Sulfidation Behavior Research Articles

Influence of chain entanglements and melt memory effect on the crystallization behavior of polyphenylene sulfide

Polyphenylene sulfide (PPS) has a prospective application in high-frequency communication due to its excellent dielectric properties. However, owing to the strong melt memory effect, the crystalline structure of PPS is very sensitive to the processing conditions and difficult to be controlled. To date, the melt memory effect of polymer cannot be detected directly and quantitatively. In this work, four PPS samples were successively prepared via polymerization, extrusion and dissolution treatment. The Fourier infrared transform spectroscopy (FTIR), high-temperature gel permeation chromatography (HT-GPC) and dynamic rheological tests disclose that these four PPS samples have analogous molecular structure and only differ in entanglement density. The molecular weight between entanglements (Me) decreases gradually from 1188 to 354 g/mol. Furthermore, differential scanning calorimetry (DSC) and polarized optical microscopy (POM) measurements were carried out to study the effect of entanglement density on the crystallization kinetics of PPS. It is found that entanglement density is a key indicator to characterize the melt memory effect of PPS semi-quantitatively, and the residual local ordered structures in PPS melt is proportional to Me. In addition, the crystallization kinetics of PPS is determined by the cooperation of melt memory effect (nucleation) and entanglement density (growth). Accordingly, the relationship of “chain entanglements” → “melt memory effect” → “crystallization behavior” of PPS is established, constructing a roadmap for the precise control of crystalline structures of PPS products during practical processing.

CuS as Unique Cathode Material for Li Solid-State Batteries: Properties, Reaction Mechanism and Tomography

Copper sulfide (CuS) is a naturally occurring mineral that reacts with lithium via a conversion reaction to form Li2S and Cu. The theoretical energy density of the reaction is 961 Wh/kg, the theoretical cell voltage is 1.96 V. Among all the conversion reactions, copper sulfide shows a unique behavior as large, µm-sized copper crystallites are formed during discharge. Some years ago, it was shown that the reaction can proceed reversibly in suitable electrolytes.[1] This presentation will discuss the behavior of copper sulfide as a cathode material in solid state batteries. In this context, the low cell voltage allows the use of Li3PS4 as a solid electrolyte, which is a major advantage. Despite the large volume expansion (+74%), the material can be cycled in solid state batteries at high contents (70 wt%), again forming large copper crystallites.[2] The size of the crystallites allows the reaction to be studied by 3D X-ray tomography.[3] In addition to phase transformations, crack formation can also be observed. The latter is strongly pressure dependent and can be minimized by increasing the pressure.[1] Birte Jache, Boris Mogwitz, Franziska Klein, Philipp Adelhelm (2014) Copper sulfides for rechargeable lithium batteries: Linking cycling stability to electrolyte composition Journal of Power Sources 247: 703-711.[2] Aggunda L Santhosha, N Nazer, Raimund Koerver, Simon Randau, Felix H Richter, Dominik A Weber, Joern Kulisch, Torben Adermann, Jürgen Janek, Philipp Adelhelm (2020) Macroscopic displacement reaction of copper sulfide in lithium solid-state batteries Advanced Energy Materials 2002394: .[3] Zhenggang Zhang, Kang Dong, Katherine A Mazzio, André Hilger, Henning Markötter, Fabian Wilde, Tobias Heinemann, Ingo Manke, Philipp Adelhelm (2022) Phase Transformation and Microstructural Evolution of CuS Electrodes in Solid-State Batteries Probed by in-situ 3D X-ray Tomography Advanced Energy Materials 2203143. Figure 1

Ab Initio Molecular Dynamics Simulations of Amorphous Metal-Polysulfides as Cathode Materials for Lithium-Ion Batteries

Lithium-sulfur batteries offer a few advantages, including high energy density and low cost, compared to our current battery technology. However, various polysulfide intermediates formed during charging and discharging lead to the polysulfide shuttle effect, which hinders their commercial application. It has been shown that amorphous metal sulfides can reduce the formation of polysulfides, although a fundamental understanding is lacking. In this research, amorphous molybdenum and titanium sulfides with different sulfur concentrations were generated by the simulated melt-quench process using ab initio molecular dynamics simulations. Different numbers of lithium ions were added at the cathode/electrolyte interface to simulate the electrochemical conversion process in these materials. It is observed that the behavior of amorphous metal sulfides is different from that of sulfur, and the formation and diffusion of lithium polysulfides have been greatly reduced. Insights obtained from this work could help to develop new strategies to effectively inhibit the polysulfide shuttle effect.

