Archana Mallik

Synthesis and characterization of conductive few layered graphene nanosheets using an anionic electrochemical intercalation and exfoliation technique

The mechanism of electrochemical intercalation resulting in the expansion and exfoliation behavior of the pyrolytic graphite sheets is described. In this paper, an efficient and simple process of the intercalation of perchlorate anions from a simple protic solvent at various electrolytic concentrations using a two electrode system is reported. The intercalate concentration plays a major role in the as-prepared exfoliated few layered graphene nanosheets (FLGNSs). The in situ oxygenation and hydroxylation of the FLGNSs has been painstakingly analyzed using X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy and UV-visible spectroscopy. Furthermore, the nature of the exfoliated FLGNSs colloidal was determined using field emission scanning electron microscopy, transmission electron microscopy as well as dynamic light scattering techniques. From the various analytical results obtained, it is found that the synthesized GNSs consist of FLGNSs with surface oxygenation. The extent of the surface oxygenation was found to be increased with an increase in the concentration of the intercalate. The exfoliated colloidal graphene obtained at an optimum electrolytic condition shows a stable dispersion and the highest conductivity was ∼0.87 mS cm−1. Furthermore, the conductivity of the oven dried colloidal graphene on a fluoride treated glass slide was successfully used in a light emitting diode fabrication test.

Analysis of Effect of Ultrasound on the Magnetic Topography of Electroplated Ni Films by Magnetic Force Microscopy (MFM)

It has been shown to be extremely beneficial to employ power ultrasound to assist electrochemical processes. Considerable mass transport has been demonstrated with the application of ultrasound. The magnetic microstructure, magnetic phase, and orientation images show better magnetic particle deposits in the presence of a sonication environment. Furthermore, deposits with ultrasound show permanent dipole moment magnetization. Hence, Ni film synthesis in presence of ultrasound may open new heights for hard disk drives.

A short review on the advancements in electroplating of CuInGaSe2 thin films

Thin-film solar cell devices based on copper indium gallium diselenide (CIGSe) chalcogenide materials fabricated by vacuum-based deposition techniques have already achieved lab scale efficiency beyond 21%. For industrial-scale applications, non-vacuum deposition technique such as electrodeposition and screen printing is considered to be suitable approaches for reducing the device fabrication cost. Moreover, electrodeposition has the potential to prepare large area thin films as it requires cheap raw material sources and equipment capital. Hence, it is imperative to understand the current status and advancements in the electroplating techniques of the CIGSe thin films. This article reviews on the experimental advances in electroplating of ternary CuInSe2 and quaternary CIGSe. Various approaches in electrodeposition, influential experimental parameters, and the deposition mechanisms which are related to the final cell efficiency are discussed in detail.