DC Glow Discharge Plasma Research Articles

Development of surface-activated La0.6Ca0.4MnO3 perovskite-type electrodes using oxygen plasma for highly stable supercapacitor application

This study introduces a novel and efficient approach for synthesizing perovskite-type nanoparticles and advanced plasma surface activation to significantly improve the supercapacitor's performance. High-purity La0.6Ca0.4MnO3 (LCMO) perovskite nanoparticles with a crystalline structure were synthesized using a facile coprecipitation technique, followed by an innovative low-pressure DC glow-discharge plasma treatment in an oxygen atmosphere. This plasma surface activation process enhances the surface properties of the nanoparticles and boosts their electrochemical performance, representing a transformative modification method for energy storage materials. Detailed analysis of the synthesized and surface-activated LCMO (SA@LCMO) nanoparticles revealed a well-defined cubic morphology with a remarkable surface area of 95 m2/g, as confirmed by TEM and BET analysis. The plasma-treated SA@LCMO electrodes demonstrated superior supercapacitor performance, delivering an impressive specific capacitance of 453 F/g at a current density of 1 A/g more than doubling the 225.8 F/g achieved by untreated LCMO electrodes. Additionally, the SA@LCMO electrodes exhibited exceptional cycle stability, retaining 87 % of their capacitance and achieving a coulombic efficiency of 95.2 % after 10,000 GCD cycles. The material also showed promising energy storage capabilities, with a maximum energy density of 3.92 Wh/kg at a power density of 170.6 W/kg. These results highlight the transformative impact of plasma surface activation on perovskite nanomaterials, positioning the SA@LCMO as a highly promising candidate for next-generation energy storage technologies with superior energy density, durability, and performance. This study introduces new avenues for surface engineering perovskite-based materials to create scalable high-performance energy storage devices.

The Effective Capacitance Behaviour of Argon Plasma Exposed Al Dopped CdO Electrode Used in Efficient Metal ‐Air Batteries

AbstractThe impact of employing DC glow discharge plasma on aluminum‐doped cadmium oxide (Al‐doped CdO) electrodes is explored in the context of advanced energy storage, particularly focusing on Al‐air batteries. Utilizing various characterization techniques including XRD, FTIR, Raman spectroscopy, FESEM, and EDS, we identify significant changes in structure and morphology induced by plasma treatment, such as nano scale clustering, increased surface roughness, and higher oxidation levels. Electrochemical tests with a three‐electrode system shows remarkable improvements in charge storage capacity after plasma treatment, particularly with argon plasma, resulting in increased capacitance (1140 Fg−1), specific capacity (681 mAhg−1), and reduced charge transfer resistance (4.2 Ω), with notable changes in behavior, especially in potassium hydroxide (KOH) electrolyte.

Blend of low cost electrode material for energy storage device under DC glow discharge plasma exposed ESAC

Blend of low cost electrode material for energy storage device under DC glow discharge plasma exposed ESAC

High Porous Activated Carbon Electrode Derived from Watermelon Peel Biomass Exposed with DC Glow Discharge Plasma Applied for Super Capacitors

The growing demand for sustainable and environmentally-friendly technologies has spurred the exploration of innovative methods for waste management and resource utilization. Among the various bio-wastes generated globally, watermelon peel emerges as a significant contributor. To characterize carbon materials in the presence of functional groups, for morphological analysis, and intensity, we subjected activated fruit peel carbon to X-ray diffraction, Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy, X-ray photoelectron spectroscopy, and Raman studies. Furthermore, we examined its electrochemical performance. Another method used to assess wettability is the contact angle. Watermelon-rind-activated carbon was exposed to a DC glow discharge oxygen and air plasma with a 450 V applied potential. The air-treated carbon demonstrated a noteworthy capacitance of 1669 F g−1 at 0.5 mA g−1 in a 2 M KOH electrolyte. Our study found that the properties of the activated carbon were enhanced through cold plasma treatment. This research provides valuable insights into the potential resources of fruit peels and proposes a novel adsorbent with cost-effective advantages in supercapacitors, which could provide effective energy storage for portable gadgets, electric cars, and renewable energy systems, thus presenting a solution for sustainable waste management.

