Plasma Treatment Time Research Articles

Effects of gas type and cold plasma treatment time on Lecanicillium fungicola spores reduction and changes in qualitative, chemical, and physiological characteristics of button mushroom during postharvest storage

This study aimed to inhibit the growth of Lacanicillium fungicola and improve the quality of button mushroom during a 21-day storage time at 4°C using the treatment of surface dielectric barrier discharge plasma. Three gases of argon (Ar), surface evaporation of hydrogen peroxide (H2O2vapor) by argon and H2O2vapor by air were used as the injecting gas within processing times of 30, 60, 120, and 180 s. The results showed that 180 s treatment with H2O2vapor+Air plasma decreased L. fungicola spores about 3-log compared with untreated samples after 21 days of storage. In addition, physicochemical and physiological properties of button mushroom were investigated during the storage period. Polyphenol oxidase and peroxidase enzymes residual activity of samples treated by 180 s of H2O2vapor+Ar plasma reduced 93.95% and 94.1% immediately after treatment, respectively. Furthermore, stiffness, color, phenolic and antioxidant compounds on the 21st day of storage improved compared with untreated samples. Novelty impact statement The mixture of hydrogen peroxide vapor with air as injecting gas plasma was able to inactivate Lacanicillium fungicola spores on the surface of button mushrooms. 180 s treatment with hydrogen peroxide vapor with argon gas plasma improved the color, firmness, phenolic and antioxidant content than control. The treatment by surface dielectric barrier plasma increased the shelf life of button mushroom by reducing the activity of lipid oxidation and PPO, POD enzymes residual activity.

Influence of oxygen plasma treatment on structural and spectral changes in gold nanorods immobilized on indium tin oxide surfaces.

Oxygen plasma treatment is commonly used to sterilize gold nanoparticles by removing chemical contaminants from their surface while simultaneously inducing surface activation and functionalization of nanoparticles for biological, electrocatalytic, or electrochemical studies. In this study, we investigate the influence of oxygen plasma treatment on structural and localized surface plasmon resonance (LSPR) spectral changes of anisotropic gold nanorods (AuNRs) immobilized on an indium tin oxide (ITO) glass substrate. Unlike AuNRs deposited on a glass slide, no noticeable structural change or deformation of AuNRs on ITO was observed while increasing the oxygen plasma treatment time. This result indicates that ITO provides structural stability to AuNRs immobilized on its surface. Additionally, single-particle scattering spectra of AuNRs showed the broadening of LSPR linewidth within 60s of oxygen plasma treatment as a result of the plasmon energy loss contributed from plasmon damping to ITO due to the removal of capping material from the AuNR surface. Nevertheless, an increase in the surface charge on the AuNR surface was observed by narrowing the LSPR linewidth after 180s of plasma treatment. The electrochemical study of AuNRs immobilized on ITO electrodes revealed the surface activation and functionalization of AuNRs by increasing plasma treatment. Hence, in this study, a significant understanding of oxygen plasma treatment on AuNRs immobilized on ITO surfaces is provided.

Effect of high-power electromagnetic pulses and dielectric barrier discharges on physicochemical and flotation properties of perovskite

The methods of FTIR, SEM–EDX, microhardness test, electrokinetic potential and contact angle measurements, as well as the sorption and flotation experiments are used to study the influence of high-power electromagnetic pulses (HPEMP) and dielectric barrier discharge (DBD) on the structural, physicochemical and flotation properties of perovskite (Afrikanda deposit). The analysis of FTIR data shows that short treatment times (t treat = 10 t 0÷30 s) lead to opposite changes in the surface condition of perovskite: oxidation (hydration) of the surface in case of HPEMP and deoxidizing (dehydration) under DBD. According to SEM results, the surface of perovskite undergoes destruction as a result of HPEMP and DBD treatment. The surface of some areas of the samples is modified with the formation and opening of deep parallel cracks, most likely due to the polysynthetic twinning typical of perovskite crystals; the subparallel pyramidal protrusions are also observed in some surface areas. The determined morphological changes cause softening and a monotonic decrease in the microhardness of the mineral surface with an increase of the HPEMP and DBD (plasma) treatment times (ttreat = 0 t 0÷150 s) by ΔHVmax V = 27 x 7÷33%. The effect of HPEMP and DBD on the physicochemical properties of the mineral surface represents a shift in the electrokinetic potential towards positive values, an increase in the contact angle (t treat = 10 t 0÷30 s), as well as the improved adsorption of the collector and the higher flotation activity of perovskite by ~ 10–15%. The authors express their gratitude to Candidate of Geological and Mineralogical Sciences E.V. Koporulina and to Candidate of Engineering Sciences N.E. Anashkina for their help in the experimentation.The study was supported by the Ministry of Science and Higher Education of the Russian Federation, Project No. 13.1902.21.0018, Agreement No. 075-15-2020-802.

