Graphene-based Nanomaterials for Fabrication of ‘Pesticide’ Electrochemical Sensors

At present, graphene is one of the most up-to-date materials and it can be applied for various energy conversion devices and sensor technology. In this review article, our main focus is to summarize the role of graphene and its modified surface leading to develop hybrid nanomaterials and its applications in fabrication of pesticide sensor. Graphene based materials demonstrate exclusive electrochemical and optical properties as well as compatibility to absorb a variety of bio-molecules through π-π stacking interaction and/or electrostatics interaction, which make them ideal material to be employed in sensor application. The role of graphene is very crucial in preparing different unique and desirable hybrid functional composites along with nanoparticles, redox mediators, conducting polymers etc. to improve the performance of the sensors. Therefore, they can be easily used as a suitable material applying in fabrication of electrochemical sensors/ biosensors for the detection of organophosphorous and carbamate pesticides. A number of most recent reported works were discussed in which graphene-based hybrid composites show high sensitivity, good catalytic activity, selectivity towards the determination of pesticide either enzymatically or nonenzymatically. The properties of graphene (exceptional charge transport, thermal, optical, mechanical, high surface area, large pore volume and size, an opened ordered structure) play an important role in pesticide detection.

Recent Advancement in MoS2 for Hydrogen Evolution Reactions

The economic growth of any country depends on certain factors of which energy is a part and even prominent. The global economy has depended heavily on fossil fuels as the main source of reliable energy for so many decades. Their adverse long-term impact on society has led to a substantial increase in research activities both in industry and academia. Most of the research has been dominated by the development of green energy technologies and the expansion of such technologies in order to meet increasing future demands of energy. Prominent among the research drive is the development of fuel cells, whose driving force comes from hydrogen. This is because hydrogen is economical considering its relative abundance, low cost, yet high activity in production. Materials such as Pt, C, Fe, MoS2 have gained popularity in the production of hydrogen for use in fuel cell devices. The high efficiency of MoS2, amorphous or crystalline, in hydrogen evolution reactions (HER) depends on a suitable architecture that increases the exposure of its edge sites. Such architecture could be determined by the design of catalysts in terms of proportions of molybdenum and dopant ions, the composite structure between MoS2 and electrically conductive materials, synthesis temperature and the synthesis method. Therefore, a review is made on recent achievements for different nanoarchitectures of MoS2 as well as its composite structures for use as electro-catalysts in HER performance and future prospects.

Strategies for Development of High-Performance Graphene-Based Supercapacitor

The development of high-performance supercapacitors requires efforts in materials design and nanotechnology to provide more efficient electrodes with higher electrochemical window, capacitance, energy and power density. In terms of candidates for electrodes, the high surface area of graphene (2630 m2g-1) makes this carbon derivative a widely explored building block for supercapacitor electrodes. Herein, it is presented a review about the state-of-art in surface modification of graphene derivatives with the aim of avoiding restacking processes in nanosheets. It allows that Faradaic and non-Faradaic mechanisms can be synergically explored to reach not only superior results in power density but in energy density, a typical drawback in supercapacitors (by comparison with conventional batteries), introducing graphene-based supercapacitors as promising candidates for energy storage devices.

A Roadmap for the Chalcogenide-graphene Composites Formation Under a Glassy Regime