A sensitive voltammetric and density functional theory calculations analysis for the direct interaction of sulfide ion with the multiwalled carbon nanotube

A sensitive and simple cyclic voltametric method was investigated for the direct electrochemical determination of sulfide using multiwalled carbon nanotube paste electrode (MWCNTPE). The sulfide exhibited a distinct and remarkable direct oxidation peak at about 0.56 V in a solution containing sodium chloride as a suitable supporting electrolyte. The effect of voltametric behavior of sulfide was also studied in various supporting electrolyte. Among this sodium chloride containing solution showed a well-defined oxidation peak current as compared to the other supporting electrolyte. The direct oxidation behavior of sulfide in sodium chloride solution was mainly attributed to the less hindrance effect of the electrolyte anions on the surface of electrode. Under optimized condition the oxidation peak current values were found to increase in a linear way with increasing sulfide concentration in the range from 1 × 10−7 to 3 × 10−5 M (R2 = 0.9985). The detection limit (DL) was calculated to be 4 × 10−8 M for the sulfide concentrations. The developed method showed excellent selectivity towards the voltametric determination of sulfide as compared to other competing ions like Br−, NO3−, F−, PO43−, NO2−, I−, CH3COO− present in the solution. Moreover, the method demonstrated good and reproducible results with relative standard deviation (RSD) of 3.8% after 40 successive measurements. The method was successfully applied for determination of sulfide in local tap water samples without any matrix effect. Meanwhile to support the voltametric behavior of sulfide, density functional theory (DFT) calculations were performed at ωB97XD/6-31G(d,p) level of theory to get deep insight into the electronic properties of MWCNT and adsorbed analytes (sulfide) using Gaussian 09 package. The highest interaction energy and the decrease in energy gap of multiwall carbon nanotube with sulfide (MWCNT-S2-) complex are consistent with the highest sensing behavior of MWCNT towards sulfide ion in experimental results.

Reaction behavior of sulfides in blast furnace raw materials under hydrogen-rich reducing atmosphere

Understanding the transformation behavior of sulfides in the blast furnace raw materials during the ironmaking process is crucial for controlling the form and emission of gaseous sulfides in the blast furnace top gas. This study investigates the reactions of coke and sinter at different reducing atmosphere ranging from 200 °C to 1000 °C by using of thermogravimetry and mass spectrometry (TG-MS). Additionally, thermodynamic theoretical calculations were performed to enhance the understanding of the reaction behavior. The results showed that the mixed sinter and coke started to generate H2S at 100 °C under the mixed H2-CO atmosphere and reached the peak between 350 and 400 °C. With the increase of H2 concentration, the peak temperature of H2S generation initially decreased and then increased, with the lowest peak temperature observed under a 50% H2-50% CO atmosphere. Furthermore, COS generation started around 300 °C and reached its peak at approximately 800 °C. The peak content of COS generation increased as the CO concentration. Low temperatures favored the generation of H2S from the mixed sinter and coke, while high temperatures were conducive to the generation of COS.

Effect of K/Na ratio on adsorption of sweetened gas in dehydration packed bed adsorber: A Monte Carlo simulation study of single and multicomponent gas mixture

The input feed of natural gas dehydration units often contains significant quantities of mercaptan. To effectively separate water from the sweet gas stream, it is crucial to select an appropriate molecular sieve. Mercaptan adsorption can cause issues in later stages of the process. In this research, the Grand Canonical Monte Carlo (GCMC) method was employed to investigate the adsorption behavior of methane, ethane, water, methyl mercaptan, and carbonyl sulfide as both single and multicomponent gas mixtures on LTA zeolite with varying K/Na ratios. The obtained data were modeled using the Langmuir and Sips models, with the Sips model exhibiting better agreement with the simulation results. Gas adsorption simulations were conducted across temperatures of 323 K, 313 K, 303 K, and 333 K, a pressure range of 1–70 bar. The findings indicate that increasing temperature diminishes adsorption on LTA zeolite, while increasing pressure has an incremental effect on adsorption. Adsorption studies were performed for both wet and dry gas mixtures. A rise in the number of potassium ions within the zeolite structure resulted in decreased component adsorption, potentially due to the reduction in zeolite cavity size. The results emphasize that the sodium-to-potassium ratio plays a crucial role in mercaptan adsorption or depletion within the packed bed tower. For a gas mixture, it is not recommended to utilize LTA zeolite with a potassium content lower than 55% for gas adsorption due to its propensity to adsorb mercaptan.