A simple derivative spectrophotometric method for simultaneously detecting nitrate and nitrite in plasma treated water

A spectrophotometric technique is developed to simultaneously quantify nitrate and nitrite in plasma treated water. The measurement is based on examining the inflection points (wavelengths) in the derivative absorbance of the nitrate or nitrite solution. At the inflection points of the pure nitrate solution, the derivative absorbance is zero and independent of the nitrate’s concentration, and thus the nitrite’s concentration in a mixed nitrate and nitrite solution can be obtained by using the Beer’s law at these points. The nitrate’s concentration can also be achieved from the inflection points of nitrite in the same manner. The relation between the tested substance’s (nitrate or nitrite) concentration and the second- or the third-order absorbances is obtained at these inflection points. Test measurements for mixed aqueous solutions of nitrate and nitrite with or without hydrogen peroxide confirm the reliability of this technique. We applied this technique to quantify the nitrate and nitrite generated in air plasma treated aqueous solutions. The results indicate that both nitrate and nitrite concentrations increase with the plasma treatment time, and the nitrite species is found to be generated prior to the nitrate species in the air plasma treated aqueous solution. Moreover, the production rate of total nitrogen species is independent of the solutions’ pH value. These results are relevant to diverse applications of plasma activated solutions in materials processing, biotechnology, medicine and other fields.

Effect of cold atmospheric plasma torch distance on the microbial inactivation and sensorial properties of ready-to-eat olivier salad.

This study aimed to investigate the effect of the cold atmospheric plasma torch (CAPT) nozzle distance from the surface of Olivier salad and the treatment time in the reduction of microbial load and sensory properties of the product simultaneously. In this study, the CAPT nozzle was placed at 3, 5, and 7 cm distances from the surface of the Olivier salad, and its efficiency in inactivating the microbial population, decimal reduction time (D-value), and sensory evaluation of the product were evaluated. The results showed that reducing the distance and increasing the plasma treatment time (30, 60, 90, and 120 s) both reduced the microbial load of the product. The maximum inactivation and the minimum D-value are related to the 3 cm distance for 120 s, which has been 3.77, 2.91, and 1.52 log CFU/g for Coliform, Total viable count (TVC), mold and yeast, respectively. The lowest D-value was related to Coliform (4.41 s). CAPT treatment had no significant sensible effect on the product's sensory characteristics compared to the control sample. The treated sample at a 3 cm distance for 90 s and the microbial reduction to an acceptable amount and high acceptancy from sensory evaluators were selected as the superior treatment in this study. Also, the results showed that CAPT could be used successfully in ready-to-eat (RTE) products.

Study of oxygen plasma treatment on solution-processed SnO x thin-film transistors

In this study, the effect of oxygen plasma treatment (OPT) on the electrical performance of the SnO x thin film transistors (TFTs) were investigated. The SnO x thin films were fabricated by solution process and integrated into the TFTs as channels. According to the x-ray photoelectric spectroscopy analysis, the oxygen vacancies in the SnO x thin films are significantly reduced after OPT. The electrical performances of the SnO x TFTs treated with various plasma power and treatment time were systematically studied. Compared with untreated SnO x TFT, the one with OPT of 40 W for 90 s exhibits optimum electrical performance, including the variation of the current on/off ratio (I on/I off) from ∼103 to 107 and threshold voltage (V TH) from −10.78 to 3.97 V. Meanwhile, the operation mode of the SnO x TFTs is changed from depletion mode to enhancement mode. When the SnO x TFT is integrated with high-k Al2O3 dielectric, the TFT exhibits better electrical performance, including the V TH of 0.14 V, an I on/I off of 107, a field-effect mobility (µ FE) of 5.57 cm2 V−1 s−1, and a subthreshold swing of 570 mV dec−1. These results prove that the OPT process for SnO x TFTs is a facile and efficient method in the flat panel display industries.