Background: Nano-composite is an innovative material having nano in which fillers dispersed in a matrix. Typ-ically, the structure is a matrix- filler combination, where the fillers like particles, fibers, or fragments are surrounded and bound together as discrete units by the matrix. The term nano-composite encompasses a wide range of materials right from three dimensional metal matrix composites to two dimensional lamellar composites. Therefore, the physical, chemical and biological properties of nano materials differ from the properties of individual atoms and molecules or bulk matter. The chalcogenide – graphene composites in glassy regime is the growing novel research topic in the area of composite material science. It is obvious to interpret such materials different physicochemical mechanism. Objective: The key objective of this research work to explore the internal physicochemical mechanism of the chalcogenide – graphene composites under the glassy regime. Including the prime chalcogen alloying element selenium amorphous atomic structure and their fullerene like bonding nature. By accommodating the essential properties of the stacked layers of bilayer graphene. The diffusion, compression and dispersion of the bilayer graphene in selenium rich ternary (X(1-x-y)-Y(x)- Z(y) + GF (bilayer graphene); X = Se, Y = Semimetal or metalloid, Z = None metal) alloys under the complex regime on and after thermal melting process are addressed. Materials and Methods: To synthesize the composite materials the well-known melt quenched method had adopted. More-over, to interpret the amorphous selenium (Se8) chains and rings molecular structures we had used vista software with an available CIF data file. While to show the armchair and zig-zag bonds with bilayer graphene structure the nanotube modeler simulation software has used. Results: Outcomes of this study reveals the chalcogenide -graphene nano composite formation under a glassy regime changes the individual materials structural and other physical properties that is reflecting in different experimental evi-dences, therefore, the modified theoretical concepts for the different properties of such composite materials are interpreted in this study. Discussion: The dispersion and diffusion of the high stiff graphene bonds in low dimension chalcogen rich alloys has been interpreted based on their quadric thermal expansion behaviour. In addition to this, a possible bond angle modification in the formation of X(1-x-y)-Y(x)- Z(y) + GF composites are also addressed. To interpret the distinct optical property behavior of the formed X(1-x-y)-Y(x)- Z(y) + GF composites and parent chalcogenide glassy alloys a schematic model of the energy levels is also addressed. Conclusion: To make a better understating on the formation mechanism such composites, the diffusion and deformation of high stiff graphene σ and π bonds in a low dimension chalcogenide alloy basic mechanism are discussed on basis of novel “thermonic energy tunneling effect” concept, which could result in quadratic thermal expansion of graphene. Moreover, the structural unit modifications of such composite materials are described in terms of their bond angle modifications and in-fluence of the coordination defects. The energy levels suppression and creation of addition sub energy levels in such com-posite materials are discussed by adopting the viewpoint impact of the foreign alloying elements and surface π-plasmonic resonance between the graphene layers in the honeycomb band structure. Thus, this study has described various basic aspects of the chalcogenide system – bilayer graphene composites formation under a glassy regime.

Graphene and its Composite Materials for Water Decontamination

Acute water cataclysm on account of eco-noxious anthropogenic exploitation caused massive setbacks on the global prerequisite of clean water. Subsequently, with the purpose of circumventing the worldwide unpolluted water deficiency, wastewater treatment technologies have received extraordinary precedence to disinfect water for a sustainable environment. Presently, diverse, efficient materials are being used to remove organic/ inorganic noxious substances from wastewater, among which graphene and its composites have received remarkable attention for water decontamination technology by virtue of their substantial surface area, mechanical strength, mesoporosity, nanosheet arrangement and outstanding absorption proficiency for the contaminant. The present review accentuates the contemporary progresses in the implementation of graphene along with its composite as a potential adsorbent for the exclusion of pernicious inorganic mixture of miscellaneous pollutants, as photocatalysts for the breakdown of venomous organic toxins by employing photocatalytic oxidation. The prospect of graphene and its nanocomposites towards comprehensive water treatment approaches has been discussed.

Short Review and opinion: New matter properties and applications based on Hybrids Graphene based Metamaterials

: Graphene as Organic material showed special attention due to their electronic and conductive properties. Moreover, its highly conjugated chemical structures and relative easy modification permitted varied design and control of targeted properties and applications. In addition, this Nanomaterial accompanied with pseudo Electromagnetic fields permitted photonics, electronics and Quantum interactions with their surrounding that generated new materials properties. In this context, this short Review, intends to discuss many of these studies related with new materials based on graphene for light and electronic interactions, conductions, and new modes of non-classical light generation. It should be highlighted that these new materials and metamaterials are currently in progress. For this reason it was showed and discussed some representative examples from Fundamental Research with Potential Applications as well as for their incorporations to real Advanced devices and miniaturized instrumentation. In this way, it was proposed this Special issue entitled “Design and synthesis of Hybrids Graphene based Metamaterials”, in order to open and share the knowledge of the Current State of the Art in this Multidisciplinary field.

