Non-thermal Dielectric Barrier Discharge Research Articles

Investigating the efficacy of non-thermal plasma in the inactivation of cyanobacteria Dolichospermum sp.

Cyanobacteria bloom has been recognized as a serious problem worldwide that requires urgent monitoring and treatment. This study assessed the inactivation of cyanobacteria Dolichospermum sp cells using non-thermal dielectric barrier discharge plasma system under different operational conditions of input wattage and contact time. Both instant and long-term inactivation efficiencies (up to 92.6%) of Dolichospermum sp cells were obtained after plasma treatment regardless the conditions applied. Increased contact time resulted in enhanced inactivation efficiency, while the impact of input wattage was minor. Further investigation was done by analyzing cell morphology, revealing severe deformation of the Dolichospermum sp cell surface due to plasma treatment. The results from this study confirmed the potential of non-thermal plasma in cyanobacteria inactivation which shape the direction for further studies.

Chemical modification of selenium-containing amino acids caused by non-thermal dielectric-barrier discharge atmospheric-pressure plasma.

Since non-thermal atmospheric-pressure ("cold") plasma sources, such as the dielectric-barrier discharge (DBD), have appeared to be remarkably active in wound healing medicine, the elucidation of cold plasma safety and possible secondary undesirable effects becomes of paramount importance. Selenium-containing amino acids, which are commonly incorporated in many enzymes, came in the spotlight for elucidating the plasma impact as easily oxidizable natural targets. The scope of this study was to analyse the impact of non-thermal plasma on selenium-containing amino acids. Moreover, this research examines the emerging role of metals in the context of oxidation potency of reactive species generated by plasma. The dielectric barrier discharge (DBD) was used to treat 4 mM solutions of Se-(methyl)seleno-l-cysteine (1), l-selenomethionine (2) and seleno-l-cystine (3) for varying treatment times to investigate possible degradation products. In this study we used two redox active iron complexes as well as a redox inert zinc complex in order to compare their capacity to affect chemical modifications caused by plasma. The solutions with selenium-containing amino acids after plasma treatment were analyzed by IR spectroscopy, electrospray ionization mass spectrometry (ESI-MS) and High Performance Liquid Chromatography (HPLC). Several oxidation products were observed as a consequence of plasma treatment, namely: Se-(methyl)seleno-l-cysteine (1) and l-selenomethionine (2) were oxidized to selenoxide and selendioxide derivatives, wheres the Se-Se dimer, seleno-l-cystine (3), was converted to Se-cysteine and seleninic acid. Additionally and to our surprise, redox active iron(ii) and iron(iii) complexes as well as the non-redox active zinc(ii) complex caused the same oxidation pattern when added to the plasma treatment mixtures. Finally, a comparison of the results from Se-containing amino acids with those of their S-containing counterparts revealed that Se-containing amino acids are less prone to cold plasma oxidation than S-containing molecules. By elucidating molecular details of plasma-biomolecule interactions herein we aim to contribute to a better understanding of the complex beneficial medical effects of cold plasma treatments.

Impact of Nonthermal Plasma Treatment on the Oxidation of Lipids with Different Unsaturation Degrees.

Nonthermal plasma (NTP) treatment of food presents a new technology for the industry but raises concerns about lipid oxidation due to the presence of reactive species. Considering the critical role of the degree of unsaturation in lipid oxidation, this study investigates NTP-induced oxidation across various unsaturated lipids. These lipids are six oil samples primarily containing one of the following methylesters: oleate, linoleate, linolenate, arachidonate, eicosapentaenoate, and docosahexaenoate. Samples were treated with a nonthermal surface dielectric barrier discharge. Plasma-induced effects were first examined by classical lipid oxidation indicators, such as the peroxide value and p-anisidine value. The specific volatile oxidation products, including hexanal, nonanal, trans-2-hexenal, and methyl 9-oxononanoate, were determined to further elucidate the impact of ozone-related oxidation. Monitoring the production of selected nonvolatile oxidation products, such as epoxy-, oxo-, and hydroxy fatty acid methylesters, confirmed that plasma treatment facilitated the decomposition of lipid hydroperoxide. Generally, the level of plasma-induced oxidation increased in parallel with the unsaturation degree of the studied samples, except for the quantity of individual volatile carbonyls. The long-term effect of NTP treatment was investigated by a stability test, revealing that the oxidative stability depended on the input gas of plasma treatment, the sensitivity of the treated sample, and the presence of antioxidants. Except for the focus on the NTP impact, this study offered a case study of a comprehensive investigation into lipid oxidation.

