Ranjith Vellacheri

Self‐Supported Metallic Nanopore Arrays with Highly Oriented Nanoporous Structures as Ideally Nanostructured Electrodes for Supercapacitor Applications

Self-supported metallic nanopore arrays with highly oriented nanoporous structures are fabricated and applied as ideally nanostructured electrodes for supercapacitor applications. Their large specific surface area can ensure a high capacitance, and their highly oriented and stable nanoporous structure can facilitate ion transport.

Recent Advances in Designing and Fabricating Self‐Supported Nanoelectrodes for Supercapacitors

Abstract Owing to the outstanding advantages as electrical energy storage system, supercapacitors have attracted tremendous research interests over the past decade. Current research efforts are being devoted to improve the energy storage capabilities of supercapacitors through either discovering novel electroactive materials or nanostructuring existing electroactive materials. From the device point of view, the energy storage performance of supercapacitor not only depends on the electroactive materials themselves, but importantly, relies on the structure of electrode whether it allows the electroactive materials to reach their full potentials for energy storage. With respect to utilizing nanostructured electroactive materials, the key issue is to retain all advantages of the nanoscale features for supercapacitors when being assembled into electrodes and the following devices. Rational design and fabrication of self‐supported nanoelectrodes is therefore considered as the most promising strategy to address this challenge. In this review, we summarize the recent advances in designing and fabricating self‐supported nanoelectrodes for supercapacitors towards high energy storage capability. Self‐supported homogeneous and heterogeneous nanoelectrodes in the forms of one‐dimensional (1D) nanoarrays, two‐dimensional (2D) nanoarrays, and three‐dimensional (3D) nanoporous architectures are introduced with their representative results presented. The challenges and perspectives in this field are also discussed.

Growth control of AgTCNQ nanowire arrays by using a template-assisted electro-deposition method

The growth control of AgTCNQ nanowire arrays is achieved by using a template-assisted electro-deposition method. We find that the diffusion of the electrolyte into the nanopores plays an important role in the electro-deposition process, and an equilibrium between the reduction and diffusion is necessary to achieve continuous AgTCNQ nanowire arrays.

Highly-Ordered 3D Vertical Resistive Switching Memory Arrays with Ultralow Power Consumption and Ultrahigh Density

Resistive switching random access memories (RRAM) have attracted great scientific and industrial attention for next generation data storage because of their advantages of nonvolatile properties, high density, low power consumption, fast writing/erasing speed, good endurance, and simple and small operation system. Here, by using a template-assisted technique, we demonstrate a three-dimensional highly ordered vertical RRAM device array with density as high as that of the nanopores of the template (10(8)-10(9) cm(-2)), which can also be fabricated in large area. The high crystallinity of the materials, the large contact area and the intimate semiconductor/electrode interface (3 nm interfacial layer) make the ultralow voltage operation (millivolt magnitude) and ultralow power consumption (picowatt) possible. Our procedure for fabrication of the nanodevice arrays in large area can be used for producing many other different materials and such three-dimensional electronic device arrays with the capability to adjust the device densities can be extended to other applications of the next generation nanodevice technology.

Constructing Well-Ordered CdTe/TiO2 Core/Shell Nanowire Arrays for Solar Energy Conversion.

Well-ordered CdTe/TiO2 heteronanostructure arrays are fabricated via a convenient anodic aluminum oxide template-directed approach and applied to photoelectrochemistry and solar energy devices. Both the CdTe and TiO2 present a decent crystalline quality. In comparison to the photoanode with only TiO2 nanotube array, the CdTe/TiO2 heteronanostructure electrodes possess a dramatic performance improvement.

Nickel nanopore arrays as promising current collectors for constructing solid-state supercapacitors with ultrahigh rate performance

In this work, nickel nanopore arrays with a highly-oriented nanoporous structure inherited from porous alumina membranes were used as nanostructured current collectors for constructing ultrahigh rate solid-state supercapacitors. A thin layer of poly(3,4-ethylenedioxythiophene) (PEDOT) as electroactive materials was conformally coated onto nickel nanopores to form heterostructured electrodes. The as-prepared electrodes have a large specific surface area to ensure a high capacity, and the highly-oriented nanoporous structure of nickel nanopores reduces the ion transport resistance, allowing the ions in the solid-state electrolytes to quickly access the PEDOT surface during the fast charge-discharge process. As a result, the assembled solid-state supercapacitor in a symmetric configuration exhibits an ideal capacitive behavior and a superior rate capability even at an ultrahigh scan rate of 50 V∙s‒1.