Sanjit Saha

ENSEMBLE3 sp. z o. o. · Functional Materials Technology Group

Petroleum coke is a solid, carbonaceous by-product of oil refining and is normally used for heating or as an anode in aluminum and steel production. These applications contribute to carbon emissions, but here we show that petroleum coke has another potential avenue: as a precursor for graphene production. This path presents an environmentally and e...

Molten-salt etching of Ti3AlC2 MAX phase offers a promising route to produce 2D Ti3C2Tz (MXene) nanosheets without hazardous HF. However, molten-salt etching results in MXene clays that are not water-dispersible, thus preventing further processing. This occurs because molten-salt etching results in a lack of -OH terminal groups rendering the MXene...

Titanium carbide/reduced graphene oxide (Ti3C2Tz/rGO) gels were prepared by a one-step hydrothermal process. The gels show a highly porous structure with a surface area of ∼224 m2 g-1 and average pore diameter of ∼3.6 nm. The content of GO and Ti3C2Tz nanosheets in the reaction precursor was varied to yield different microstructures. The supercapac...

The need for reliable metrics for characterizing graphene nanosheet thickness and quality has increased, particularly as graphene production is scaled beyond kg-levels and utilized in a range of commercial applications. Here, we demonstrate a bulk, rapid testing methodology that distinguishes graphene from graphite based on our recent findings that...

In this paper, the effects of graphene loading and processing technique on the morphological, mechanical, thermal, rheological, and barrier properties of bromo–butyl rubber, are explored. Bromo–butyl rubber composites with electrochemically exfoliated graphene (EEG) nanosheet filler are prepared via solvent casting and/or melt blending techniques,...

This chapter contains sections titled: Introduction Scope of the Chapter Charge Storage Mechanism of Carbonaceous Materials Nanostructured Carbonaceous Materials Nanostructured Carbon‐Based Supercapacitor Device Conclusions

3D Fe3O4/NiO was grafted on to the 2D rGO/h‐BN by electro‐precipitation method. Nitrogen of h‐BN moiety and oxygen functional groups of rGO played the role of negative active site to trap the metallic cations. Electrochemical charge storage mechanism was optimized by controlling the stoichiometry and defect contents of Fe3O4/NiO@rGO/h‐BN. Stoichiom...

The typical physical and chemical properties lead the nanomaterials to breakthrough in the field of energy storage especially, supercapacitor applications. The optimization of electrical conductivity, structural flexibility, band gap and charge carrier mobility are the key point to solve the issues in the electrochemical charge storage mechanism of...

Energy storage and conversion are the primary needs for modern human civilization. In addition, depletion of fossil fuels, increasing pollution and growing demands of green energies forced the mankind to upgrade the traditional energy storage system. Power density of the traditional energy storage systems like batteries is comparatively low. Althou...

Controlled synthesis of nickel /iron multimetal oxide with different stoichiometry and particle size is carried out by varying the pH of the reaction medium. Electrodeposited samples grown at different pH showed wide range of electrochemical properties like dissimilar current response and potential window due to the formation of different stoichiom...

A band gap of ∼2.1 eV was obtained through the hybridization of reduced graphene oxide (rGO) with insulating hexagonal boron nitride (h-BN). The h-BN/rGO superlattice behaved like n type semiconductor due to the enriched electron density at the conduction band and allowed charge transfer depending on the redox potential of the electrolyte. The band...

The surface electronic property of graphene oxide (GO) was modified through reduction and functionalization. Non-covalent functionalization was found to be superior compared to covalent functionalization due to the formation of a few layer graphene with low defect content and average crystalline length. Because of the restoration of sp2 hybridizati...

Supercapacitors are one of the promising energy storage devices of future energy technology. In this regard, rapid progress is proceeding in the field of fundamental and applied aspects of supercapacitors. The development of electrode materials are the most significant factor as the electrode is the key part of electrochemical capacitors. Numerous...

Functionalization and electrodeposition of reduced graphene oxide/hexagonal boron nitride (rGO/h-BN) superlattice was carried out by a novel one-step electrochemical process. The sulfanilic acid azochromotrop (SAA) functionalized and electrodeposited nickel foam (SAA@rGO/h-BN@Ni) electrode showed high specific capacitance of ∼1300 F g⁻¹. An asymmet...