Synthesis and characterization of metallic sulfide NPs doped graphene oxide for methylene blue adsorption to leuco methylene blue in aqueous mixture

Introduction: The Metal Sulfide Nanoparticles Doped Graphene Oxide Sheets Have Been Studied And Were Used To Adsorb Fluorescent Methylene Blue Dye. Such Mechanism Efficiently Reduces The Dyes And Their Fluorescent Pollutants Through The Positive And Negative Holes. The Metal Sulfide Doped Graphene Oxide Could Be A Most Potential Route To Reduce From Fluorescent To Non-Fluorescent Species To Prevent The Global Warming And Other Pollution Being Caused By Them. Objectives: This Study Has Been To Strengthen And Widen The Applications Of Negative And Positive Holes Quick Formation At A Negligible Energy Barrier. Metal Sulfide Nanoparticles Were Doped With Graphene Oxide To Further Strengthen The Semiconducting And To Fastened The Rate Of Adsorption Of Methylene Blue Dye. Methods: Graphite Flakes Were Oxidized To Graphite Oxide With High Yield. The Graphite Oxide Was Sonicated In Water To Obtain Graphene Oxide And Doped With Metal Sulfide Nanoparticles In Situ. The Samples Were Characterized With High End Instruments And Used For Adsorption. Results: The Metal Sulfide Nanoparticles Were Successfully Doped With Graphene Oxide. The Ftir And Xps Spectra Infer Doping Of Metal Sulfide Nanoparticle In Graphene Oxide. That Enhanced Methylene Blue Adsorption Upto 97%. Conclusion: The Common Adsorption Effect Of Methylene Blue With Bare Graphene Oxide And Metal Sulfide Nanoparticles Doped Graphene Oxide Were Studied In This Paper. The Methylene Blue Adsorption Was Maximum (97%) By Cadmium Sulfide Doped Graphene Oxide Compared To Bare Graphene Oxide (87%), Nickel Sulfide Doped Graphene Oxide (79%), And Zinc Sulfide Doped Graphene Oxide (89%). The Metal Sulfide Nanoparticles Have Successfully Enhanced A Semiconductor Mechanism Of Graphene Oxide Especially With 3d And 4d10 Of Cds.

Recent advances in graphene based nano-composites for automotive and off-highway vehicle applications

: Nano-composites comprised of a polymer matrix and various types of nanosized fillers have remained as one of the most important engineering materials and continue to draw great interest in the research community and industry. In particular, graphene based nano-composites with high thermal conductivity, excellent mechanical, electrical and optical properties, becomes important and promising filler for making the next generation, high performance composite materials. : Automotive and off-highway machinery industry are extensively viewed as being the industry in which the highest volume of advanced composite materials such as graphene based nano-composites will be used in the future to produce lighter, stronger, more energy-efficient, and safe vehicles. Design, modeling, analyzing and methods for large-scale production of the graphene based nano-composites in automotive and off-highway machinery applications considering it’s mechanical, functional and interface properties between the graphene and polymer matrix under severe loading conditions is challenging, potentially due to nonlinear properties, joining of dissimilar materials and high demand of computations. While graphene based material strategies have been investigated and demonstrated to be effective for structural application in various industries includes electronics, electromechanical and energy systems, currently there is limited research highlighting the specific knowledge available for design engineers and researchers concerned with lightweight and stronger solutions by use of graphene based materials for automotive off-highway vehicle applications. : The present review presents, an overview of the latest studies that utilize graphene-based nanomaterials and their composites in automotive and off-highway machinery applications. First, the paper describes the concept of traditional composites used in present engineering industries considering its advantages and limitations, then highlights the key benefits of using nanostructured carbon material, such as graphene through some recent studies available in the literature. Then depicts the various mechanisms of integrating graphene as polymer reinforcements within composite materials, which have been found based on the survey, and their related modeling, designing, and manufacturing capabilities suitable for automotive and off-highway machinery industry. Finally outlines the available experimental evidence for graphene based composites. In order to lay the groundwork for future work in this exciting area, the paper discusses close by several future prospects as well as the current challenges in this field.