes as well. This Review discusses novel findings of the critical nanosheet-based supercapacitors including MXenes, graphene, and carbon nanomaterials electrodes. Comparison between the results of MXene, graphene, and carbon nanomaterials-based supercapacitors showed that the specific capacitance almost is less than 3000 F g−1 and capacitance retention is in the range of 70–100 %. This study also provides an opportunity for future researchers in the construction of energy storage devices to recognize novel breakthroughs in the fabrication of supercapacitor electrodes relevant to nanosheets

CNTs-Supercapacitors: A Review of Electrode Nanocomposites Based on CNTs, Graphene, Metals, and Polymers

Carbon nanotubes (CNTs), due to mechanical, electrical, and surface area properties and their ability to adapt to different nanocomposite structures, are very substantial in supercapacitor electrodes. In this review, we have summarized high-performance, flexible, and symmetry CNT supercapacitors based on the CNTs/graphene, CNTs/metal, and CNTs/polymer electrodes. To present recent developments in CNT supercapacitors, we discuss the performance of supercapacitors based on electrical properties such as specific capacitance (SC), power and energy densities, and capacitance retention (CR). The comparison of supercapacitor nanocomposite electrodes and their results are reported for future researchers

Recent advances in Ni-materials/carbon nanocomposites for supercapacitor electrodes

Recent advancements in Ni material-based supercapacitors have focused on their composites with carbon nanomaterials. These composites demonstrate improved electrical conductivity, enhanced surface area, and superior electrochemical performance by addressing critical issues related to cycling stability and low energy density. This review provides an overview of Ni material-based carbon nanocomposites including graphene (Ni/graphene), carbon nanotubes (Ni/CNTs), and activated carbon (Ni/AC) as potential electrodes for supercapacitors. The synergistic effects of Ni and carbon in nanocomposites on electrochemical properties such as capacitance, cycling stability, and specific capacitance are systematically outlined. The findings will serve as a valuable resource for understanding the structure-property-performance relationship of Ni-based composite materials for energy storage applications.</p

Nanoscale morphology, optical dynamics and gas sensor of porous silicon

Abstract We investigated the multifaceted gas sensing properties of porous silicon thin films electrodeposited onto (100) oriented P-type silicon wafers substrates. Our investigation delves into morphological, optical properties, and sensing capabilities, aiming to optimize their use as efficient gas sensors. Morphological analysis revealed the development of unique surfaces with distinct characteristics compared to untreated sample, yielding substantially rougher yet flat surfaces, corroborated by Minkowski Functionals analysis. Fractal mathematics exploration emphasized that despite increased roughness, HF/ethanol-treated surfaces exhibit flatter attributes compared to untreated Si sample. Optical approaches established a correlation between increased porosity and elevated localized states and defects, influencing the Urbach energy value. This contributed to a reduction in steepness values, attributed to heightened dislocations and structural disturbances, while the transconductance parameter decreases. Simultaneously, porosity enhances the strength of electron‒phonon interaction. The porous silicon thin films were further tested as effective gas sensors for CO2 and O2 vapors at room temperature, displaying notable changes in electrical resistance with varying concentrations. These findings bring a comprehensive exploration of some important characteristics of porous silicon surfaces and established their potential for advanced industrial applications