Enhancing Selectivity with Molecularly Imprinted Polymers via Non-Thermal Dielectric Barrier Discharge Plasma.

Molecularly imprinted polymers (MIPs) are synthetic polymers that mimic the functions of antibodies. Though MIPs are promising tools in various areas, achieving high selectivity in MIPs can be difficult. To improve selectivity, various approaches have been implemented; however, the role of polymerization methods or synthetic techniques in enhancing the selectivity of MIPs has not been studied and remains a crucial area for further research. MIPs are typically prepared from free radical reactions. Recently, we found that Dielectric Barrier Discharge (DBD) plasma can be used to initiate the polymerization of vinyl monomers. The DBD plasma method allows the monomers to associate with the template molecules and initiate polymerization with minimal disruption to the positioning of the monomers. We hypothesize that this could be a preferred method to prepare MIPs over the traditional radical reaction that may cause a disturbance of the pre-associated monomers on the templates for the polymerization. Chicken egg white serum albumin (CESA) was used as the template protein for the MIPs. Our results show that in all test conditions, approximately twofold improvement in selectivity was achieved, which is the primary performance metric for MIPs. This enhancement was evident across all categories, including MIPs prepared from various monomer combinations.

Effects of Non-Thermal Dielectric Barrier Discharge Plasma on Human Fibroblasts: A Narrative Review.

Objectives: Fibroblasts are among the most critical connective tissue cells in almost all tissues and organs. Enhancement of fibroblast differentiation, proliferation, and morphogenesis is of paramount importance in tissue regeneration and wound healing. The non-thermal dielectric barrier discharge (DBD) plasma technology has recently gained interest due to its extensive applications and multiple biological effects. This review article outlines the applications of DBD plasma in dentistry, and its biological effects on human fibroblasts. Materials and Methods: Relevant keywords were searched in PubMed, Ovid, and Google Scholar online databases. The search strategy resulted in selection of 7 studies according to the eligibility criteria. Results: Most studies reported increased cell proliferation and viability after the application of DBD plasma. Four studies that focused on the development of adhesion-related appendages examined the morphology of fibroblast cells, including the creation of vinculin, protrusion, and actin cytoskeleton. Expression of cyclin D1/P27 genes and genes associated with adhesion and cell attachments was also reported in two studies. Conclusion: This narrative review discussed the effects of DBD plasma technology on proliferation and behavior of human fibroblasts, and reviewed the available articles in this regard. More in vivo studies are required to understand the exact effects of this emerging technology on human mesenchymal tissues.

Efficient degradation of p-nitrophenol from water by enhancing dielectric barrier discharge (DBD) plasma through ozone circulation: Optimization, kinetics and mechanism

Non-thermal dielectric barrier discharge (DBD) plasma has received great attention for degradation of persistent organic pollutants such as p-nitrophenol (PNP). However, the feasibility of the DBD implementation is not clear due to its high energy consumption and relatively low degradation efficiency. In this research, a novel strategy was suggested based on re-circulation of the generated O3 in the DBD system to enhance the PNP degradation efficiency and energy yield. The potential mechanism and possible pathway of PNP degradation were studied by EPR, ESR, DFT and GS-MS analytical tests. According to the results, the PNP degradation efficiency and energy yield increased from 57.4% to 94.4% and from 0.52 to 1.18 g kW−1h−1, respectively through ozone circulation into the DBD reactor. This was due to the more release of long-lived and short-lived reactive species (ROS) in the DBD-O3 system by the O3 circulation. The variations in pH (4–10), initial concentration (50–90 mg L−1), and the presence of co-existing substances in the water matrix had minimal impact on the DBD-O3 system, in comparison to the conventional system. The biological toxicity evaluation revealed that the hybrid DBD-O3 system transform PNP to less toxic intermediates. This study proposes a promising strategy to improve the utilization of DBD for the degradation of PNP.