Work function of the oxygen functionalized graphenic surfaces – Integral experimental and theoretical approach

The effect of oxygen plasma functionalization of graphenic surface was thoroughly investigated experimentally (SEM, XPS, Raman spectroscopy, work function measurements, TG) and corroborated by DFT molecular modeling using periodic slabs (work function, surface dipoles, EF/DOS). It was found that the introduction of oxygen substantially modified the electrodonor properties of the graphenic surface and the work function changed in a non-monotonous way upon the plasma treatment time. At the short contact time (5–30 s) the work function significantly increased from 4.2 eV (parent graphenic surface) to 5.6 eV and after passing the maximum value it reached plateau at the level of 5.2 eV after 100–150 s. The XPS revealed that the plasma treatment leads to an increase in the oxygen surface concentration (up to ∼10 at.%). A comparison of SEM images and Raman spectra of unmodified and plasma-modified graphenic surfaces indicated that the induced changes are limited to the outermost surface. Indeed, the TGA stability profiles did not indicate any bulk structural changes. Based on the experimental and DFT results, the molecular models of the surface modification process was proposed taking into account the various location of surface oxygen functionalities. At the early stage of the plasma treatment, a generation of strongly polar surface functional groups (surf-OH with the local dipole moment of2.7 D) leads to the formation of an electrostatic potential barrier for electron transfer from the surface (observed increase in work function). Prolonging modification results in the insertion of oxygen heteroatoms into the carbon surface, more uniform electron density distribution, and hence work function decrease. Since the electronic properties of graphenic materials play a key role in their various applications, the obtained results provide rational guidelines for their design and optimization.

Inactivation of E. coli, S. aureus, and Bacteriophages in Biofilms by Humidified Air Plasma.

In this study, humidified air dielectric barrier discharge (DBD) plasma was used to inactivate Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and bacteriophages in biofilms containing DNA, NaCl, carbohydrates, and proteins. The humidified DBD plasma was very effective in the inactivation of microbes in the (≤1.0 μm) biofilms. The number of surviving E. coli, S. aureus, and bacteriophages in the biofilms was strongly dependent on the constituent and thickness of the biofilms and was greatly reduced when the plasma treatment time increased from 5 s to 150 s. Our analysis shows that the UV irradiation was not responsible for the inactivation of microbes in biofilms. The short-lived RONS generated in the humidified air DBD plasma were not directly involved in the inactivation process; however, they recombined or reacted with other species to generate the long-lived RONS. Long-lived RONS diffused into the biofilms to generate very active species, such as ONOOH and OH. This study indicates that the geminated NO2 and OH pair formed due to the homolysis of ONOOH can cause the synergistic oxidation of various organic molecules in the aqueous solution. Proteins in the biofilm were highly resistant to the inactivation of microbes in biofilms, which is presumably due to the existence of the unstable functional groups in the proteins. The unsaturated fatty acids, cysteine-rich proteins, and sulfur–methyl thioether groups in the proteins were easily oxidized by the geminated NO2 and OH pair.

Effect of atmospheric nonthermal plasma on physicochemical, morphology and functional properties of sunn pest (Eurygaster integriceps)-damaged wheat flour.

To improve the quality of sunn pests (Eurygaster integriceps)‐damaged wheat flour, the effects of nonthermal plasma on physicochemical, rheological, functional, and microstructural properties were investigated. Gas type (air and oxygen), voltage (22 and 25 volts), and time (0, 2, 4, 6, 8, and 10 min) were the variables of the experiments conducted using a completely randomized design with three replications. The results show that with increasing voltage and time of plasma treatment, the pH decreased significantly (p ≥ .05), and brightness parameter, yellow–blue parameter, water‐solubility, water absorption, oil absorption, and swelling power increased significantly (p ≥ .05). The duration of plasma treatment, voltage, and change in input gas from air to oxygen did not significantly change the gluten index, particle size, and negative electric charge of flour particles, and the amount of zeta potential of samples. Differential calorimetric analysis showed the first and second peaks of the thermogram in the range 55–99°C and also 114–99°C. Infrared spectroscopy (FT‐IR) showed hydroxyl group, CH bonds, C=O bonds, as well as the presence of types I and II amide bonds in the structure. Microstructural results indicated that plasma treatment reduced the particle size and increased particle sorting. By Increasing voltage and the duration of plasma treatment, peak viscosity, final viscosity, breakdown viscosity, pasting time and temperature significantly increased and setback viscosity decreased (p ≥ .05), which reduced retrogradation which improved the dough stability during the cooling process.

