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[Display omitted] • Contact angles of anode and cathode materials are modified using plasma modification. • Interactions between plasma parameters are evaluated by Box-Behnken design. • Plasma treatment enhances flotation separation selectivity of electrode materials. • Flotation of anode and cathode materials obeys to the first order-kinetic model. • The contact angle increase of anode materials plays a major role in plasma treatment. The recycling of spent lithium-ion batteries (LIBs) can not only reduce the potential harm caused by solid waste piles to the local environment but also provide raw materials for manufacturing new batteries. Flotation is an alternative approach to achieve the selective separation of cathode and anode active materials from spent LIBs. However, the presence of organic binder on the surface of hydrophilic lithium transition-metal oxides results in losses of cathode materials in the froth phase. In this study, plasma treatment was utilized to remove organic layers from cathode and anode active materials. Firstly, the correlations between plasma treatment parameters (e.g., input power, air flowrate, and treatment time) were explored and the contact angles of cathode and anode active materials were investigated by the response surface methodology. Secondly, differences in the flotation recoveries of cathode and anode active materials were enhanced with plasma modification prior to flotation, which is consistent with the contact angle measurement. Finally, the plasma-modification mechanisms of hydrophobicity of cathode and anode active materials were discussed according to Fourier Transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analyses. The proposed method could be a promising tool to enhance the flotation separation efficiency of cathode and anode active materials for the recycling of spent LIBs. [ABSTRACT FROM AUTHOR]

The paper deals with a novel method for the edge preparation of cutting tools using an advanced approach. Cemented carbide cutting inserts were used as a sample in the experiment, and were prepared using plasma discharges in electrolyte. This technique is an environmentally-friendlier method in contrast to electropolishing treatment. The experiment aimed to determine the influence of process parameters of plasma treatment on the material removal rate and cutting edge radius size. In the experiment, concentration of electrolyte, voltage between electrodes, temperature of electrolyte, and operating time were varied. The material removal rate and cutting edge radius size increased faster with the decreasing concentration of electrolyte, decreasing voltage, and decreasing temperature of electrolyte. The material removal percentage increase was 155 percent, and 57 percent for cutting edge radius size during the 10 seconds of operation time in the specified range of process parameters. This change can be achieved by setting various process parameters. The results of the experiment proved that plasma treatment can control the forming of cutting edge radii. Cutting edge preparation using plasma discharges in electrolyte takes only a few seconds, depending on the cutting edge radius sizes. [ABSTRACT FROM AUTHOR]

In this study, we investigated the effects of helium (He) plasma irradiation and thermal treatment on the morphology, the surface characteristics, and the photoelectrochemical performance of bulk iron (Fe) sheets. After processing, all samples consisted mainly of an α -Fe 2 O 3 surface. Helium plasma irradiation resulted in a cathodic shift in the onset potential of the photocurrent from 1.16 V RHE (no pretreatment) to 0.57 V RHE (plasma exposure at 660 ° C), where V RHE represents the potential versus reversible hydrogen electrode (RHE). An increase in the surface roughness and a smaller amount of hydroxyl or oxygen vacancies at the surface after photoelectrochemical measurement are related to the decrease of the onset potential. The results show that He plasma irradiation does not only modify the surface morphology, but also affects the functional properties of the materials. • The photoelectrochemical performance of α -Fe 2 O 3 is investigated. • Helium plasma irradiation resulted in a cathodic shift in the onset potential. • The onset potential shifted from 1.16 to 0.57 V RHE. • A small amount of hydroxyl or oxygen vacancies are likely to be the most influential. [ABSTRACT FROM AUTHOR]