Excellent Diffusive Performance of Cold-Plasma-Exposed Activated Peanut Shell Carbon as an Electrode in Al-Air Batteries

Modern energy and ecological sustainability can be accomplished in part, by using activated bio char-based electrodes made from biomass waste in energy-producing devices like metal-air batteries and fuel cells. Herein, a simple method of combining Pyrolysis graphitization with DC glow discharge plasma is used to create highly disorder carbonaceous materials incorporating surface functional groups from a readily available and inexpensive bio waste of peanut shells. The synthesized activated Peanut shell carbon material displays remarkable supercapacitance performance in 2 M KOH at elevated specific capacitances (537 Fg−1 at 10 mVs−1) and catalytic ability for the oxygen reduction response at a half-wave peak of 0.19 V. Water contact angle and dispersion studies showed a considerable improvement in the surface’s hydrophilic following plasma treatment, and FTIR and Raman spectroscopy were also used to evaluate the surface’s functional group and micro structure. In this study, a simple, affordable, and environmentally friendly method for making activated dis ordered carbon is revealed. It is then investigated as a potential electrode for supercapacitor, metal air battery, fuel cell applications.

Response of the modified GAFCHROMIC EBT2 radiochromic film to DC glow discharge plasma

The response of the modified GAFCHROMIC EBT2 radiochromic film to DC Oxygen glow discharge plasma was investigated using a flatbed scanner and an UV–Vis spectrophotometer. The film was modified by removing the polyester overlaminate, adhesive, and topcoat layers with a total thickness of 80 µm, and is now referred to as EBT2-M. The EBT2-M films were exposed to DC Oxygen plasma for different durations: 0, 0.5, 1, 2, 3, 4, 7, and 10 min. The exposed films exhibit coloration homogeneity with an average variation of (1.6 ± 0.3) × 10−4 pixel values/µm, irrespective of the applied exposure time. The pixel values of the red-and-green channels and weighted grayscale images decreased exponentially with different sensitivity amounts to ∼\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sim$$\\end{document} 39.67, 49.69, and 42.11 min−1, respectively, as the exposure time increased. The two absorption peaks at 580 ± 4 nm and 632 ± 4 nm in the UV–Vis absorption spectra of the exposed GAFCHROMIC EBT2-M radiochromic films are increasing with increasing exposure time up to 4 min, thereafter saturated for prolonged exposure time. The integrated absorbance in the range from 400 to 700 nm is linearly correlated with the exposure time. The indirect and direct optical energy band gaps and Urbach energy of the modified GAFCHROMIC EBT2 film are weakly correlated with the exposure time. These findings suggest the utilization of the modified GAFCHROMIC EBT2 radiochromic film as a novel and simple technique for plasma diagnostics.

Investigation of the temperature of electrons in a glow discharge plasma at direct current Ar and Ar/C2H2

This paper presents the results of the study of the electron temperature in argon and argon-acetylene plasma of DC glow discharge. The optical-emission method was used to determine the main parameter of the complex plasma. The dependence of the electron temperature on the operating pressure, voltage, and discharge time was determined from the intensity of spectral lines. The source voltage was varied from 1 kV to 1.5 kV, and the pressure was maintained between 0.1-1 torr. As a time-dependent function, the electron temperature was calculated every 20 seconds during a 200-second discharge. The results showed that in argon plasma, as the pressure increases, the electron temperature decreases up to a pressure value of 0.4 torr, subsequent increase leads to an increase in temperature. Also, with the increase in source voltage, a decrease in electron temperature within the error limits is observed. In addition, in dust plasma (PECVD in Ar-C2H2), the electron temperature as a function of pressure and source voltage showed a trend similar to that observed in argon plasma. However, the electron temperature in dust plasma increases as a function of time at the initial moment, after which it decreases sharply with time.