A low cost and one step synthesis of N-doped graphite nano sheet is demonstrated. Doping and pulverization of graphite flake is carried out simultaneously by mechanical milling. Doping is confirmed from the Raman spectroscopy analysis. FE-SEM image shows the porous and sheet like morphology of N-doped graphite. ZView fitted EIS analysis shows the N...

A facile, cost effective and additive-free successive ionic layer adsorption and reaction (SILAR) technique is demonstrated to develop layer-by-layer (LbL) assembly of reduced graphene oxide (RGO) and MnO2 (MnO2-RGOSILAR) on a stainless steel current collector, for designing light-weight and small size supercapacitor electrode. The transmission ele...

The effect of different content of graphene oxide (GO) on the electrical and electrochemical property of h-BN/reduced GO (rGO) hetero-structure is investigated elaborately. The increasing amount of rGO within the h-BN moiety plays fascinating role by reducing the electronic work function while increasing the density of state of the electrode. Furth...

A self-charging supercapacitor is constructed through simple integration of the energy storage and photo exited materials at the photo electrode. The large band gap of NiO/Fe3O4 heterostructure generates photo electron at the photo electrode and store the charges through redox mechanism at the counter electrode. Sulfanilic acid azocromotrop/reduced...

Potassium (K) incorporated nano-graphitic structure has been derived from cotton (Gossypium arboreum) through KOH activation followed by post annealing treatment. The outer active sites increase as compared to the inner active sites in consequence to K incorporation. Diffusion time constant also decreases with increasing surface area after K incorp...

A simple, additive-free, cost-effective and scalable successive ionic layer adsorption and reaction (SILAR) method is reported to prepare nickel-cobalt binary hydroxide (Ni-Co-BH) on reduced graphene oxide (RGO) directing template over a macro porous conductive nickel foam substrate. This green technique is not only considered as fundamental resear...

The boron doped NiO/Fe3O4 nanostructure was successfully synthesized by facile one-step hydrothermal method. The boron doping was confirmed from the decreased band gap energy and increased electrical conductivity of the NiO/Fe3O4 composite. The nyquist plot of the multi metal oxide was fitted with ZView software for the detailed understanding of th...

In-situ electro-deposition, reduction and functionalization of graphene oxide (GO) with sulfanilic acid azocromotrop (SAC) was carried out through a facile one-step electrochemical method. The nickel foam was used as the anode during the electro-deposition and the aqueous solution of SAC along with GO was used as the electrolyte. The SAC modified r...

Nano structured hexagonal boron nitride (h-BN)/reduced graphene oxide (RGO) composite is prepared by insertion of h-BN into the graphene oxide (GO) through hydrothermal reaction. Formation of super lattice is confirmed by the existence of two separate UV-visible absorption edges corresponding to two different band gaps. The composite materials show...

Sulfanilic acid azocromotrop (SAC) modified reduced graphene oxide (SAC-RGO) was prepared by simple non-covalent functionalization of graphene oxide (GO) followed by post reduction using hydrazine monohydrate. Spectral analysis (Fourier transform infrared, Raman and X-ray photoelectron spectroscopy) revealed that successful modification had occurre...

Co9S8/reduced graphene oxide (RGO) composites were prepared on nickel foam substrate through hydrothermal reaction and used directly as supercapacitor electrode. The field emission scanning electron microscopy analysis of the composites showed the formation of Co9S8 nano-rods on the RGO surfaces. The average crystal size of the Co9S8 nano rods grow...

A facile and green approach for the reduction of graphene oxide (GO) using tobacco leaves solution was reported. The benefits of this approach were the use of green and cheap reducing agent as compared to the commercially available toxic and hazardous chemicals. Moreover, the purification of reduced GO (rGO) sheets can be avoided by using naturally...

Highly porous nano-structured Fe3O4 particles were successfully prepared on the surface of reduced graphene oxide (RGO) sheets through one-step hydrothermal method. X-ray diffraction (XRD) and Field emission scanning electron microscopy analysis (FE-SEM) ensured not only the size and porous nature but also the formation of Fe3O4 and Fe2O3-based com...

The temperature of allotropic phase transformation in ZnS (cubic to wurtzite) changes with pressure and particle size. In this paper we have explored the interrelation among these through a detailed study of ZnS powders obtained by a temperature controlled high energy milling process. By employing the combined effect of temperature and pressure in...