[Display omitted] • p-PCL demonstrated improved hydrophilicity and protein adsorption. • p-PCL altered membrane surfaces while maintaining its mechanical integrity. • p-PCL intensified the behavior of mesenchymal stem cells and osteoblast cells. • Cell behavior was regulated by cellular interaction with the p-PCL membrane. • p-PCL demonstrated enhanced bone regeneration capacity in a bone defect model. Bone defects present significant clinical challenges in orthopedics, orthodontics, and maxillofacial surgeries. Accelerated bone regeneration can be facilitated by incorporating mesenchymal stem cells, but limitations in cell survival and growth remain concerns for complete bone repair. Biomaterial-based membranes have been developed to form biocompatible, degradable, and mechanically stable barriers in guided bone regeneration processes. Polycaprolactone (PCL) is a biodegradable polymer widely used as a bone regenerative material because of its favorable mechanical properties. However, its inherent hydrophobicity limits cell adhesion and proliferation, which are necessary for effective bone regeneration. To address this, we fabricated cell-regulatory PCL nanofiber membranes using plasma treatment to enhance induced pluripotent stem cell-derived mesenchymal stem cells and osteoblast growth. The plasma treatment parameters (gas type, flow rate, power, and exposure time) were optimized to enhance PCL's surface hydrophilicity and protein adsorption properties while maintaining its mechanical integrity. The optimized oxygen plasma-modified PCL membrane demonstrated notable improvements in cell viability, adhesion, and proliferation. In addition, there was improved migration, regulated by cell surface markers and signaling proteins, of the induced pluripotent stem cell-derived mesenchymal stem cells and osteoblasts. In vivo studies in a rat calvarial defect model showed that the plasma-modified PCL membrane dramatically improved new bone formation, facilitating bone regeneration. These findings highlight the potential of plasma treatment of PCL nanofibers to produce effective cell-regulatory membranes for bone defect reconstruction. [ABSTRACT FROM AUTHOR]

The textile industry produces dye pollutants that are both harmful and difficult to degrade. This study explores the enhanced adsorption of Malachite Green (MG) dye using coconut carbon shells treated with RF glow oxygen plasma discharge. Plasma treatment improved the surface properties of the adsorbent by introducing oxygen-containing functional groups and increasing surface polarity, which boosted dye adsorption through hydrogen bonding, electrostatic interactions, and π-π stacking. Experimental results revealed that a 10-minute plasma treatment optimally enhanced adsorption capacity by 39 % compared to untreated samples. The Langmuir isotherm model demonstrated a maximum adsorption capacity (q m) of 161 mg/g, surpassing the Freundlich model. At pH 8, using 0.2 g of adsorbent in 50 mL solutions with initial dye concentrations of 25 mg/L and 100 mg/L, the 10-minute plasma-treated samples achieved adsorption capacities of 6.01 mg/g and 23.95 mg/g, respectively, compared to 4.72 mg/g and 17.2 mg/g for the untreated samples. This corresponded to removal efficiencies of 96.12 % and 95.8 % for the treated samples, and 75.6 % and 68.8 % for the untreated samples, after 80 min of contact at 200 rpm. UV–vis spectrophotometry confirmed the reduction in dye concentration after adsorption. FE-SEM analysis revealed that plasma treatment created micro-pores on the coconut carbon shell, enhancing adsorption capacity, while SEM-EDX analysis showed increased oxygen content after 10 min of treatment. FTIR analysis identified additional carbonyl (-C=O) and hydroxyl (-OH) groups, indicating the incorporation of oxygen-containing functional groups due to plasma treatment. Confocal Raman microscopy was also used to analyze the microstructural changes in the samples. [Display omitted] • RF oxygen plasma enhanced coconut carbon shell for MG dye adsorption by 39 %. • A 10-minute plasma treatment showed optimal maximum adsorption of 161 mg/g. • Structural analysis reveals microstructure and pores after plasma treatment. • Analysis shows higher O (8 % to 21.75 %) and functional groups post-plasma. • The Langmuir isotherm confirms favorable adsorption behavior. [ABSTRACT FROM AUTHOR]