Electric field-assisted laser ablation fabrication and assembly of zinc oxide/carbon nanocomposites into hierarchical structures for supercapacitor electrodes.

One of the major challenges in the field of electrochemical energy storage device performance improvement is the development of suitable synthetic materials for electrodes that can provide high power and high energy density features combined with their long-term stability. Here, we have developed a novel two-step approach based on DC glow discharge plasma pre-treatment of a carbon cloth substrate followed by electric field-assisted laser ablation for the synthesis of ZnO/C nanocomposites in a liquid and their simultaneous assembly into hierarchically organized nanostructures onto the pre-processed carbon cloth to produce a supercapacitor electrode. To form such nanostructures, a processed carbon cloth was included in the electrical circuit as a cathode during laser ablation of zinc in water, while a zinc target served as an anode. A series of studies have been performed to explore the structure, morphology, composition and electrochemical characteristics of the synthesized ZnO/C nanocomposites. Application of the external field provided additional possibilities for tuning the particle morphology. The parameters of the obtained nanostructures were shown to depend on the direction of the applied electric field and liquid composition. SEM studies revealed a nanoflower-like morphology of the prepared nanomaterial having potential in supercapacitor applications due to a large surface area. The ZnO/C nanoflowers, deposited onto a carbon cloth substrate, were tested for energy storage by cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) analysis. The results showed a pseudocapacitor behavior with a maximum specific capacitance of about 3045 F g-1 (at a scan rate of 1 mV s-1). These results demonstrate a promising storage efficiency of the synthesized ZnO/C nanocomposite as a material for supercapacitors.

Chemical constitution of coatings deposited remotely by activation of hexamethyldisiloxane in positive column plasma of glow discharge in argon flow

The present work deals with the chemical constitution of coatings deposited by plasma activation of hexamethyldisiloxane in positive column plasma of a low-pressure DC glow discharge in an argon flow (mass flow rate 230 mg/min). X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) are used to analyze deposit chemistry. The substance is complex and consists of many constitutional units forming branched and cross-linked irregular macromolecules. Chemical constitution depends on both discharge current (10–60 mA) and monomer flow rate (1–10 mg/min). Using the specific energy (SE) and Arrhenius-like approach, the threshold energy for the plasma polymerization of HMDSO has been estimated to be 12 ± 1 eV. Two regimes of the plasma chemical system have been identified. At SE near the threshold energy (from 5 to 40 eV/molecule), polymethylsiloxane-like coatings are deposited and variation of SE practically does not lead to changes in chemical constitution, but significantly affects the mass yield of deposit. At specific energies much higher than threshold energy, polymethylhydroxysiloxane-like coatings are formed; the coating structure is strongly SE-dependent, while the mass yield of the deposit does not change.

Dynamic Electrochemical Action of Low Temperature Plasma Exposed NaFePO4/Activated BCC Nanocomposites in Cathode Applications

Abstract In this research, we designed a high performance cathode materials for sodium-ion batteries derived from cold plasma exposed NaFePO4/activated bamboo charcoal (BCC). XRD, FTIR, FESEM, and Brunauer–Emmett–Teller (BET) were used to examine the crystal structure, functional groups, morphological features, and surface area of the composites. The material's surface characteristics, such as wettability, adhesion, and conductivity analysis, were proved, and the energy storage capacity of the material and these characteristics were magnified by exposure to DC glow discharge plasma. In this work, the NaFePO4/activated BCC was subjected to DC glow discharge plasma with various plasma producing gases. The electrochemical investigation shows that the air plasma-treated composite produces the best results when compared to the untreated sample. The enhancement of the diffusivity of the composite reveals that the plasma-treated materials are appropriate for energy storage devices.

Self-excited converging shock structure in a complex plasma medium.