Nanosecond-pulsed DBD plasma treatment on human leukaemia Jurkat cells and monoblastic U937 cells in vitro

Plasma therapy offers an exciting and novel way of cancer treatment. Specifically, it is shown that Jurkat death rates are closely governed by the plasma treatment time. However, apart from time, alterations to different parameters of treatment process may yield better results. Here, Dielectric barrier discharge (DBD) reactors excited by a nanosecond-pulse energy source are used to investigate cell viability for longer exposure times as well as the effects of polarity of reactor on treatment. Plasma discharge regimes are discussed and assessed using imaging and thermal imaging methods. We found that by changing the polarity of reactor i.e. changing the direction of plasma discharge, the plasma discharge regime changes influencing directly the effectiveness of treatment. Our results showed that ns-DBD− reactor could induce both apoptosis and necrosis of human Jurkat and U937 cells, and this cytotoxic effect of plasma was not completely antagonized by N-acetyl cysteine. It indicates that plasma could induce ROS-independent cell death. Gene expression analyses revealed that p53, BAD, BID and caspase 9 may play vital roles in plasma caused cell death. In addition, our findings demonstrate how different parameters can influence the effectiveness of our reactors. Our assay reveals the custom ability nature of plasma reactors for hematologic cancer therapy and our findings can be used for further development of such reactors using multi-objective optimisation techniques.

P-Nitrophenol contaminated soil remediation in a spray-type coaxial cylindrical dielectric barrier discharge plasma system.

In the present work, plasma remediation of p-nitrophenol (PNP) contaminated soil was performed in a novel spray-type coaxial cylindrical dielectric barrier discharge (DBD) system at ambient temperature. This system is capable of generating large-size nonthermal plasma (NTP) and improving the diffusion and transfer of chemical active species around the dispersed soil particles. Several key parameters including plasma treatment time, discharge voltage, soil granular size, the entry speed of soil, PNP initial concentration, gas variety, and gas flow rate were investigated in terms of PNP degradation and energy efficiencies. Under the optimized experimental conditions, 54.2% of PNP was degraded after only 50 s discharge treatment, indicating that the spray-type coaxial cylindrical DBD system can degrade organic pollutants in soil more quickly compared to other plasma systems due to its efficient transfer of reactive oxygen and nitrogen species (RONS) into the contaminated soil. The possible PNP degradation pathways were proposed based on intermediates identification results and the role of reactive species analysis. The toxicological assessment of the PNP decomposition products was conducted by quantitative structure-activity relationship (QASR) analysis. This work is expected to provide a potential plasma technology for rapid and efficient processing of industrial organic pollutants contamination soil.

1D fluid model of the interaction between helium APPJ and deionized water

Atmospheric pressure plasma jets (APPJs) are widely used for the treatment of water-containing substances such as human tissue, leading to a necessity of understanding the interaction between APPJs and water solutions for the development of plasma biomedicine. The reported two- or three-dimensional fluid models are shown to be an effective method for this study. However, owing to the complex chemistry in APPJ-water interaction, little of them could provide a quantitative estimation of reactive species, which are difficult to be measured but of much interest in the applications. In this paper, a one-dimensional fluid model is developed to simulate the interaction between a helium APPJ and deionized water, which incorporates a relatively comprehensive chemistry both in gas and liquid phases but with a moderate computational load. The composition and distribution of reactive species are quantified during a plasma treatment time of 6 min, which is typical in practice. By considering the sidewise loss inside the quartz tube, the air mixing outside the quartz tube, the conductivity of deionized water, and the chlorine evolution reaction, the simulation results agree well with the experiments. It is found that the plasma could be divided into three regions with much different physicochemical properties, mainly due to the sidewise loss, the air mixing and the water evaporation. In plasma-activated water, H2O2aq and HNO2aq/NO2aq − are the dominant reactive species, and OHaq is the key intermediate species for the transformation among other reactive species. Finally, the chemical pathways for the production of aqueous reactive species are elucidated.

Rapid and Continuous Atmospheric Plasma Surface Modification of PAN-Based Carbon Fibers.