In recent years, there has been a surge in interest surrounding the fabrication and utilization of superhydrophobic and superhydrophilic surfaces, driven by their exceptional functionalities and properties. Graphene Oxide (GO) has inherent hydrophilicity and underwater superoleophobicity, which has made this material a particularly capable candidate for oil-water separation. Addressing the persistent challenge of efficient oil-water separation in industrial contexts, this study presents the fabrication of a GO-coated stainless steel mesh via a facile dip coating method augmented by an intermediate two-step O 2 plasma treatment. The coated meshes were tested with various oil and water mixtures, including neutral, acidic, saline, and hot water, to find separation efficiency and recyclability. Notably, the meshes can achieve excellent separation efficiency of approximately 98.9 % and a superior flux of 11,464 L m−2 h−1 driven by gravity. This is a significant improvement over GO-coated meshes without O 2 plasma treatment. Moreover, the plasma-treated meshes exhibit robust long-term durability and chemical stability, maintaining high underwater oil contact angles ≥119° even after extended immersion in diverse pH mediums and salt solutions for 150 days. This work showcases the practical viability of plasma-treated GO-coated meshes for oil-water separation applications and establishes a framework for systematically evaluating their long-term performance in harsh immersion conditions. [Display omitted] • A superhydrophilic-underwater superoleophobic GO-coated mesh made using dip-coating. • A novel two-step O 2 -plasma treatment was introduced to improve coating durability. • Long-term continuous immersion durability studied for 150 days in various mediums. • The meshes demonstrate improved efficiency, high flux and oil-intrusion pressure. [ABSTRACT FROM AUTHOR]

[Display omitted] • The OVs concentration in N-TiO 2-x is enhanced via photoinduced strategy. • Plasma pre-treatment enhances oxygen vacancy formation on TiO 2 surfaces. • Highly efficient photocatalytic trace CH 4 conversion is achieved by N-TiO 2-x. • The synergistic mechanism of N and OVs doping is revealed. Photocatalysis employing cost-effective commercial titanium dioxide offers an ideal solution for eliminating trace methane emissions from livestock and poultry farming. However, significant challenges such as the rapid recombination of photogenerated carriers, a limited light absorption spectrum, and weak adsorption capabilities considerably hinder the effectiveness of titanium dioxide in the photocatalytic treatment of trace methane. This study proposes a novel approach to activate plasma pre-treated N-doped commercial anatase TiO 2 into dual-defect TiO 2 (N-doped TiO 2-x) featuring stable and controllable oxygen vacancies (OV) through photoinduced defect engineering. Characterizations of the photocatalyst confirm the successful creation of surface defects, further evaluated through solar-light-driven CH 4 (ppm level) removal investigations. The yield of this N-doped TiO 2-x in converting CH 4 is 4.84 μmol h−1, 44 times greater than that of unmodified TiO 2 , significantly outperforming previous studies. UV–Vis diffuse reflection spectra, and photoluminescence indicate that the modified commercial anatase TiO 2 possesses a narrower band gap, efficient photogenerated carrier separation, and enhanced charge transfer. Furthermore, density functional theory (DFT) calculations demonstrate that the synergistic effects of oxygen vacancies and N doping enhance the adsorption and activation of both O 2 and CH 4 in the rate-determining step of the reaction. This innovative strategy holds considerable promise for modifying various materials for more efficient photocatalytic applications. [ABSTRACT FROM AUTHOR]

Jute fibers are characterized by a heterogeneous chemical composition (cellulose and non-cellulosic components) and a complex layered structure with a hydrophobic surface outer layer responsible for their low wettability. In this work, after the removal of water-soluble components, raw jute fibers were subjected to atmospheric pressure dielectric barrier discharge (DBD) under different conditions (at 150 or 300 Hz) to tailor jute fiber surface structure and wettability. The research was focused on the aging effect during natural aging in a standard atmosphere investigated up to three weeks after DBD treatment. Alterations in the surface morphology of DBD-treated jute fibers were investigated by FE-SEM and AFM, while ATR-FTIR, XPS, and electrokinetic measurements were used to assess the changes in the jute fiber surface chemistry. Sorption properties were monitored through wetting time and capillary rise measurements. The sorption properties of DBD-treated jute fibers were improved (about 100 times lower wetting time and 15 % higher capillary rise height in comparison to untreated) due to the changes in surface chemistry (decreased lignin and hemicellulose content in parallel with cellulose oxidation) and morphology (about 4.6 times higher average roughness). The electrokinetic and sorption properties measurement confirmed the significance of aging effects in lignocellulosic fibers' functionalization using plasma. [Display omitted] [ABSTRACT FROM AUTHOR]