We report the study of a self-excited converging shock structure observed in a complex plasma medium. A high-density dust cloud of melamine formaldehyde particles is created and horizontally confined by a circular ring in a dc glow discharge plasma at a particular discharge voltage and pressure. Later, as the discharge voltage is increased, a circular density crest is spontaneously generated around the outer boundary of the dust cloud. This nonlinear density structure is seen to propagate inward towards the center of the dust cloud. The properties of the excited structure are analyzed and found to follow the characteristics of a converging shock structure. A three-dimensional molecular dynamics simulation has also been performed in which a stable dust cloud is formed and levitated by the balance of forces due to gravity and an external electric field mimicking the cathode sheath electric field in the experiment. Particles are also horizontally confined by an external electric field, representing the sheath electric field of the circular ring present in the experiment. A circular shock structure has been excited by applying an external perturbation in the horizontal electric field around the outer boundary of the dust cloud. The characteristic properties of the shock are analyzed in the simulation and qualitatively compared with the experimental findings. This paper is not only of fundamental interest but has many implications concerning the study of converging shock waves excited in other media for various potential applications.

Simulation of DC glow discharge plasma with free-moving dust particles in the radial direction

A self-consistent fluid model is developed to investigate the radial distributions of dusty plasma parameters in a DC glow discharge, in which the extended fluid approach of plasma particles and the transport equations of dust particles are coupled. The electrical interaction between charged dust particles is considered in the model. The time evolution of radial distributions of dust density, plasma density, the radial component of electric field and the forces acting on dust particles when dust density tends to be stable, are obtained and analyzed under different discharge currents and dust particle radii. It is shown that the dust density structure is determined mainly by the radial electrostatic force, thermophoretic force and ion drag force in the discharge tube, and both discharge current and dust particle radius have an obvious effect on the transport processes of dust particles. The dust particles gather in the central region of the discharge tube for low discharge current and small dust radius, then dust voids are formed and become wider when the discharge current and dust radius increase. The plasma parameters in the dust gathering region are obviously affected by the dust particles due to the charging processes of electrons and ions to the dust surface.

Interplay between electron and ion plasma waves

We report the observation of the interplay between the first kind of high-frequency electron-dominated plasma waves (EPWs) and the second kind of low-frequency ion-dominated plasma waves (IPWs) in a DC glow discharge plasma experiment. On application of positive DC voltage on a probe immersed in plasma when the drift velocity of the electrons (vd) ≈1.3× the thermal velocity of electrons (vte), it gives rise to an instability resulting in the formation of double layers (DL). Under DL conditions, the anode sheath extends deep into plasma. The DL represents a nonequilibrium plasma condition that is known for the instabilities and excitation of plasma waves. In this experiment, the effect of the monotonic increase of plasma density fluctuations (δn≈0.01%) on the evolution of DL has been studied. The interplay between EPWs and IPWs is observed in the course of this investigation. The overall plasma response on density fluctuations is recorded as floating potential fluctuations (FPFs) which vary with an increase of δn. The FPFs exhibit order-chaos-order transition with the evolution of DLs. Further analysis of the fluctuations using the wavelet method gives a spectrum in both the time and frequency domains simultaneously. Wavelet spectra reveal that the nonlinear evolution of FPFs is a consequence of the interplay between EPWs and IPWs due to the trapping and detrapping of electrons in the extended anode sheath region. These results explain that the ordered oscillation corresponds to dominant EPWs and the chaotic fluctuations are due to the coexistence of EPWs and IPWs. This new understanding may assist to study the complex plasma behaviour observed in laboratories as well as space plasmas.