Degradation of 2,4-dinitrotoluene in aqueous solution by dielectric barrier discharge plasma combined with Fe–RGO–BiVO4 nanocomposite

2,4-Dinitrotoluene (2,4-DNT) as a priority and hazardous pollutant, is widely used in industrial and military activities. In this study the synergistic effect of Fe–RGO–BiVO4 nanocomposite in a non-thermal dielectric barrier discharge plasma reactor (NTP-DBD) for degrading 2,4-DNT was evaluated. Preparation of the Fe–RGO–BiVO4 nanocomposite was done by a stepwise chemical method depositing Fe and reduced graphene oxide (RGO) on BiVO4. Field emission scanning electron microscopy (FESEM), X-ray diffraction analysis (XRD), UV–vis diffuse reflectance spectra (DRS), and energy-dispersive X-ray spectroscopy mapping (EDS-mapping) validated the satisfactory synthesis of Fe–RGO–BiVO4. To find the optimal conditions and to determine the interaction of model parameters, a central composite design (RSM-CCD) had been employed. 2,4 DNT can be completely degraded at: initial 2,4-DNT concentration of 40 mg L−1, Fe–RGO–BiVO4 dosage of 0.75 g L−1, applied voltage of 21kV, reaction time of 30 min and pH equal to 7, while the single plasma process reached a degradation efficiency of 67%. The removal efficiency of chemical oxygen demand (COD) and total organic carbon (TOC) were 90.62% and 88.02% at 30 min contact time, respectively. Results also indicated that average oxidation state (AOS) and carbon oxidation state (COS) were enhanced in the catalytic NTP-DBD process, which demonstrate the effectiveness of proposed process for facilitating biodegradability of 2,4-DNT.

Non-thermal plasma promotes boar sperm quality through increasing AMPK methylation

Boar sperm quality, as an important indicator of reproductive efficiency, directly affects the efficiency of livestock production. Here, this study was conducted to improve the boar sperm quality by using a non-thermal dielectric barrier discharge (DBD) plasma. Our results showed that DBD plasma exposure at 2.1 W for 15 s could improve boar sperm quality by increasing exon methylation level of adenosine monophosphate-activated protein kinase (AMPK) and thus improving the glycolytic flux, mitochondrial function, and antioxidant capacity without damaging the integrity of sperm DNA and acrosome. In addition, DBD plasma could rescue DNA methyltransferase inhibitor decitabine-caused low sperm quality through reducing the oxidative stress and mitochondrial damage. Therefore, the application of non-thermal plasma provides a new strategy for reducing sperm oxidative damage and improving sperm quality, which shows a great potential in assisted reproduction to solve the problem of male infertility.

Effect of biomass adsorbent on non-thermal plasma activated treatment of oil-based drilling cutting: Residual toxicity assessment

The oil-based drilling cutting (OBDC), which contain petroleum hydrocarbons produced during the oil and shale gas exploration process, are considered toxic solid waste for the environment. In this study, we introduce a promising technique by coupling non-thermal dielectric barrier discharge (DBD) plasma with biomass adsorbents (wheat stalk, straw fiber, or rice husk) to remove toxic compounds from OBDC. The results show the plasma treatment can achieve up to 90.9% degradation rate of total petroleum hydrocarbons (TPH). The introduction of 3 wt% of biomass adsorbent exhibited a significant enhancement of the energy efficiency (up to 21.9% increase using rice husk). Importantly, toxicity evaluations, such as the corn seed germination test, demonstrate a substantial reduction in the toxicity of drilling cuttings after plasma treatment, with seed germination and growth rates (using straw fiber) comparable to uncontaminated soil. Adding biomass adsorbents can also enhance the hydrophilicity of treated OBDC, increasing the presence of HCOO–, CH3HCOO–, NO3- species which further contributes to the safety and fertility of treated OBDC. Coupling non-thermal DBD plasma discharge with biomass adsorbents presents an efficient and environmentally friendly choice for the environmental treatment of OBDC in deep shale gas development.

