The poor electrochemical performance of pristine WS2 is mainly due to its low conductivity which restricts the redox kinetics. Enhancement in the electrochemical performance of WS2 as negative electrodes in sodium ion battery (SIB) has been attempted by forming composites with hard carbon (HC) derived from the linear polysaccharide biopolymer chitosan. It is observed that assembling of WS2 nanostructures on N/O (nitrogen/oxygen) heteroatom loaded hard carbon sheet derived from the biowaste chitosan improves the conductivity, reduces polysulfide leaching, and balances the inherent drawback of volume alteration in the negative electrodes. The electrochemical performance of the WS2@HC electrodes is investigated by electrochemical impedance spectroscopy measurements. This work establishes that the heteroatom loaded hard carbon support provides mechanical stability and can improve the cycling stability and rate capability of WS2 by enhancing ion diffusion kinetics.

The wide application of Li-S batteries is restricted by the high resistance of sulfur, volume changes during lithiation/delithiation, and the shuttling of lithium polysulfides (LiPS). Here, we present a strategy involving composite fabrication of an imine-based diamondoid covalent organic framework (COF) and MXene as an efficient host for sulfur which can be efficiently used as cathode material for Li-S batteries. The lithiation/delithiation reactions with sulfur occur within the porous structure of COF, providing sufficient space to accommodate volume variation. Additionally, MXene not only ensures the necessary electronic conductivity but also reduces the migration of polysulfides. The efficacy of MXene as an efficient agent to restrict migration of polysulfides has been substantiated by density function theory. The cells with MXene/COF/S cathodes exhibit superior capacity, rate capability, and cycle life compared to cells with pristine COF/S electrodes. Specifically, the cell with MXene/COF/S cathode shows excellent rate performance at 0.5 A/g, delivering a reversible capacity of approximately 380 mAh/g, and maintains long-term usability over 300 cycles with low-capacity decay of 0.13 % per cycle. This work highlights the design of high-performance hybrid cathode materials, combining threedimensional (3D) diamondoid COF and MXene, with appropriate electronic conductivity and surface chemistry tailored to prevent LiPS migration and enhance lithium diffusion in Li-S batteries.

Tin dioxide (SnO2), with diverse morphological structures, stands out as a key candidate among wide bandgap semiconductors. This study examines how fabrication conditions influence the morphology of SnO2 and the subsequent effects on its physical properties across different structures, such as highly crystalline SnO2 Quantum Dots (QDs), cauliflower (CF), and kadam flower (KF). Optical and Raman studies confirm the presence of singly charged oxygen vacancies, leading to green emission in both QDs and CF. The increased surface area of QDs offers more active sites for dye adsorption, thereby enhancing photocatalytic activity. The oxygen vacancies in QDs and CF act as electron acceptors, reducing the surface recombination of electron-hole pairs. Comparative analysis shows that QDs are more effective catalysts for the photocatalytic degradation of methylene blue (MB) and rhodamine B (RhB) dyes compared to flower-like SnO2 microstructures. The rate of dye photodegradation is slower under solar light than under UV light.

The next-generation of batteries need be both energy dense and environment friendly. Lithium sulfur batteries (LSBs) satisfy both criteria but their practical implementation is marred by the highly resistive nature of sulfur. Carbon-based cathodes play a vital role in mitigating the issue because their high conductivity allows for effective electron transfer during electrochemical cycling. Synthesis and electrochemical evaluation of carbon-based cathodes from two different sources for LSBs was carried out. Herein, two kinds of carbon, namely bio-derived carbon from coconut shells (CC500) and N-doped carbon (NC) from polyacrylonitrile fibers were synthesized and sulfur was incorporated via the melt diffusion route. The composites are characterized by PXRD and TGA, which determined 80 wt

SnO2 is an excellent candidate for replacement of conventional graphite-based anodes in lithium-ion batteries. It offers four times the specific capacity of carbon and a low working potential of similar to 0.6 V vs Li+/Li but suffers from large capacity fade due to a drastic volume change (similar to 300%) upon cycling. A unique design of SnO2 quantum dots (QDs) dispersed over flexible and conducting polypyrrole (PPy) is vital for achieving a high rate capability and long cycle life. This specially designed SnO2 QDs@PPy anode delivers excellent cycle performance with discharge capacities of 1252, 723, 474, 298, and 152 mAh g(-1) at discharge rates of 0.35, 0.7, 1, 1.8, and 3.5 A g(-1). Upon long cycling at an elevated current density of 2 A g(-1), the anode demonstrated an initial discharge capacity of 572 mAh g(-1), while retaining 399 mAh g(-1) at the 1360th cycle with a very low capacity decay of 0.022% per cycle. The superior mechanical stability and conductivity of the specially designed composite may be the reason behind very high cycle stability.