Plasma treatment is an eco-friendly and effective way to improve the chemical reactivity of wood surface. This study explores the improvemnet of bonding properties of heat-treated wood for outdoor construction applications through plasma treatment. In this work, the low temperature atmospheric barrier discharge (DBD) plasma was used to modify the surface of heat-treated wood, and then phenol-formaldehyde (PF) resin adhesive and modified wood were applied to prepare bonded wood. The in-situ chemical structure and mechanical properties of the bonding interphase were characterized by Raman spectrum, nanoindentation and digital image correlation technology (DIC) to indicate the effect of DBD modification on the bonding properties of heat-treated wood. Results showed that after plasma treatment, the hydrophilic functional groups in the cell wall were increased and the PF adhesive molecules had chemical interaction with the cell wall. The elastic modulus (E r) and hardness (H) of wood cell wall gradually decreased along the bonding interphase towards wood with the decrease of PF penetration depth, which resulted in the reduction of the mechanical properties difference between the cell wall and PF adhesive at the bonding interphase. As a result, the shear strain was distributed homogeneously due to the effective stress transmission more at the bonding interphase. The shear strength of the control bonded wood decreased by about 35 % after heat treatment at 215 °C for 2 h, while the shear strength of heat-treated wood was increased by up to 34 % after plasma treatment. • Mechanics of wood cell wall were enhenced by the infiltration of phenolic resin. • Mechanics of wood cell wall decreased as the distance from the bonding interphase increased. • The shear strength of wood decreased after heat treatment due to the low chemical reactivity of wood surface. • The shear strength of heat-treated wood increased after plasma treament. • The fracture location of bonded heat-treated wood is not concentrated upon the bonding interphase after plasma treatment. [ABSTRACT FROM AUTHOR]

Defective engineering and the addition of noble metal are effective strategies to realize the high photocatalytic performance of SrTiO 3 perovskite. Here, the Pd/SrTiO 3 catalyst was successfully prepared by the low-temperature plasma treatment coupling with photochemical deposition of metal Pd, which was applied to the photocatalytic degradation of toluene. Compared with single STO, STON, and Pd-STO catalysts, the prepared Pd-STON catalyst shows the excellent UV photocatalytic performance toward toluene degradation, realizing a ca.80 % degradation efficiency within 90 min reaction time. Based on various characterizations, it revealed that plasma treatment promoted the formation of surface oxygen defects, and strengthened the metal-support interaction. The resultant surface oxygen vacancy accelerated the migration rate of photogenerated electrons and the separation of electrons and holes in space, benefiting for superior performance. It is expected that this study can provide new avenues for the rational design of highly efficient photocatalysts for potential practical applications. [Display omitted] • The Pd/SrTiO 3 catalyst was prepared by plasma-induced coupling with photochemical deposition strategy. • Plasma-treatment promotes the formation of surface defects and strengthens the metal-support interaction. • The plasma-assisted Pd/SrTiO 3 catalyst exhibited superior performance for photocatalytic degradation of toluene. • Surface defects accelerated the transfer of photogenerated electrons and improved the separation of electrons and holes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Effect of plasma treatment and six different fluxes on solder wetting was studied. • Copper samples treated by N 2 /H 2 plasma exhibited excellent wetting with any flux. • Even expired fluxes can be successfully used for soldering of plasma-treated connectors. • Flux cannot be omitted from soldering due to the remaining thin oxide/organic layer. • Plasma treatment allows much less active flux to be used in the soldering process. To enhance the solderability, highly active fluxes are commonly employed in lead-free soldering. However, there are industry-wide efforts to use less active fluxes to avoid possible issues associated with corrosion processes and minimize subsequent cleaning processes, thereby reducing potential environmentally harmful waste. Therefore, in this study, the effect of the plasma treatment (N 2 /H 2 97:3) on the wettability of the soldered surface (copper connectors) was investigated. Wettability measurements were conducted using SAC305 solder alloy and six different fluxes. The wetting balance test revealed a significant improvement in wetting for all tested fluxes, regardless of their composition. On the other hand, non-wetting occurred when no flux was applied to the plasma-treated surface, attributed to a thin residual oxide layer detected by X-ray photoelectron spectroscopy. Thus, the plasma treatment of the surface supports the flux effect, which cannot be entirely omitted from the soldering process. However, incorporating plasma treatment in the soldering process allows for the use of much less active or even expired fluxes. [ABSTRACT FROM AUTHOR]