Dissolution of anthropogenic and natural hydrogen sulfide in deep-ocean conditions

ABSTRACT Natural and anthropogenic event information helped to simulate the physical–chemical behavior of hydrogen sulfide (H2S) in a deep oil spill and a hypothetical deep-ocean hydrothermal discharge. This research led to the development of the Lagrangian model of the discharge plumes in both cases and also analyzed the profiles of the H2S concentration at different depths taking into account its dissolution in ocean water and oceanographic conditions, such as thermohaline stratification, current fields, as well as the characteristics of the spilled hydrocarbon and the hydrothermal. The results revealed a first approximation in the identification of the dynamic behavior of the concentration profiles of H2S as a function of the oceanographic conditions. Hydrogen sulfide concentrations vary between natural and anthropogenic discharges at various depths, leading to a numerical model for applying in chemical oceanography.

Three dimensional hollow sulphide nanocomposites for supercapacitor electrodes

The transition metal sulphides have gained sufficient attraction due to their high theoretical capacitance, low electronegativity, good thermal and electrical conductivity and good redox behaviour. In the present work, nanocomposites of nickel cobalt sulphide (NiCoS), zinc cobalt sulphide (ZnCoS), copper cobalt sulphide (CuCoS) and nickel-zinc-copper cobalt sulphide (NiZnCuCoS) have been prepared, by hydrothermal synthesis method, for their use as the supercapacitor electrode material. The X-ray diffraction analysis, Field Emission Scanning Electron Microscopy images and UV–Visible studies suggest the formation of quantum dots (as the crystallite size is in the range of 3.5 nm–6.0 nm) in all the nanocomposites. The aim of this study is to observe the change in the electrochemical properties of the transition metal sulphides by multi-metal doping. The electrochemical measurements reveal that among all the prepared nanocomposites, highest specific capacitance (150 F g−1 at 5 mV s−1) has been exhibited by CuCoS nanocomposites (nanowires like structure) whereas highest potential window (1.7 V) and hence highest energy density (16.5 W h kg−1 at 0.1 A g−1) has been exhibited by NiZnCuCoS nanocomposites. Presently, the main goal of supercapacitors is to provide high energy density. It is observed that multi-metal sulphides (NiZnCuCoS), when used as the supercapacitor electrode, provide better electrochemical performance which may be owing to the specific nanosheets like structures as well as good synergism between Ni, Zn, Cu and Co transition metals. Hence it is observed that by multi-metal doping, the supercapacitive behaviour of transition metal sulphides has improved.

One-pot synthesis of CIS nano-particles and their EMI shielding studies

EMI Shielding behaviour of copper indium sulphide (CIS) nanoparticles synthesized by single-step method is presented. 1-Octadecene and oleic acid both play important role in the synthesis, however, presence of oleylamine leads to formation of phase pure CIS as confirmed by XRD. It is observed that incorporation of silver nanoparticles in 1:1 amount with respect to CIS, dramatically enhanced the shielding efficiency from about −3 dB to about −13.5 dB (average) of the CIS/PVA (0.5:1 w/w) composite in X-band. This is possibly the first study of CIS for EMI application.

Experimental and Machine Learning Studies on Chitosan-Polyacrylamide Copolymers for Selective Separation of Metal Sulfides in the Froth Flotation Process

The froth flotation process is extensively used for the selective separation of valuable base metal sulfides from uneconomic associated minerals. However, in this complex multiphase process, various parameters need to be optimized to ensure separation selectivity and peak performance. In this study, two machine learning (ML) models, artificial neural network (ANN) and random forests (RF), were used to predict the efficiency of in-house synthesized chitosan-polyacrylamide copolymers (C-PAMs) in the depression of iron sulfide minerals (i.e., pyrite) while valuable base metal sulfides (i.e., galena and chalcopyrite) were floated using nine flotation variables as inputs to the models. The prediction performance of the models was rigorously evaluated based on the coefficient of determination (R2) and the root-mean-square error (RMSE). The results showed that the RF model was able to produce high-fidelity predictions of the depression of pyrite once thoroughly trained as compared to ANN. With the RF model, the overall R2 and RMSE values were 0.88 and 4.38 for the training phase, respectively, and R2 of 0.90 and RMSE of 3.78 for the testing phase. As for the ANN, during the training phase, the overall R2 and RMSE were 0.76 and 4.75, respectively, and during the testing phase, the R2 and RMSE were 0.65 and 5.42, respectively. Additionally, fundamental investigations on the surface chemistry of C-PAMs at the mineral–water interface were conducted to give fundamental insights into the behavior of different metal sulfides during the flotation process. C-PAM was found to strongly adsorb on pyrite as compared to galena and chalcopyrite through zeta potential, X-ray photoelectron spectroscopy (XPS), and adsorption density measurements. XPS tests suggested that the adsorption mechanism of C-PAM on pyrite was through chemisorption of the amine and amide groups of the polymer.