A detailed experimental investigation on the thermochemical stability of Zn2Mo3O8(s) in the Zn-Mo-O system was reported for the first time using high temperature oxide melt solution calorimetry in conjunction with solid oxide based electrochemical measurements. The temperature dependence of molar heat capacity of this compound was determined employing thermal relaxation calorimetry and differential scanning calorimetry. The values of standard molar enthalpy of formation (∆fH298.15°), standard molar entropy (S298.15°), molar heat capacity (Cp) and Debye temperature (θD) for Zn2Mo3O8(s) were determined for the first time in this study. The present study also focuses on the investigation of electrochemical performance of α-ZnMoO4(s) for lithium ion battery applications which demonstrated the effective utilization of this compound as anode material due to its remarkable cycling stability and rate capability.

Lithium-Sulfur batteries with high sulfur loading cathodes are highly desirable to achieve greater energy density. In this work, a high loading composite cathode is reported that is made by scalable vacuum filtration route, eliminating the need for a binder, conducting carbon, and metallic current collector. Moreover, capacity fade due to peeling off of coated active material from current collector is avoided, leading to excellent capacity retention. The coated separator affords a porous framework to (i) accommodate volume changes during cycling, (ii) allow higher sulfur loading, (iii) allow electrolyte wetting of active material in addition to (iv) functioning as a traditional separator and current collector by pressing against stainless steel casing. The MXene/reduced graphene oxide/S8 composite with an areal loading of 2.52 mg/cm2 exhibits a specific capacity of 495 mAh/g with a capacity retention of 97.5% after 200 cycles at a charge/discharge rate of 100 mA/g. At 500 mA/g discharge rate, an initial specific capacity of 378 mAh/g was obtained with 239 mAh/g retained after 750 cycles.

The quest for better alternatives for graphite anodes is the holy grail in the field of energy storage technologies. Biomass-derived carbon has been widely explored as the energy-dense and cost-effective option but involves several pre/post-conditioning steps. In this study, kitchen chemistry concepts of fermentation have been utilized to obtain sustainable carbon anodes from readily available and cost-effective wheat flour and baker's yeast. The yeast-fermented mixture of wheat flour and MnCO3 is pyrolyzed under 500 degrees C to yield porous C-MnO composites, which have been explored as an anode for Li-ion batteries. The material showed superior electrochemical performance with an initial discharge of 1160 mAh g(-1) at 0.15 A g(-1) (after solid electrolyte interface formation). A reversible capacity of 1499 mAh g(-1) was obtained with a concomitant improvement of 30% after 160 cycles exhibiting a "negative fading effect". Excellent electrochemical behavior has been attributed to the synergistic effect of in situ synthesized, well-dispersed MnO in carbon, the presence of redox-active Mn, and well-connected porosity in nanohybrids. At a high current density of 1 A g(-1), the anode displayed an exemplary initial discharge capacity of 770 mAh g(-1) with a high initial Coulombic efficiency of 90%, which was maintained at 856 mAh g(-1) after 760 cycles. Easy synthesis and excellent electrochemical performance render this material highly promising for battery applications.

Lithium-sulphur batteries (LSBs) are a promising candidate for the next generation of high energy density, safe, green and affordable batteries but their practical utilization is hindered by several roadblocks including low cycle life, fast capacity fade, low sulfur utilization due to insulating nature of sulfur and “polysulfide shuttle”. This work employs multiple strategies to circumvent the aforementioned issues like utilizing (i) a reduced graphene oxide (rGO) conducting carbon framework for improving conductivity and mechanical stability of cathode, (ii) polyaniline conducting polymer with polar groups to restrain soluble lithium polysulfides (LiPS) by physisorption/chemisorption (iii) separator modification with graphene oxide to act as a second barrier layer to suppress LiPS migration and support the cathode current collector to enhance sulfur utilization. The combination of these strategies led to a LSB cell that exhibited high initial capacity, low capacity fade and improved lithium ion diffusion as well as lowered cell impedance. The synthesized cathode composite of PANI-rGO-sulfur (PGS) was characterized by several techniques like power x-ray diffraction, scanning electron microscopy, thermogravimetry etc. Electrochemical characterization of cells was performed by cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic cycling. The coin cell delivered a superior initial capacity of 807 mAh/g at 100 mA/g current density. Upon cycling at a high current density of 1A/g it delivered a capacity of 478 mAh/g with excellent stability for 500 cycles and lower capacity fade of 0.02% per cycle.