[Display omitted] • MnO-plasma treated VR-ACF removes Cu(II) and Cd(II) effectively. • Synergistic effect of plasma treatment and MnO coating enhances adsorption capacity. • KMnO 4 is the optimized oxidant, outperforming H 2 O 2 and Na 2 S 2 O 8. • Kinetic and column experiments unveil prolonged adsorption dynamics. • Plasma treatment can be a viable option to chemical surface modification techniques. This study investigates the enhanced removal of Cu(II) and Cd(II) heavy metal ions from water using viscose rayon based activated carbon felt (VR-ACF). Employing a synergistic approach involving oxidant (KMnO 4) and plasma treatment, the surface modification process was meticulously examined. Key findings demonstrate the superior efficacy of KMnO 4 over H 2 O 2 and Na 2 S 2 O 8 in coating. The synergy between plasma modification and 0.1 M KMnO 4 enhances VR-ACF's adsorption capacity, ensuring effective metal ion removal. Fine-tuning plasma parameters aids a comprehensive understanding of the modification process, guiding successful metal ion removal. Adsorption complexities are evidenced by prolonged kinetics of 720 min at pH 5 with high Q max of 175.43 mg/g for Cu(II) and 223.22 mg/g for Cd(II), and extended column experiments, affirming the efficacy of modified VR-ACF. Thermodynamic analyses underscore the spontaneity and variability of Cu(II) and Cd(II) adsorption. X-ray photoemission spectroscopy (XPS), Scanning electron microscopy (SEM), X-ray Diffraction (XRD) investigations endorse complexation, ion-exchange, co-precipitation, and solvation interactions. Recyclability tests reveal maintenance of 60% removal efficiency for five cycles, with reduced efficiency in the presence of phosphates and divalent cations. The 50% breakthrough time for adsorption of Cu(II) and Cd(II) was found to be 58 days and 62 days, respectively. This underscores the efficacy of modified VR-ACF in sustainable water purification, particularly in extended column setups, offering a hopeful path for advanced materials in eliminating heavy metal ions. [ABSTRACT FROM AUTHOR]

Solvent-free radiofrequency (RF) nitrogen plasma treatment was applied to incorporate nitrogen atoms in relatively high concentration. Graphene oxide (GO) and two reduced GOs of different O-content were used as target substrates to reveal the influence of the functional groups decorating the graphene lattice on the quantity and quality of nitrogen incorporation. Despite the relatively high oxygen content of the samples no N–O bonds develop but three kinds of different N–C bonds of very similar concentration are formed. Reduction of the GO removed the O-groups but did not heal the vacancies where N doping may occur. After two days the implanted N content drops, the N1 state (sp2 N in pyridine ring, C–N–C) showing the least stability. [Display omitted] [ABSTRACT FROM AUTHOR]