The changed multiscale structures of tight nut (Cyperus esculentus) starch decide its modified physicochemical properties: The effects of non-thermal and thermal treatments

Non-thermal dielectric barrier discharge plasma (DBDP) and four thermal treatments, including baking (BT), high pressure cooking (HPC), radio frequency (RF) and microwave (MW) were applied to modify the structural and physicochemical properties of Cyperus esculentus starch (CES). The results showed that the thermal treatments remarkably disordered the crystalline structures of CES through weakening the double-helix conformation of amylopectin, while DBDP caused much more gentle influence on the starch structures than them. Specifically, MW induced the high-frequency displacement of polar molecules and intensive collisions between starch and water molecules, causing the largest stretching and swelling extents of amylopectin, resulting in the highest pasting and rheological viscosity of CES in four thermal treatments. As DBDP did not favor the aggregation of amylopectin chains, the deaggregated starch chains promoted the hydration effects with water molecules, boosting the final pasting viscosity, apparent rheological viscosity, freeze-thaw stability and digestion velocity of CES. Besides, the gelatinization-retrogradation process in the thermal treatments regulated starch digestion velocity and produced type III resistant starch in CES. Conclusively, the modified physicochemical properties of CES resulted from the altered molecular structures of starch by the applied treatments.

Inactivation of Cercospora lactucae-sativa through Application of Non-Thermal Atmospheric Pressure Gliding Arc, Tesla Coil and Dielectric Barrier Discharge Plasmas

Cercospora leaf spot disease is a serious problem for lettuce cultivation worldwide. Cercospora lactucae-sativa, the causative agent of leaf spot disease on lettuce, was treated with non-thermal atmospheric pressure gliding arc (GA), tesla coil (TC) and dielectric barrier discharge (DBD) plasmas for the in vitro fungal inactivation of both mycelial growth and conidial germination. The fungus was exposed to the three plasmas individually for 5, 10, 15 and 20 min. The results showed that DBD plasma inactivated fungal growth during all exposure periods, and the highest inhibitory effect was caused by exposure to DBD plasma for 20 min, at 93.33% inhibition. The germination of fungal conidia was completely inactivated after exposure to all three non-thermal plasmas for 5 min, as observed 4 and 24 h after incubation. The pathogenesis of C. lactucae-sativa on lettuce after plasma treatments for 5 min was examined by spraying an inoculation of the treated conidia on lettuce. The results showed that all three plasmas reduced the disease incidence and severity compared to the non-treated control. Therefore, the non-thermal atmospheric pressure GA, TC and DBD plasmas have antifungal potential for the inactivation of C. lactucae-sativa, making them an interesting novel technology for plant disease control.

Non-thermal plasma catalytic dry reforming of methane over Ni-Co3O4 supported modified-titania catalysts: Effect of process conditions on syngas production