Lithium-sulfur batteries are a compelling choice for next-generation energy storage devices with their high energy density, low cost, and environmental friendliness. This work employs a one-pot route to synthesize a MXene/reduced graphene oxide/S composite with a graphene oxide (GO)-modified sepa-rator to overcome the common bottlenecks to successful commercialization of lithium sulfur batteries like fast capacity fade, low electrochemical utilization, and low sulfur loading. The synthesized cathode material was characterized by powder X-ray diffraction, scanning electron microscopy, thermogravim-etry, Raman spectroscopy, and X-ray photoelectron spectroscopy. Electrochemical characterization of assembled coin-cells was performed by cyclic voltammetry, galvanostatic cycling as well as by electro-chemical impedance spectroscopy. The loading of GO on the separator was varied to probe its effect and a monotonic increase in capacity with increasing GO loading was observed. GO modification of separator also results in lower cell impedance and enhanced Li+ diffusion. The optimized coin cell exhibited an initial specific capacity of 725 mAh/g when cycled at 100 mA/g current density with a capacity fade of 0.14% per cycle. Post-mortem analysis of cycled cells corroborates increased polysulfide trapping with higher GO loading on separator.& COPY; 2023 Elsevier Ltd. All rights reserved.

Indium selenides (InSe and In2Se3) have earned a special place among the 2D layered metal chalcogenides owing to their nontoxic nature and favourable carrier mobility. Additionally, they are also being projected as next generation battery anodes with high theoretical lithium-ion storage capacities. While the development of indium selenide-based batteries is still in its embryonic stage, a simple and easily scalable synthetic pathway to access these materials is highly desirable for energy storage applications. This study reports a controlled synthetic route to nanometric cubic InSe and hexagonal In2Se3 materials through proper choice of coordinating solvents from a structurally characterized air and moisture stable single source molecular precursor: tris(4,6-dimethyl-2-pyrimidylselenolato)indium(III). The crystal structure, phase purity, composition, morphology and band gap of the nanomaterials were thoroughly evaluated by pXRD, energy dispersive X-ray spectroscopy (EDS), electron microscopy (SEM and TEM), and diffuse reflectance spectroscopy (DRS), respectively. The pristine InSe and In2Se3 nanostructures have been employed as anode materials in lithium-ion batteries (LIBs). Both the cells deliver reasonably high initial discharge capacities with a cyclability of 200 and 620 cycles for cubic InSe and hexagonal In2Se3 respectively with ∼100% coulombic efficiency.

Metal sulfides are gaining prominence as conversion anode materials for lithium/sodium ion batteries due to their higher specific capacities but suffers from low stability and reversibility issues. In this work, the electrochemical properties of CuS anode material has been successfully enhanced by its composite formation using graphitic carbon nitride (g-C3N4). The CuS nanoparticles are distributed evenly in the exfoliated g-C3N4 matrix rendering higher electronic conductivity and space for volume alterations during the repeated discharge/charge cycles. The 0.8CuS:0.2g-C3N4 composite when used as an anode for lithium ion coin cell exhibits a reversible capacity of 478.4 mA h g(-1) at a current rate of 2.0 A g(-1) after a run of 1000 cycles which is better than that reported for CuS composites with any other carbon-based matrix. The performance is equally impressive when 0.8CuS:0.2g-C3N4 composite is used as an anode in a sodium ion coin cell and a reversible capacity of 408 mA h g(-1) is obtained at a current rate of 2.0 A g(-1) after a run of 800 cycles. A sodium ion full cell with NVP cathode and 0.8CuS:0.2g-C3N4 composite anode has been fabricated and cycled for 100 runs at a current rate of 0.1 A g(-1). It can be inferred that the g-C3N4 matrix improves the ion transfer properties, alleviates the volume alteration happening in the anode during the discharge/charge process and also helps in preventing the leaching of polysulfides generated during the electrochemical process.