• KN95 and filtering face piece two masks were disinfected by atmospheric pressure cold plasma. • Nitrogen plasma treatment achieved the best bacterial inactivation. • Pseudomonas aeruginosa and Escherichia coli were inactivated mainly by the thermal effect. • Reactive oxygen and nitrogen species generated in plasma were the main cause of the Staphylococcus aureus antimicrobial effect. • Filtration capacity and breathability did not change after five cycles of plasma treatment. Mask usage has increased over the last few years due to the COVID-19 pandemic, resulting in a mask shortage. Furthermore, their prolonged use causes skin problems related to bacterial overgrowth. To overcome these problems, atmospheric pressure cold plasma was studied as an alternative technology for mask disinfection. Different microorganisms (Pseudomonas aeruginosa, Escherichia coli, Staphylococcus spp.), different gases (nitrogen, argon, and air), plasma power (90-300 W), and treatment times (45 seconds to 5 minutes) were tested. The best atmospheric pressure cold plasma treatment was the one generated by nitrogen gas at 300 W and 1.5 minutes. Testing of breathing and filtering performance and microscopic and visual analysis after one and five plasma treatment cycles, highlighted that these treatments did not affect the morphology or functional capacity of the masks. Considering the above, we strongly believe that atmospheric pressure cold plasma could be an inexpensive, eco-friendly, and sustainable mask disinfection technology enabling their reusability and solving mask shortage. [Display omitted] [ABSTRACT FROM AUTHOR]

A novel metal-free amperometric sensor based on O 2 /Ar plasma modified carbon nanowalls (CNW) was successfully developed for non-enzymatic detection of hydrogen peroxide (H 2 O 2). This study demonstrates the effectiveness of surface modification of CNW by O 2 /Ar plasma treatment to improve the electrochemical sensing performance. It was shown that the CNW treated in low oxygen flow rate (O 2 /Ar: 0.1/10sccm) exhibited the highest concentration of incorporated oxygen on its structure, which consequently resulted in conversion of intrinsic hydrophobicity of CNW to hydrophilicity. Interestingly, however, further increase in oxygen flow rate did not increase the oxygen content of CNW structure, but instead it resulted in an increment in the defect and contributing less oxygen on CNW surface. The highest amperometric response was observed for the CNW treated with O 2 /Ar: 1.0/10sccm, which has lower oxygen content than the CNW treated with O 2 /Ar: 0.1/10sccm, but still possessing hydrophilic characteristic as well as owning more defect sites. These results can suggest the importance of both defects and oxygen-containing functional groups in electrochemical behavior of the electrode as both defects and oxygen-containing functional groups can act as potential active sites for electrochemical reactions and oxygen-containing functional groups can enhance the hydrophilicity and surface area wetted by the electrolyte. The modified CNW exhibited the potential for quantification analysis of H 2 O 2 with a wide linear range covering from 50 μM to 28000 μM, a good sensitivity of 126.6 μA/mM.cm2 and a detection limit of 0.91 μM (S/N = 3). This study demonstrates the success in utilizing the CNW structure towards detecting of H 2 O 2 as a metal-free sensor. [Display omitted] [ABSTRACT FROM AUTHOR]

Utilization of 3D nanostructured Pt cathodes could obviously improve performances of proton exchange membrane fuel cells (PEMFCs) owing to the reduced tortuosity and the bi-continuous nanoporous structure. However, these cathodes usually suffer from the flooding problem ascribed to the ionomer-free and nanoscale pores which are more susceptible to water condensation. In this paper, ultra-thin nanoporous metal films (100 nm) were utilized to construct PEMFC cathodes and independent transport channels were designed separately for water and gas aiming at the flooding problem. Nanoporous gold (NPG) film was used as the model support for loading Pt nanoparticles owing to its controllable and stable structure. After optimizing the polytetrafluoroethylene (PTFE) content and carbon loading in the gas diffusion layer (GDL), plasma treatment under O 2 atmosphere was used to pattern the GDL with independent water transport channels. The obtained liquid permeation coefficients and oxygen gains demonstrated the obviously improved water and O 2 transport. By using a home-made optimized GDL and a nanoporous film cathode with pore size ∼60 nm, the flooding problem could be facilely solved. With a Pt loading of ∼16 μg cm−2, this 3D nanostructured cathode exhibits a PEMFC performance of ∼957 mW cm−2 at 80 °C. The Pt power efficiency is about 4 times higher than that of the commercial Pt/C cathode (50 μg cm−2, 756 mW cm−2). Obviously, this study provides a simple but effective methodology to solve the water flooding problem in the ultra-thin nanoporous film cathodes which is applicable for other types of 3D nanostructured PEMFC cathodes. Independent drainage channels are constructed by plasma patterning treatment, and the hydrophobic portion provides a transport channel for the reaction gas, which reduces the mass transfer resistance and improves performance compared to the disordered water-gas transport before optimization. [Display omitted] • O 2 -plasma treatment was used to fabricate hydrophilic surface. • Designing independent hydrophilic/hydrophobic surface separately for water and gas transport. • Constructing nanoporous ultra-thin cathode with outstanding PEMFC performance. [ABSTRACT FROM AUTHOR]