Modification of Child-Langmuir Law for Electrodes of Different Materials and Shapes Using Nitrogen Gas

A dc glow discharge plasma between the planar electrode and planar, conical, and hemispherical electrodes was studied. The electrode materials made of aluminum, graphite, and stainless steel (SS) were used. The experimental results showed a deviation in the traditional Child-Langmuir (CL) law as a result of the use of different shapes and materials of anodes and cathodes. The new parameters of the modified CL law as a function in the surface areas of electrodes, their work function materials, and their contributions to the electrical discharge. The lowest discharge characteristics were for the aluminum planar electrode (anode or cathode) with the aluminum and graphite hemispherical one. The planar aluminum cathode with the conical SS anode gave the highest discharge characteristics. The planar aluminum anode with conical SS cathode had the lowest Paschen curve values. In Paschen curves, the highest values were discovered to be for the planar cathode in a comparison with different cathodes. The hemispherical aluminum anode had the highest Paschen values compared with different anodes. Moreover, the contribution ratio of the anode to the cathode in the discharge for the aluminum planar diode was equal to the ratio between their surface areas and the ratio between their work function materials. In contrast, this contribution ratio for the other discharge cases was equal to the multiplication of the surface areas ratio of the anode to cathode and the ratio of their materials’ work functions. The modified CL law and its coefficient were generalized for the electrodes of different shapes, materials, and used gases.

Phase switching phenomenon in a system of three coupled DC glow discharge plasmas.

We report the first experimental observations of phase switching in a system of three coupled plasma sources. Two of the plasma sources are inductively coupled to each other while the third one is directly coupled to one of them. The coupled system acquires a frequency pulling synchronized state following which a transition occurs to a frequency entrainment state with an increase in the frequency of the directly coupled system. We also observe a sudden jump from a lower to a higher frequency entrainment state and a concomitant phase switching between the oscillations of the two directly coupled sources while the phase difference between the inductively coupled sources remains constant. These experimental findings are established using various diagnostic tools, such as the Fourier spectra, frequency bifurcation plots, Lissajous plots, and Hilbert transforms of the data. The experimental results are qualitatively modeled using three coupled van der Pol equations, in which two of them are environmentally coupled while the third one is directly coupled with one of them.

Plasma immobilization of azobenzene dye on polyamide 6 polymer

Plasma treatment of polymeric materials is a cost-effective and efficient technique to modify the surface and change the constituent unit configuration. This research investigates the effects of argon DC glow discharge plasma on pure and DR1 dye-loaded polyamide 6 polymer films and stabilization of dye on the surface. Plasma breaks some bonds and activates the surface through creating reactive structures such as free radical sites on the surface and increases tertiary amides on the surface of polymer. Besides, this process alters surface topographical characteristics and conformation of azobenzene dye which are effective on the durability of the dye on the surface. Plasma causes interactions of the dye with the polymer and immobilizes the dye on the polymer. On the other hand, these interactions lead to changes in the dye's optical and geometric isomeric activity and stability. This work studies the chemical and morphological changes of polyamide 6 by plasma with AFM and spectroscopic methods. Furthermore, the aging of nylon 6 films loaded with DR1 dye is measured, and the conformational changes of the dye are investigated. Plasma stabilizes the dye on the polymer surface through making changes of chemical and physical properties on the surface components.

Characterization of DC glow discharge plasma in co-axial electrode geometry system by nonlinear dynamical analysis tools

This paper reports plasma behavior in an un-magnetized, co-axial electrode geometry DC glow discharge plasma system. Fluctuations and hysteresis in discharge characteristics have been observed when the electrode system has a central anode configuration. The important fact is that fluctuations and hysteresis in discharge characteristics are not observed in a central cathode configuration. The radial profile of plasma potential shows that it is less than the anode potential, so current continuity is maintained in this current-driven system. This paper also attempts to identify the source of order-to-chaos-to-order in floating potential oscillations with respect to the discharge characteristics. When discharge current (Id) increases after the first negative differential resistance region, the system self-organizes and stabilizes into a state of periodic oscillations. Chaotic behavior is a possible development of new dynamical states in the discharge, which develops from an initial high frequency, low amplitude oscillations (in the range 11.6 mA < Id < 15 mA) and, thereafter, transits to low frequency, large amplitude oscillations at Id >15 mA. In the reverse path of discharge characteristics, the oscillations are more regular than in the forward path. Before the production of low frequency, large amplitude oscillations, the current oscillations follow a similar pattern to the floating potential oscillations. As it transits from chaotic to low frequency, large amplitude floating potential oscillations, discharge current oscillations show a chaotic type of behavior.

