Rajnish Dhiman

Malaviya National Institute of Technology Jaipur · Department of Physics

Two-dimensional (2D) monometal boron nanosheets (BNS) are emerging as a promising candidate, demonstrating high catalytic performance by virtue of their tunable surface chemistry, large surface area, superb hydrophilicity, and swift charge transfer kinetics. Nonetheless, oxidation and restacking of these nanosheets in ambient air make it challengin...

Antibacterial activity of the silver decorated reduced graphene oxide (Ag-rGO) nanocomposites have been investigated against E. coli as a model for gram-negative bacteria. The effect of temperature during the hydrothermal treatment of Ag-rGO nanocomposites synthesized by simultaneous reduction of GO and Ag¬NO3 over the antibacterial activity has be...

Combining multilayered structure, tunable physicochemical, and surficial properties, two-dimensional Ti3C2Tx MXene has been extensively investigated for their potential in field of noble-metal free electrocatalysis. However, easy aggregation of MXene nanosheets and their thermodynamic instability drastically reduce active sites and, hence, decline...

Molybdenum Disulfide (MoS 2) is a two-dimensional material having hexagonal crystal structure, which is widely used as a catalyst in various electrochemical reactions. In the present work, 2H-MoS 2 nano-structures are synthesized in the exfoliated form by a facile hydrothermal synthesis route and are studied as electrode material for electrochemica...

Molybdenum Disulfide (MoS2) is a two-dimensional material having hexagonal crystal structure, which is widely used as catalyst in various electrochemical reactions. In the present work, 2H-MoS2 nano-structures are synthesized in the exfoliated form by a facile hydrothermal synthesis route and are studied as electrode material for electrochemical de...

Searching for cost-effective and highly efficient bifunctional electrocatalyst is imperative for developing an integrated energy harvesting system. 2D MXene, Ti3C2Tx has been reported as a promising candidate for catalysing hydrogen evolution reaction (HER) owing to its fascinating physiochemical properties. However, the search for its potential in...

The present work reports a quasi-solid state sodium ion-based asymmetric supercapacitor (ASC) device with nitrogen-doped reduced graphene oxide (NrGO) and boron-doped reduced graphene oxide (BrGO) electrodes. The choice of NrGO (BrGO) for the cathode (anode) is accomplished through a computational investigation of electrode quantum capacitances bas...

Basic understanding of surface reactions on the Li ion battery electrodes is of great importance as the interphase layers formed on the electrode surface due to the decomposition of electrolyte, during the initial battery cycles affects the safety, cycling life and performance of lithium-ion batteries. The effects of time, potential and cycling rat...

In the present work, Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, x-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were employed to ascertain the grafting of an organic layer of polyvinyl alcohol (PVA) onto the surface of semiconducting SiC nanocrystals using a novel metho...

Polyvinyl alcohol (PVA) grafted SiC (PVA-g-SiC)/PVA nanocomposite was synthesized by incorporating PVA grafted silicon carbide (SiC) nanocrystals inside PVA matrix. In-depth structural characterization of resulting nanocomposite was carried out using fourier transform infrared spectroscopy (FTIR), raman spectroscopy and X-ray diffraction (XRD) meas...

Polyvinyl alcohol (PVA)-SiC nanocomposite films were prepared by incorporating functionalized Silicon Carbide (f-SiC) nanocrystals in PVA matrix. Structural characterization of SiC nanocrystals before and after the functionalization was carried out using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Thermogravimetric a...

The development of SiC wafers with properties suitable for electronic device fabrication is now well established commercially. A critical issue for developing metal–oxide–semiconductor field effect transistor devices of SiC is the choice of dielectric materials for surface passivation and insulating coatings. Although SiO2 grown thermally on SiC is...

Nanocomposites of PVA with Ag nanoparticles dispersed in it were synthesized using solution casting method. The morphology and size distribution of Ag nanoparticles embedded in PVA matrix were obtained by transmission electron microscopy (TEM) and Field emission scanning electron microscopy (FE-SEM). Raman spectroscopy was used to examine structura...