In this work, a continuous and rapid atmospheric plasma setup was developed for rapidly modifying the surface of PAN-based carbon fibers (CFs). The interlaminar shear strength (ILSS) of CFs increased from 64.9 to 80.0 MPa with 60 s plasma treatment. Further mechanical and surface structural characterizations revealed that the effect of plasma was different, depending on the treatment time. When the treatment time was lower than 15 s, the effect of plasma was mainly on physically etching the surface of CFs, and the ILSS of CFs increased rapidly. Further extending the plasma treatment time did not increase surface roughness but promoted the addition of oxygen-containing functional groups on the surface of CFs, corresponding to a slower growth rate of ILSS. The atmospheric plasma was generated via a dielectric barrier discharge (DBD) method, and its energy intensity was significantly lower than that of plasma generated under low pressure. Accordingly, a mechanism was proposed for the plasma treatment of CFs: atmospheric plasma was not strong enough to simultaneously etch all the carbon atoms on the surface of CFs; therefore, carbon atoms on the graphitic plane were selectively etched, followed by the attaching of oxygen-containing functional groups on the exposed carbon sites caused by etching.

Tuning the structure, optical, and magnetic properties of nanostructured NiMoO4 by nitrogen plasma treatment

Herein, the nitrogen plasma treatment with different time irradiation (0, 90, 120, and 150 min) is used to tune the structure, optical, and magnetic properties of nanostructured NiMoO4 NMO NPs. The XRD patterns revealed that the crystallinity of NMO samples increases with an increase in the N2 plasma exposure time. The notable reduce in this peak’ intensity for the sample at dose of 120 min may be attributed to the energy dissipated in the defect generation. Also, the crystallite size for NMO samples was found in the range (23.9–26.7) nm. Further, EPR is used to evaluate the impact of the treatment duration on the oxygen vacancy density. The total number of spins rises as plasma irradiation duration increases, revealing that the NMO NPs can be used as a dosimeter for plasma irradiation. The optical bandgap ranged from 2.92 eV to 3.24 eV as the N2 plasma treatment duration changed. The saturation magnetization was enhanced with the rise of plasma treatment time. Furthermore, the Hc increases from 16.67 G for untreated NMO NPs to 128.41 G for N2 plasma-treated NMO NPs for 150 min. The resulted optical and magnetic properties of N2 plasma-treated NMO NPs make it candidate material for photocatalysis applications.

RNA Sequencing of Arabidopsis thaliana Seedlings after Non-Thermal Plasma-Seed Treatment Reveals Upregulation in Plant Stress and Defense Pathways

Not all agricultural practices are sustainable; however, non-thermal plasma treatment of seeds may be an eco-friendly alternative to improve macroscopic plant growth parameters. Despite the numerous successful results of plasma-seed treatments reported in the literature, there is a large gap in our understanding of how non-thermal plasma treatments affect seeds, especially due to the plethora of physical, chemical, and biological variables. This study uses RNA sequencing to characterize the changes in gene transcription in Arabidopsis thaliana (L.) Heynh. seeds 6 days after exposure to surface dielectric barrier discharge plasma treatment. Here, we provide an overview of all pathways that are differentially expressed where few genes are upregulated and many genes are downregulated. Our results reveal that plasma treatment time is a parameter that can activate different pathways in plant defense. An 80 s treatment upregulates the glucosinolate pathway, a defense response to insects and herbivores to deter feeding, whereas a shorter treatment of 60 s upregulates the phenylpropanoid pathway, which reinforces the cell wall with lignin and produces antimicrobial compounds, a defense response to bacterial or fungal plant pathogens. It seems that plasma elicits a wounding response from the seed in addition to redox changes. This suggests that plasma treatment can be potentially applied in agriculture to protect plants against abiotic and biotic stresses without discharging residues into the environment.

Irrigation of peritoneal cavity with cold atmospheric plasma treated solution effectively reduces microbial load in rat acute peritonitis model

Accurate and timely diagnosis of appendicitis in children can be challenging, which leads to delayed admittance or misdiagnosis that may cause perforation. Surgical management involves the elimination of the focus (appendectomy) and the reduction of the contamination with peritoneal irrigation to prevent sepsis. However, the validity of conventional irrigation methods is being debated, and novel methods are needed. In the present study, the use of cold plasma treated saline solution as an intraperitoneal irrigation solution for the management of acute peritonitis was investigated. Chemical and in vitro microbiological assessments of the plasma-treated solution were performed to determine the appropriate plasma treatment time to be used in in-vivo experiments. To induce acute peritonitis in rats, the cecal ligation and perforation (CLP) model was used. Sixty rats were divided into six groups, namely, sham operation, plasma irrigation, CLP, dry cleaning after CLP, saline irrigation after CLP, and plasma-treated saline irrigation after CLP group. The total antioxidant and oxidant status, oxidative stress index, microbiological, and pathological evaluations were performed. Findings indicated that plasma-treated saline contains reactive species, and irrigation with plasma-treated saline can effectively inactivate intraperitoneal contamination and prevent sepsis with no short-term local and/or systemic toxicity.