Li-ion batteries with conversion type anode are attractive choice, for electric vehicles and portable electronic devices, because of their high theoretical capacity and cycle stability. On the contrary, enormous volume change during lithiation/delithiation and irreversible conversion reaction limits use of such anodes. To overcome these challenges, incorporating nano-sized SnO (x) on flexible carbonaceous matrix is an efficient approach. A facile and scalable fabrication of SnO nanodisc decorated on SnO2 quantum dots embedded carbon (SnO (x) @C) is reported in the present study. Detailed structural and morphological investigation confirms the successful synthesis of SnO (x) @C composite with 72.3 wt% SnO (x) loading. The CV profiles of the nanocomposite reveal a partial reversibility of conversion reaction for the active materials SnO (x) . Such partial reversible conversion enhances the overall capacity of the nanocomposite. It delivers a very high discharge capacity of 993 mAh g(-1) at current density of 0.05 A g(-1) after 200 cycles; which is 2.6 times higher than that of commercial graphitic anode (372 mAh g(-1)) and very close to the calculated capacity of the SnO (x) @C composite. This unique nanocomposite remarkably improves Li storage performance in terms of reversible capacity, rate capability and cycling performance. It is established that such engineered anode can efficiently reduce the electrode pulverization and in turn make conversion reaction of tin partially reversible.

Lithium-sulfur batteries have been strongly advocated as prominent candidate for the next-generation energy storage device. The shuttling of lithium polysulfide (LiPS) during cycling is inherent problem in these batteries which results in huge capacity fading and impede their practical applications. A simple but effective method is adopted to synthesize polypyrrole coated sulfur nanoparticle which retard the LiPS dissolution in electrolyte. The polypyrrole coated continuous conducting network cathode with nano size (similar to 70 nm) sulfur particle and a stable solid electrolyte interface (SEI) layer protected anode for high performance Li-S battery is demonstrated in this study. Such engineered structure can minimize the fast capacity fading considerably and nano size sulfur makes themselves more accessible to ions and electrons. Strategically, for Li anode protection, LiPS based ternary salt electrolyte (Li2S6, LiNO3 and LiTFSI) is used which form a stable SEI-layer on Li anode during initial cycles. The composite cathode exhibit an initial discharge capacity of 1085 mAh g(-1) at 0.2 Ag-1 current density with a low capacity decay of 0.31% per cycles and cycled up to 165 cycles. The post-mortem analysis validates efficient trapping of LiPS in the cathode side and formation of a stable protective SEI layer on Li anode.

Grinding is a basic physical process, and the grinding tools “mortar and pestle” have been in use since times immemorial. It has been practiced in almost all spheres of human life from kitchen to laboratories as well as in large industrial processes. Chemical synthesis by applying force or the “mechanochemistry” has been employed as a synthetic procedure for a long time but now the need to adopt “greener”, cost-effective and less harmful methods of synthesis has brought back the mechanochemistry to forefront in last decade. It has emerged as the one of the most efficient, advantageous and environmentally benign alternatives to traditional synthesis routes for the preparation of nanomaterials for advanced applications. The features such as ease of operation, simplicity of equipment, high reproducibility, relatively mild reaction conditions and the solvent-free condition (in case of dry milling) have made it the synthesis technique of choice for the synthetic chemist. It is used for synthesizing a wide variety of both single-phasic and composite materials varying from inorganic solids (oxides and non oxides), organic compounds, polymers, metal complexes, metal–organic frameworks. Materials with applications in varied areas such as hydrogen storage materials, energy applications, pharmaceuticals, as well as advanced nanocatalysts have been synthesized using this method. In recent times, the dry grinding or milling has been further modified by addition of a small amount of solvent or polymer, also called liquid-assisted grinding or polymer-assisted grinding that yields different products, speeds up the reaction and also ensures better usage of reactants. The fact that mechanical force or shear is the driving force for the reaction, and it also presents a novel way to obtain hitherto unknown (and interesting) products. The chapter discusses the basics of mechanochemical synthesis along with the above-mentioned points in the details.