Biosynthesis, behavior and fate of volatile organic sulfide in Lentinus edodes (Berk.) upon hot-air drying treatment

This study elucidated the biosynthesis and changing behaviors of organic sulfide in shiitake mushrooms upon hot-air drying treatment. The changes of aw, moisture migration, contours of taste and flavor, organic sulfide, and 4 key enzyme activities were monitored throughout three drying procedures (CT/ST1/ST2). Results showed that drying rate was related to the moisture migration. Key enzymes of γ-GTase, ASFase and CS lyase were heat-resistant proteases, while C-Dase exhibited low thermal stability with the activity decreased during treatment. A total of 17 organic sulfides were identified and PLS analyses suggested 6 cyclic polysulfides were formed by C-Dase desulfurization, while 5 thioethers generation were related to the thermal cleavage of direct precursors (straight-chain di/tris/tetrasulfonyl esters) and Maillard reaction. These results indicated that ST2 drying procedures had a positive effect on the formation of cyclic polysulfides at the end of drying pried and the achievement of premium flavor qualities.

In situ observation of the promoting effect of H2S on the formation of efficient MoS2 catalyst for CH4/CO2 reforming

A small amount of H2S exists in natural gas, which can poison and deactivate metal and metal oxide catalysts. MoS2 is a widely used sulfur-tolerant catalyst, and when it is used for natural gas utilization, desulfurization is not required. Herein, Mo sources were impregnated onto Al2O3 with different morphologies and then applied for the CH4/CO2/H2S reforming reaction. By means of XRD, H2-TPR, 27Al MAS NMR, XPS, Raman, TEM etc. characterization methods, we found that in situ introduced H2S into the CH4/CO2 reforming reaction accelerated formation of MoS2 and its full sulfuration on the catalyst, decreased the stacking of MoS2 layer, and obtained more unsaturated Mo sites, therefore further improving the catalytic reactivity by >10%. Moreover, the differences such as phase structure, sulfidation behavior as well as performance among the catalysts were investigated. This provides a new opportunity for effective catalytic utilization of natural gas and the in situ preparation of few-layer MoS2 catalyst.

Synthesis and characterization of mesoporous vanadium sulfides as environmental catalysts for the cycloaddition of CO2 with 2-(phenoxymethyl)oxirane) and oxidation reactions

Metal sulfide is a vital species of compound semiconductor materials, whose metallic ions are in mono-, bi-, or maybe in multi-form. Considering such materials, layered transition metal sulfide (LTMS) including layered transition metal dichalcogenides (LTMDs) like VS2 and VS4 (also called patronite mineral) has attracted growing interest. Moreover, it can be regarded as graphene analogs due to its large interlayer spacing and high theoretical specific capacity, enabling such materials to be applied in different fields i.e. photoelectric staffs, electro-catalysis phenomena, Li-containing batteries, and energy storage usages. Herein, a practical synthetic protocol is designated to construct mesoporous vanadium sulfides (VS2 and VS4) with controlled morphologies from VS2 (Flower-like), VS4 (Urchin-like), VS4 (Microsphere), and VS2 (Nanosheet assemblies) via adjusting the molar ratio of vanadium acetylacetonate and L-cysteine using a one-step solvothermal method. The catalytic activity of vanadium sulfides as an environmental catalyst has been considered for cycloaddition reaction of CO2 and 2-(phenoxymethyl)oxirane), oxidation of dibenzyl sulfide, and 1-phenylethan-1-ol. The prepared mesoporous vanadium sulfides have a higher surface area than the previously reported ones. The results and analysis revealed that the catalytic behavior of vanadium sulfides significantly depends on physical features such as morphology and specific surface area. The structure of the prepared materials was studied using a variety of characterization techniques: FTIR, XRD, TGA, BET, FE-SEM, EDX, and X-ray mapping