The catalyst performance in a proton exchange membrane fuel cell (PEMFC) depends on not only the choice of materials, but also on the electrode structure and in particular on the interface between the components. In this work, we demonstrate that the hot-pressing conditions used during electrode lamination have a great influence on the catalyst pro...

SiC-PVA nanocomposite films, synthesized using solution-casting technique were structurally characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. Morphological studies of the SiC-PVA nanocomposite films were carried out using Transmission electron microscopy (TEM) and Scanning electron m...

In the presented work, the electrochemical stability of platinized silicon carbide is studied. Post mortem transmission electron microscopy and X-ray photoelectron spectroscopy were used to document the change in morphology and structure upon potential cycling of Pt/SiC catalysts. Two different potential cycle ageing tests were used in order to acc...

A systematic adsorption study of perfluorinated sulfonic acid Nafion ionomer on ribbon-type highly graphitized carbon nanofibers (CNFs) was carried out using fluorine-19 nuclear magnetic resonance spectroscopy. On the basis of the values obtained for the equilibrium constant (Keq , derived from Langmuir isotherm), the ionomer has varying affinities...

Research with proton exchange membrane fuel cells has demonstrated their potential as important providers of clean energy. The commercialization of this type of fuel cell needs a breakthrough in the electrocatalyst technology to reduce the relatively large amount of noble metal platinum used with the present carbon based substrates. We have recentl...

We have studied the growth and properties of SiC films on Si wafers, under ultrahigh vacuum background conditions, using a remote-, microwave excited, methane plasma as a source of active carbon and hydrogen, while the Si substrates were held at a temperature of near 700 °C. The reaction is diffusional and should thus be self-limiting, but it actua...

A robust catalyst support is pivotal to Proton Exchange Membrane Fuel Cells (PEMFCs) to overcome challenges such as catalyst support corrosion, low catalyst utilization and overall capital cost. SiC is a promising candidate material which could be applied as a catalyst support in PEMFCs. SiC nanocrystals are here synthesized using nano-porous carbo...

Cu nanoparticles were synthesized in PVA matrix by chemical reduction of cupric nitrate with hydrazine hydrate. Structural characterization of synthesized Cu–PVA nanocomposite was carried out using UV–Visible Spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Appearance of character...

Cu nanoparticles were synthesized in PVA matrix by chemical reduction method. Structural characterization of synthesized Cu-PVA nano composite was carried out using UV-Visible Spectroscopy, Transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Appearance of characteristic SPR peak of Cu nanoparticles at 591 nm in absor...

We have synthesized pre-shaped SiC/Si ceramic material elements from charcoal (obtained from wood) by impregnation with molten silicon, which takes place in a two-stage process. In the first process, a porous structure of connected micro-crystals of β-SiC is formed, while, in the second process, molten Si totally or partly infiltrates the remaining...

Synthesis of structured silicon carbide materials can be accomplished using wooden materials as the carbon source, with various silicon impregnation techniques. We have explored the low cost synthesis of SiC by impregnation of carbon from wood with SiO gas at high temperatures, which largely retains the structure of the starting wood (shape memory...

We have achieved a catalyst free, low cost, easy synthesis of straight and uniform, high-aspect ratio β-SiC nanowhiskers (of 25–100nm diameters), and a suitable separation technique to produce large quantities of individual whiskers. We conclude that these nanowhiskers nucleate on initially formed SiC clusters by a sequential gas–gas-surface reacti...

SiC nano-whiskers may become important functional elements of future micro-electro-mechanical-systems (MEMS) components and gas sensors. We have developed some relatively easy procedures to form such SiC nanostructures from saw dust. The whiskers have been characterized by Raman mcroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM)...

Future sensing elements should be more specific, more sensitive, more reversible, and faster than today's elements. These future sensing devices will either be integrated with suitable signal detection circuitry, typically based on Si microelectronics, or with optical signal detection, and finally interfaced to relevant state-of-the-art signal reco...