This study is to bring an overview on various methods regarding the surface treatment performed on different polymeric membranes in relation to a deference between the treatment mechanism and their chemical structure. Herein, plasma and UV surface treatments (PST and UST) were utilized to treat the surfaces of two commercial membranes, i.e., aromatic polyimide and polyethylene terephthalate for various durations using a discharge electrode and an UV LED curing system, respectively. Based on the effects of PST and UST processes on the surface of these membranes, their surface properties have been characterized to surface morphology and hydrophilicity (or wettability), at same time the changes have probably occurred on their surface during the PST and UST processes. As a result, their hydrophilic behavior was significantly enhanced after conducting these treatment processes based on the investigation of water contact angle. Moreover, Fourier-transform infrared and Raman spectroscopy manifested the changes in the chemical bonds, interactions and orientations of molecules, which confirmed the apparition and insertion of polar functional groups after the surface treatments, and accordingly, their wettability was enhanced significantly. Also, optical microscopy images showed direct impactions on their surface and the evidence of slight surface aging/damage during the treatment processes based on the presentation of the strange streaks on the treated surfaces. In particular, the peel forces exhibited an increase comparing to the initial membranes, which is characteristically for enhancing their adhesion behavior. Hence, these results are needful for improving the surface properties of a material, and obtaining better adhesion behavior on the membrane-like materials and recycling polymer materials. [Display omitted] • Plasma and UV surface treatments were utilized to treat surfaces of aromatic polyimide and polyethylene terephthalate for various durations. • Characterization of treated surface of both polymeric membranes was also investigated. • A 90° peel test was also used to character the adhesion behavior of treated membranes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Soft-chemistry plasma approach for surface tuning of cellulose nanofilms. • Cellulose nanofilms preserved bulk microcrystalline properties after plasma thinning. • Broadband THz-TDS reveals many spectral features in the 1.5–14.5 THz range. • Evaluated the CNF thickness requirements for desired THz attenuation. For the extended ultra-wideband THz band up to 10 THz and beyond, materials with different functional properties are required. In addition, the THz shielding devices require the desired thickness for different shielding effects, which can be tailored by the surface functionalities. Here, a plasma-assisted soft chemistry approach was used to tailor the cellulose nanofibrils (CNFs), and the effects of plasma surface treatment were investigated using non-destructive terahertz time-domain spectroscopy (THz-TDS). CNFs with three different thicknesses were investigated as a function of mild and strong plasma treatment. The ultra-broadband THz-TDS evaluation of CNF films overcomes the challenge by surpassing the conventional low-frequency THz-TDS measurements and reveals many characteristic THz features of CNF at 2.1, 3.1, 5.1, 7.0, 10.3 and 10.9 THz. THz-TDS analysis indicates thinning of CNF after plasma treatment due to the plasma etching effect. At the same time, the microcrystalline properties of the CNF samples remain intact even after significant surface modification under plasma carbonisation conditions. Apart from this, the studies proposed the required minimum thickness for THz shielding applications based on the optical parameters and THz properties derived from the plasma-treated CNF structures, which could be used to define the thickness of sustainable shielding materials for THz devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • Plasma treatment enhances the adsorption of antimicrobial agents on wool fibers. • The MPZ-Fiber antibacterial coating has stable and robust antimicrobial efficacy. • The antibacterial and mothproof coating offers high load capacity and thermal stability. • Wool after surface modification exhibits durable preservation effects. The increasing focus on sustainable and eco-friendly materials has sparked a growing interest in wool as a natural fiber for sustainable fashion, thanks to its skin-friendly properties, warmth, breathability, renewability and biodegradability. The advancement of wool fabrics with durable antimicrobial and moth-resistant qualities could significantly enhance the utilization of wool in the production of high-quality textiles. This study investigates the synthesis of M−Arg and polyhexamethylene guanidine hydrochloride (PHMG) and their application in the surface modification of wool fibers, with an evaluation of the antimicrobial properties of the treated fabrics. Initially, plasma was used to pre-treat the wool fibers, followed by the adsorption of M−Arg and PHMG and ZnO in situ on the fibers' surface. The antibacterial effectiveness against gram-positive (Staphylococcus aureus, S. aureus) and gram-negative (Escherichia coli, E. coli) microorganisms was assessed through antibacterial testing of the M−Arg/PHMG/ZnO-Fiber (MPN-Fiber). Results showed that the MPN-Fiber exhibited a significantly higher antimicrobial rate compared to untreated wool fiber. The prepared MPN-Fiber inhibited E. coli and S. aureus by 99.64 ± 1.04 % and 96.47 ± 2.14 %, respectively. Additionally, the MPN-fiber has good washing resistance (20 times, lose only 10 %). The experimental results clearly demonstrated that the MPN-Fiber exhibited exemplary antibacterial and moth-proof properties, confirming the success of the innovative surface modification approach. [ABSTRACT FROM AUTHOR]