Mechanistic scrutinizing the charge storage phenomena of battery-grade Mn-Co-S electrodes

To accelerate the performance of supercapacitors, it is necessary to discover a new class of material with high energy density and redox stability. In this article, we have reported the electrochemical charge storage behavior of binary cobalt manganese sulfides Mn-Co-S (MCS) based binder-free electrodes, which were synthesized thru a facile one-step electrodeposition technique for supercapacitors. We have analyzed the structure and electrochemical properties by Scanning Electron Microscope (SEM), Cyclic Voltammetry (CV), Galvanostatic Charge Discharge (GCD), and Electrochemical Impedance Spectroscopy (EIS). The charge storage nature of the MCS electrodes were scrutinized by applying Power law and Dunn's model to the experimental data. Extracted b-values and dominated diffusive contribution in total specific capacity reveal that MCS has battery-grade nature with high redox reactions stability and capacity. The outcomes suggested that MCS-based electrodes are an appropriate candidate for enhancing the energy density along with the redox reaction stability of asymmetric supercapacitors.

Tracking combustion behavior of copper monosulfide, ferrous sulfide, and chalcopyrite tablets by high-speed microscopic videography

A new suspended-combustion-test method involving high-speed digital microscopy and thermal measurements was developed to analyze small tablets of CuS, FeS, and CuFeS2 to elucidate their combustion behavior and phase changes in flash smelting. Moreover, the frequency of splash generation and homogeneous oxidation of the released gaseous sulfur from each sulfide were monitored. Microstructural analysis of quenched samples by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy revealed that the combustion intensity could be related to the formation of an oxide layer, which blocked the O2 supply to the sample interior. Moreover, the gas formed at various oxygen concentrations agitated the samples. In particular, the generated solid-oxide shell could move, the sulfide was exposed to the surface again, and the combustion reaction proceeded further. Insufficient agitation at lower O2 concentrations resulted in a thick and dense oxide layer, which blocked the O2 supply and caused extinction.

Competition of memory effect and thermal degradation on the crystallization behavior of polyphenylene sulfide

Polyphenylene sulfide (PPS) is one of most widely used special engineering plastics in the world. However, owing to the unique memory effect and thermal degradation effect, the crystalline structure of PPS is extremely difficult to control during the practical processing, resulting in the deterioration of processability and performance of PPS products. In this work, the differential scanning calorimetry (DSC), polarized optical microscopy (POM), in-situ X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and rheological tests were carried out to distinguish these two effects on the crystallization behavior of PPS systematically. It is found that the memory effect and thermal degradation compete “as one falls, another rises” on the crystallization behavior of PPS, both of which accelerate the crystallization rate and reduce the uniformity of crystalline structure. The residual of local ordered structures in PPS melt increases the nucleation rate significantly and could be eliminated as the pre-treatment temperature (Tp) reaches 350 °C. Nevertheless, the chain scission reaction is activated and dominates the crystallization process of PPS when Tp is higher than 350 °C, leading to the notable promotion of crystal growth rate. Accordingly, processing around the transition temperature can minimize the cooperation of melt memory and thermal degradation on the crystallization behavior of PPS, resulting in the lowest crystallization rate and the most uniform crystal size distribution.

The Effect of Corrosion Conditions on Aging of Artificial Patina on Three Bronzes

The new bronze objects of art are almost always patinated before their exposure outdoors or indoors. Among the many patination methods used by practitioners, sulphide patination is one of the most common techniques. The aim of this work is to examine the corrosion behaviour of sulphide patinated bronzes under various aging conditions, including continuous immersion in simulated urban rain, alternating wet/dry cycles, and exposure to corrosion chamber with NO2 gas. The study was conducted on three types of bronzes with varying tin content. Corrosion characterisation of patinated bronze samples was performed by the means of electrochemical impedance spectroscopy and polarization measurements. Chemical composition and morphology of sulphide patinated bronze surface was examined by infrared spectroscopy and scanning electron microscopy. Obtained results show that freshly patinated bronze surfaces exhibit low corrosion resistance that gradually improves over time. An increase in corrosion resistance strongly depends on aging conditions, and it appears to be the highest under continuous immersion conditions.