The dry reforming of methane has been studied over modified TiO2-supported 10%Ni-5%Co3O4 composite catalysts using a non-thermal plasma dielectric barrier discharge fixed-bed reactor. The 10%Ni-5%Co3O4/modified-TiO2 nanorods (NR) have been synthesized by hydrothermal method. Physicochemical characterizations of the composite catalysts have been conducted by X-ray diffraction (XRD), H2 temperature-programmed reduction (H2-TPR), CO2 temperature-programmed desorption (CO2-TPD), high-resolution transmission electron microscopy (HRTEM) and N2 adsorption-desorption (BET) analysis. Incorporation of cubic-structured Co3O4 into Ni/TiO2 attributes to the enhancement of basicity, reducibility and metal-support interaction. Consequently, the catalytic activity of 10%Ni-5%Co3O4/TiO2 NR increases and confer CH4 and CO2 conversions at 86.4% and 84.9%, respectively. Meanwhile, the H2 and CO selectivity are reported as 50.1% and 49.0% respectively. Higher syngas ratio (H2/CO) from 0.84 to 1.01 and 26% increment in overall energy efficiency compared to plasma DRM alone have been observed. The superior plasma DRM performance is correlated to the greater basicity properties and the synergistic effect of non-thermal plasma with the 10%Ni-5%Co3O4/modified-TiO2 catalyst composite.

Hierarchical Structures Formed in an Atmospheric Pressure Plasma Jet by Polymerization from an Aerosol of Oxalic Acid Stabilized WO3–x Nanosheet Colloids: Toward High-Performance Electrochemical Devices and Sensors

The development of microstructures which combine high total surface area and high porosity is crucial for technologies such as electrocatalysis, electrochromics, and sensors. High deposition rate, composition control of deposition, and low processing temperature to retain active compositions are also desirable. To this end, this study describes combining colloidal sol chemistry with a nonthermal atmospheric pressure dielectric barrier discharge plasma jet to print hybrid inorganic/organic tungsten trioxide/oxalic acid (WO3–x/OA) microspheres. Injection of an aerosol of oxalic acid stabilized colloidal tungstic acid into an atmospheric pressure plasma jet results in the deposition of spherical structures in which the colloid is trapped within a plasma-polymerized organic shell. Subsequent low-temperature sintering produces hierarchical spherical shell-like structures comprising tungsten oxide nanosheets. Alteration of the gas flow rate changes the composition of the deposited material. The method has promise for the general preparation from colloidal precursors of porous materials of controlled morphology and composition with hierarchical microstructures, such as are required for applications in electrochemical devices and sensors which need a high ratio of surface area to volume and connectivity throughout the structure, yet also need a microstructure which is open for rapid exchange of reactants.

Bacterial Sterilization Using Non-Thermal Plasma Method Surface Dielectric Barrier Discharge (SDBD): Effect of Treatment Duration on Colony Count, DNA, Protease Enzymes, and Cell Morphology

The ability of Escherichia coli to become increasingly resistant to sterilization has resulted in high cases of this bacterial infection. To overcome this problem, a new method is needed. The circuit design uses 2 parallel plates of copper material. The first plate is HV electrode and second plate is ground electrode which is separated by a dielectric layer. Non-thermal plasma with surface dielectric barrier discharge is generated using a 20 VDC voltage source and then transformed into a high voltage source to generate plasma. Distance between plasma source and fixed sample is 3 mm. OES is used to observe reactive species produced in plasma indicated by magnitude of intensity at certain wavelengths. SDBD non-thermal plasma could be used to inactivate bacteria depending on treatment time. The longer treatment time, greater inactivation ability. For the number of colonies after being treated for 120 s, namely 4.33×107 CFU/mL, it was much lower than control, which was 409×107 CFU/ml. For DNA after being treated for 120 s, results of genome from Escherichia coli were no longer visible or faded, marked by a DNA concentration of 8.18 ng/ul, far lower than the control DNA concentration of 124.44 ng/ul. For the activity of the protease enzyme, the time variation of 105 s had the smallest activity value of the protease enzyme, namely 35.375 U/mL compared to control, which was 52.307 U/mL whereas for cell morphology after 120 s treatment showed increasingly severe cell damage observed using SEM. Non-thermal plasma SDBD configurations can be used to inactivate or kill bacteria. Effectiveness or capability of non-thermal plasma also depends on the treatment time. SDBD nonthermal plasma ability increases with the longer treatment time. HIGHLIGHTS In this research, a non-thermal plasma method of surface dielectric barrier discharge (SDBD) for Escherichia coli sterilization was developed. The results of research on inactivation of Escherichia coli bacteria using non-thermal plasma SDBD showed that the configuration of non-thermal plasma SDBD could be used to inactivate or kill bacteria. The effectiveness or capability of non-thermal plasma also depends on the treatment time. SDBD non-thermal plasma capability increases with longer treatment time. GRAPHICAL ABSTRACT