Influence of Plasma Surface Treatment of Polyimide on the Microstructure of Aluminum Thin Films

The effects of plasma treatment of polyimide substrates on the texture and grain size distribution of aluminum thin films were studied. Oxygen-argon plasma treatment increased the average grain size and enhanced the (111) film texture. For short oxygen-argon plasma treatment times, the deposited Al films showed a (111) texture with a bimodal grain structure and even a {111}<112¯> type in-plane texture. The preferential nucleation and grain growth of (111) grains are discussed in terms of the interface energy anisotropy.

Improved performance of flexible citrus resistive memory device through air plasma

Flexible natural material-based electronics have attracted considerable attention because it can be applied in wearable applications and bio smart electronics. Natural material citrus is used as the dielectric layer in this work to develop flexible resistive switching memory devices, with plasma ITO surface as the bottom electrode (BE) to investigate the effects of air plasma on device performances. The work function difference between the top electrodes (TE) and BE can be increased with plasma treatment. After optimization, the flexible citrus resistive memory device with a large work function difference between the TE and BE exhibits a good ON/OFF ratio of larger than 103, a low set voltage of around 0.76 V, uniform distribution of set voltages, small coefficients of variation of high resistance state, and low resistance state currents, and a long retention time of more than 104 s. The air plasma can also modify the ITO surface to make the surface more hydrophilic. Thus, the citrus film is easier to attach to ITO, which improves the bending performance of the device. The device under a bending radius of 4.9 mm showed no significant ON/OFF ratio changes when compared with that of the flat state. This information on the correlation between the plasma treatment time and the work function of the ITO electrode would be very useful in obtaining stable and uniform resistive switching properties in the flexible natural material-based resistive memory.

Degradation of persistent organic pollutants in soil by parallel tubes-array dielectric barrier discharge plasma cooperating with catalyst

Persistent organic pollutants are harmful to the human health and environment due to their toxicity, chemical stability, degradation resistance and high bioaccumulation. In this paper, a parallel tubes-array dielectric barrier discharge reactor is developed to generate homogeneous discharge plasma and degrade the persistent organic pollutants in soil. The effects of applied voltage, initial concentration of pyrene and catalysts on the pyrene degradation efficiency in soil are studied. The results show that the degradation effect can be greatly improved by tuning these influencing parameters. The degradation efficiency of pyrene is significantly enhanced as the applied voltage increases. It reaches 96.23% at 28 kV in simulated soil and 98.26% at 26 kV in actual soil with 100 mg/kg initial concentration, and 10 min plasma treatment time. A significant promotion effect on the degradation efficiency can be obtained with the decrease of the initial pyrene concentration. Likewise, the addition of the catalysts CeO2 and TiO2 significantly improves the pyrene degradation efficiency and presents obvious synergistic effect with plasma. The discharge characteristics are discussed in combination with discharge images, waveforms of current and voltage. And the degradation mechanism of pyrene is analyzed combine with the optical emission spectra.

Effect of MoS2 on phenol decomposition in water after high-voltage pulse discharge treatment

Molybdenum disulfide (MoS2) was added to the system after being treated with high-voltage pulse discharge plasma to improve the degradation efficiency of pollutants and reduce energy consumption. The discharge plasma-treated solution contains hydrogen peroxide and metal iron ions, and MoS2 addition can cause co-catalytic Fenton reaction. The effects of discharge time, initial pH, phenol concentration, MoS2 dosage, discharge voltage, and gas type on phenol removal and aqueous H2O2 concentration were mainly investigated. Results showed that the addition of MoS2 after plasma treatment can reduce the plasma treatment time by 70% and maintain or even increase the degradation efficiency of phenol from 40% (after 20 min of discharge plasma) to 92% (after turning off the discharge and dosing with MoS2 for 30 min). Acidic conditions (pH = 3–4) and oxygen were beneficial to phenol removal. MoS2 addition greatly improved the catalytic oxidation of discharge plasma. This study provides a promising direction for water treatment based on plasma technology.