Uvećavanje GCD ponašanja kompozita FePO4 sa bambusovim ugljem izloženim plazmi niske temperature, primenjenim u uređajima za skladištenje energije

Materials based on phosphate have been suggested as suitable electrode components for energy storage devices and also indicated that the phosphate framework can help to keep active sites stable. The physical and chemical properties of Fe-based phosphates make them promising cathode compounds for energy storage systems. In this work, the additive carbonous material as a bamboo charcoal (BCC) which was prepared and activated using the pyrolysis process. The irradiation of DC glow discharge plasma improved the surface attributes such as wettability, adhesion, and conductivity. Here, the hydrothermal technique was used to synthesize FePO4 nano particles. The dielectric behaviour was analysed at room temperature for pure FePO4 and composite of FePO4/Plasma treated BCC. The GCD behaviour of pure FePO4 and composite of FePO4/Plasma treated BCC was analysed with aqueous electrolyte of 2M KOH at different current densities. In perspective, the dielectric constant and specific capacitance of the FePO4/plasma treated BCC material seems to be very strong.

Ecofriendly surface modification of cotton fabric to enhance the adhesion of CuO nanoparticles for antibacterial activity

ABSTRACT The present study employs a facile and environmentally cleaner plasma technology to induce adhesion between the cotton fabric and CuO nanoparticles. The oxygen plasma pre-treatment of cotton fabric was performed using DC glow discharge plasma for different plasma treatment times (5, 10 and 15 min) with constant pressure and power. The untreated and plasma treated cotton fabrics were analysed by contact angle, AFM, XPS, XRD, FESEM and elemental mapping analysis. From the AFM results, it is observed that the surface roughness of treated fabric increases with plasma treatment time. XPS analysis reveals that the oxygen plasma treatment introduces oxygen-rich functional groups on the surface which provides the adhesion property of cotton fabric. The 15 min oxygen plasma treated cotton fabric is optimised to coat the CuO nanoparticles based on the AFM and XPS analyses. Furthermore, the CuO nanoparticles coated plasma treated cotton fabric are analysed for antibacterial test and a significant antibacterial activity was identified for gram-positive and gram-negative bacteria.

Impact of DC glow discharge plasma treated Ti doped hydroxyapatite nanomaterials using antibacterial and cytotoxicity applications

In this work we developed Ti doped hydroxyapatite with were synthesized by using a solgel technique with exposed to DC glow discharge plasma with different times treated. The pure and Ti/HAp were characterised by using different characterizations like XRD, FTIR, SEM, EDAX, UV-visible, PL, TG-DTA, antibacterial activity, 3T3 fibroblast cells and MCF-7 breast cancer cell line with cytotoxity efficiency analysis. The pure HAp and Ti/HAp materials had a nanocube and nanoflakee shape in the SEM results. In the ultraviolet-visible light (UV-vis) spectrum, the band edge absorption of bare HAp and Ti/HAp samples is discovered at wavelengths of 295 nm and 328 nm, respectively. The antibacterial activity of untreated and plasma-treated pure HAP and Ti/HAp samples are tested against two gram-positive bacteria, Bacillus cereus and Staphylococcus aureus, as well as two gram-negative bacteria, E. coli and Pseudomonas aeruginosa, using the agar well diffusion technique. The MTT assay was used to investigate the mean per cent (% percent) cell survival of Ti/HAp at various concentrations (6 mg/mL; 85 mg/mL) against 3T3 fibroblast cells and human MCF-7 Breast cancer cell lines. The synthesised Ti/HAp biocompatibility makes it a viable contender for future biological uses.