Effect of non-thermal plasma dielectric barrier discharge reactor on the quality of biomass gasification product gas from the gasifier

The primary goal of this research is to determine the effect of key processing parameters of dielectric barrier discharge (DBD) reactor on the components concentration of the fuel gas produced during the biomass gasification. By changing key processing parameters such as plasma input power, flow rate, and temperature, the performance of the DBD reactor is assessed. When the power is increased from 5 to 40 W, the concentrations of CO2 and H2 decrease to 12.9% and 18.5%, respectively, while the concentration of CO increases to 17.2%. At 40 W and 65 ml/min, the amount of tar compound significantly drops from 33 g/Nm3 to less than 1 g/Nm3. However, as input power increases, the concentration of C1–C5 hydrocarbons also tends to rise. The highest concentration of C1–C5 was around 0.60% at 40 W. As the flow rate increases, the concentration of CO2 increases while the concentration of CO tends to decrease at all measured power levels, the maximum concentration of CO2 was at 120 ml/min, whereas the minimum concentration of CO is seen under same conditions. With an increase in flow rate, the concentration of CH4 shows a decreasing tendency. It is seen that at 40 W, the concentration of CO and H2 drops as the temperature rises up to 400 °C. In contrast, there is a rising trend in the concentration of CO2, CH4, and tar compounds while increasing temperature. Hence, the DBD reactor appears to have a profound influence on a gas component produced during biomass gasification.

Modelling of Nonthermal Dielectric Barrier Discharge Plasma at Atmospheric Pressure and Role of Produced Reactive Species in Surface Polymer Microbial Purification

A nonthermal atmospheric plasma reactor was used to sterilize polymer surfaces and satisfy safety constraints in a biological medium. A 1D fluid model was developed using COMSOL Multiphysics software® 5.4 with a helium-oxygen mixture at low temperature for the decontamination of bacteria on polymer surfaces. An analysis of the evolution of the homogeneous dielectric barrier discharge (DBD) was carried out through studying the dynamic behavior of the discharge parameters including the discharge current, the consumed power, the gas gap voltage, and transport charges. In addition, the electrical characteristics of a homogeneous DBD under different operating conditions were studied. The results shown that increasing voltage or frequency caused higher ionization levels and maximum increase of metastable species' density and expanded the sterilization area. On the other hand, it was possible to operate plasma discharges at a low voltage and a high density of plasma using higher values of the secondary emission coefficient or permittivity of the dielectric barrier materials. When the discharge gas pressure increased, the current discharges declined, which indicated a lower sterilization efficiency under high pressure. A short gap width and the admixture of oxygen were needed for sufficient bio-decontamination. Plasma-based pollutant degradation devices could therefore benefit from these results.

Non-thermal plasma dielectric barrier discharge reactor stability analysis using fiber bragg grating sensor

The main focus in this study is to determine the stability of the plasma generated by a Dielectric Barrier Discharge (DBD) reactor in the presence and without glass beads as dielectric enhancement. The stability of plasma was determined based on plasma temperature which measured within plasma stream. The DBD plasma reactor was designed, fabricated and being operated in an open air system. Fiber Bragg grating (FBG) was used to measure the plasma temperature. The applied voltage was increased up to 8 kV to determine breakdown voltage and evaluate plasma stability with and without the presence of glass beads as dielectric enhancement. Experimental results revealed that plasma started to generate at applied voltage about 3.0 kV. Plasma formation found generated with stable at applied voltage 8 kV for both with and without the presence of glass beads. With the presence of glass beads, the plasma temperature found much higher about 180 °C compare with without glass beads which is about 90 °C, and yet the plasma generation is still stable.