In this manuscript, the effect of adding graphitic carbon nitride (g-C3N4) on the electrochemical properties of ZnS conversion alloying anode has been investigated in detail. A cooperative phenomenon is observed in case of the ZnS/g-C3N4 composite anodes both in the lithium-ion and sodium-ion half-cell configuration. The ZnS nanoparticles render high capacity and gets lodged in the g-C3N4 nanosheets synthesized using acid assisted sonication method and leads to a synergistic effect which prevents restacking of layers and agglomeration of nanoparticles. The 0.7ZnS:0.3g-C3N4 composite delivers long term reversible capacity of similar to 596.9 mAh g(-1) after 1150 cycles and similar to 432.6 mAh g(-1) after 750 cycles in Li+/Na+ half-cell configuration, respectively, at a high current density of 1 A g(-1). The structural and electrochemical investigation of the bare ZnS and ZnS/g-C3N4 composite anodes along-with post-mortem SEM and TEM analysis has been discussed. The enhanced rate capability of the 0.7ZnS:0.3g-C3N4 electrode can be attributed to a fairly prominent role played by capacitive charge storage. The deleterious volume alteration effect during the shuttling of Li+/Na+ ions in ZnS is mitigated by the presence of g-C3N4 and it renders a high reversible capacity and initial coulombic efficiency to the composite anodes which has been studied via ex-situ X-ray photoelectron spectroscopy. (C) 2021 Elsevier Ltd. All rights reserved.

New air and moisture stable di-tert-butyltin complexes derived from 2-mercaptopyridine (HSpy), [tBu2Sn(Spy)2], [tBu2Sn(Cl)(Spy)] and 4,6-dimethyl-2-mercaptopyrimidine (HSpymMe2) [tBu2Sn(Cl)(SpymMe2)], have been prepared and utilized as single-source molecular precursors for the preparation of orthorhombic SnS nanoplatelets by a hot injection method and thin films by aerosol assisted chemical vapour deposition (AACVD). The complexes were characterized by NMR (1H, 13C, 119Sn) and elemental analysis and their structures were unambiguously established by the single crystal X-ray diffraction technique. Thermolysis of these complexes in oleylamine (OAm) produced SnS nanoplatelets. The morphologies, elemental compositions, phase purity and crystal structures of the resulting Oam-capped nanoplatelets were determined by electron microscopy (SEM, TEM), energy dispersive X-ray spectroscopy (EDS) and pXRD, while the band gaps of the nanoplatelets were evaluated by diffuse reflectance spectroscopy (DRS) and were blue shifted relative to the bulk material. The morphology and preferential growth of the nanoplatelets were found to be significantly altered by the nature of the molecular precursor employed. The synthesized SnS nanoplatelets were evaluated for their performance as anode material for lithium ion batteries (LIBs). A cell comprised of an SnS electrode could be cycled for 50 cycles. The rate capability of SnS was investigated at different current densities in the range 0.1 to 0.7 A g-1 which revealed that the initial capacity could be regained.

SnO2 quantum dots (QDs) embedded iron oxide (IO) nanocomposite is fabricated and explored as a capable sensor for lead detection. Square wave anodic stripping voltammetry (SWASV) and amperometry have been used to explore the proposed sensor's response towards lead detection. The modified electrode shows linear current response for concentration of lead ranging from 99 nM to 6.6 mu M with limit of detection 0.42 mu M (34 ppb). Amperometry shows a detection limit as low as 0.18 nM (0.015 ppb); which is far below the permissible limit of lead in drinking water by World Health Organization. This proposed sensor shows linear current response (R-2 = 0.98) for the lead concentration ranging from 133 x 10(-9) to 4.4 x 10(-6) M. It also exhibits rapid response time of 12 sec with an ultra high sensitivity of 5.5 mu A/nM. These detection properties promise the use of SnO2 QDs -IO composite for detection of lead in environmental sample with great ease.

An acid-functionalised, magnetic, room-temperature ionic liquid, 1-acyl-3-methylimidazolium tetrachloroferrate ([AcMIm]-FeCl4), was synthesised and its optical, magnetic, and thermal properties were investigated. The magnetic moment (0.05402 emu in 2 T magnetic fields) showed strong paramagnetic behaviour, and thermogravimetric analysis indicated very good thermal stability with a decomposition temperature higher than 230 degrees C. Additionally, [AcMIm] FeCl4 efficiently catalysed the oxidative ipso-hydroxylation of arylboronic acids and regioselective Friedel-Crafts acylation without external organic solvent or additives, such as acids, base, and ligands. This functionalised ionic liquid, [AcMIm]FeCl4, was recycled and reused at least six times without significant loss of its catalytic properties and stability.