Electrochemical Separation of Ag2S and Cu2S from Molten Sulfide Electrolyte

The production of precious metals from Cu-rich sources such as ore products or secondary sources is slow and complex largely due to limited solubility in aqueous electrolytes. This results in sequential processing with various electrolytes and chemistries, where first Cu is electrorefined, followed by Ag, followed by Au and the platinum group metals. These are separate processes, often conducted in separate electrorefining and electrowinning facilities. The chemical properties of molten sulfides, and their ability to operate at a temperature where liquid metal cathodes are used, suggest the possibility of an alternative, streamlined processing route for Cu and precious metals. Unfortunately, little thermodynamic or electrochemical information is available regarding the behavior of Cu and precious metal sulfides in molten sulfide electrolytes. Herein, the relative activity of the Cu2S-Ag2S pseudobinary dissolved in a BaS-La2S3 supporting electrolyte is measured at 1523 K. It was found that the supporting electrolyte favors mixing with Ag2S over Cu2S. Molten sulfide electrolysis of Cu and Ag was conducted, with results in good agreement with the thermodynamic model. It is found that the Ag-Cu cathode chemistry will influence the electrochemical selectivity in the Ag-Cu-Ba-La-S system.

Differential Behavior of Metal Sulfides in Hydrothermal Plumes and Diffuse Flows

Extensive sampling of high-temperature hydrothermal fluids and diffuse flows within <2 m of the vent orifices at the 9°50′N East Pacific Rise (EPR) hydrothermal vent field reveals formation of nanoparticulate phases and rapid precipitation/aggregation of metal sulfide minerals upon mixing of vent fluid with ambient seawater. Here, we characterize metal sulfide phases via scanning and transmission electron microscopy (SEM, TEM) in addition to quantifying the concentrations of major and trace metals in filtered and unfiltered fluid samples. Analyses demonstrate that, despite coprecipitation in phases such as chalcopyrite, iron speciation and transport is decoupled from that of copper and zinc. We observe the formation of ∼10–500 nm diameter (nano)particulate Zn and Cu sulfide phases that are near-quantitatively removed by filtration. Iron sulfides, conversely, are typically present in SEM images as larger particles up to tens of microns in diameter. Few small nanoparticles (20–100 nm diameter) are captured on the filter, but determination of nitric-acid-soluble iron in 0.2 μm filtered samples indicates the presence of pyrite nanoparticles. Physical mixing and temperature play a larger role in determining the extent of nanoparticulate pyrite formation than fluid chemistry. In diffuse flow environments, Fe and Cu more commonly co-occur as aggregates of very small crystallites, with the Zn sulfide phases occurring separately. Sample pH and the ZPC (zero point of charge) of metal sulfides exhibit chemical control on nanoparticle and large particle formation versus aggregation. The concentrations of the additional trace metals analyzed vary between vent sites, despite the short distances between the sites and likely similar magmatic sources. Measured trace metal concentrations highlight the importance of diffuse flow systems in hydrothermal metal emissions. These near-vent behavioral differences have implications for the long-distance transport of metals away from vent fields in buoyant and nonbuoyant plumes.

Microwave absorption and dielectric behavior of lead sulfide – graphene composite nanostructure embedded polyvinylidinedilfuoride thin films

A lightweight and flexible microwave absorbing composite of polyvinyledine difluoride (PVDF) was fabricated by loading PbS nanocubes embedded Graphene hybrid nanostructures into the PVDF matrix. The PbS embedded graphene nanosheets (PbS/GNs) are synthesized by hydrothermal technique. The PXRD pattern of the PbS, GNS and PbS/GNS suggested face-centered cubic structured PbS loaded GNS nanosheets. FE-SEM images of the graphene-bound lead sulfide octahedral nanocubes are found to have a size of 100 nm and are unvaryingly distributed on the surface of graphene nanosheets. HRTEM image of graphene surface image showing sheet-like structure is embedded with PbS nanocrystals. The PbS/GNs in PVDF matrix were found to exhibit enhanced dielectric constant, reduction in resistivity, and electrical conductivity. The high dielectric constant was exhibited by the 4% GNs dispersed PVDF with a value of 3.7x105 and 6% GNs/PbS dispersed PVDF showed 3.5 x105 at 1 MHz. The composite PbS/GNs into PVDF exhibit the maximum reflection loss dips in frequency band X for the PbS/Gra/PVDF samples. It is apparent that there are three absorption peaks in the region of 9–12 GHz in which the absorption of −6.9 dB is observed at 10 GHz.