Potential of Nonthermal Atmospheric-Pressure Dielectric Barrier Discharge Plasma for Inhibition of Athelia rolfsii Causing Southern Blight Disease in Lettuce

Athelia rolfsii is one of the most destructive and aggressive fungal pathogens worldwide and causes southern blight disease of lettuce. A nonthermal atmospheric-pressure dielectric barrier discharge (DBD) plasma has attracted interest as an alternative control method to chemical usage because of its antimicrobial activity. Exposure of A. rolfsii to DBD plasma for 5, 10, 15, and 20 min resulted in in vitro fungal inhibition of mycelial discs and sclerotia. The results showed that DBD plasma exposure for 10 min completely inhibited fungal growth of mycelial discs, whereas exposure for over 20 min was required to inhibit the hyphal growth of sclerotia. Scanning electron microscopy (SEM) observations of mycelia and sclerotia abnormalities revealed laceration and damage of both mycelia and sclerotia. In addition, disease incidence and severity were reduced in mycelial and sclerotia inoculation following DBD plasma exposure for 15 and 20 min, respectively, compared with the positive control. In conclusion, the DBD plasma demonstrates antifungal activity against A. rolfsii via inhibition of fungal growth and reduction in disease incidence and severity. Therefore, DBD plasma has the potential to be applied in controlling southern blight disease of lettuce.

Processing laser ablated plasmonic nanoparticle aerosols with nonthermal dielectric barrier discharge jets of argon and helium and plasma induced effects

Dielectric-barrier-discharge (DBD) plasma jets provide viable state-of-the-art nonthermal processes for a wide range of nanomaterials including particle transport and deposition. We report the interaction of argon and helium plasma jets with the particle aerosol, produced by ns laser ablation of a silver target and subsequently their transport for deposition on a distant substrate. The nanofeatures and functionality of the nanoparticles, entrained and deposited with the two plasma jets were compared using high-resolution electron microscopy, helium ion microscopy, scanning electron microscopy, ultraviolet–visible spectroscopy, and in terms of the SERS effect. The plasma jet facilitates the transport of the particle aerosol under the upshot of plasma ionic wind, caused by the high electric field in the plasma. Compared to the helium plasma jet, the argon plasma jet leads to a relatively large particle deposition and promotes the formation of aggregates. The helium plasma jet enabled the deposition of spatially well dispersed particles. In both cases, the deposited particle was crystalline and plasmonic active. The plasma-driven altered morphology, expedient particle transport, and formation of agglomerates or spatially well dispersed particles are explained in plasma-induced ionic-wind, and dusty plasma framework. The findings are novel and interesting from the perspective of plasma–surface deposition, surface nanoengineering, and nanomaterial processing for applications in sensing, catalysis, surgical tools, futuristic coating technology, and heat-sensible biological activities.

Dielectric barrier discharge plasma catalysis as an alternative approach for the synthesis of ammonia: a review.

Numerous researchers have attempted to provide mild reactions and environmentally-friendly methods for NH3 synthesis. Research on non-thermal plasma-assisted ammonia synthesis, notably the atmospheric-pressure nonthermal plasma synthesis of ammonia over catalysts, has recently gained attention in the academic literature. Since non-thermal plasma technology circumvents the existing crises and harsh conditions of the Haber-Bosch process, it can be considered as a promising alternative for clean synthesis of ammonia. Non-thermal dielectric barrier discharge (DBD) plasma has been extensively employed in the synthesis of ammonia due to its particular advantages such as the simple construction of DBD reactors, atmospheric operation at ambient temperature, and low cost. The combination of this plasma and catalytic materials can remarkably affect ammonia formation, energy efficiency, and the generation of by-products. The present article reviews plasma-catalysis ammonia synthesis in a dielectric barrier discharge reactor and the parameters affecting this synthesis system. The proposed mechanisms of ammonia production by this plasma catalysis system are discussed as well.