High-performance electrostatic capacitors are urgently needed of advanced electronic devices. Traditional nanodielectric designs, such as polyvinylidene fluoride (PVDF)-based nanocomposites with uniformly distributed nanofillers, necessitate laborious filler interface modification and yield limited energy density (U e) and efficiency (η). Herein, boron nitride nanosheet (BNNS) intercalated polymer nanocomposites were innovatively prepared by plasma treatment and BNNS spatially-confined self-assembly techniques. The oriented dense interlayered BNNS substantially suppresses leakage current and bolsters the breakdown strength of nanocomposite films, outperforming randomly or oriented distributed BNNS systems, thus obtaining a higher U e of ∼24.1 J/cm3. Moreover, the relaxation loss of PVDF could be effectively mitigated by polymethyl methacrylate and trace intercalated BNNS, maintaining an ultrahigh η (76 %) at 600 MV/m and greatly enhances the energy storage performance. Significantly, this newly designed nanocomposites necessitate only traces of BNNS (0.2 wt%) without filler-surface-modification. These findings afford insight into the programming and manufacture of high-performance electrostatic capacitors. Trace introduction of BNNS interlayer via plasma treatment and BNNS spatially-confined self-assembly technology to significantly enhance the energy storage performance of nanocomposite. [Display omitted] • Plasma treatment and spatially-confined self-assembly create PMB-i with dense BNNS. • Using merely 0.2 wt% BNNS without complex mods, streamlining capacitor production. • Optimized PMB-i shows enhanced energy storage (600 MV/m, 24.1 J/cm3, 76 %) vs PVDF. • Excellent stability and fast charge-discharge enable further dielectric development. [ABSTRACT FROM AUTHOR]

Plasma treatment is a crucial technique for manipulating the optoelectronic properties of ZnO devices by modifying surface defects. The choice of plasma gas in the treatment process significantly influences these defects, as evidenced by the luminescence characteristics. In this paper, significant differences have been observed in the photoluminescence spectra of ZnO films and single crystals before and after treatment with three kinds of plasma gas. After Ar and H plasma treatment, the UV emission is significantly enhanced up to 1000 times, while the visible emission is suppressed. Conversely, after O plasma treatment, the UV emission remains unchanged, but the deep level emission exhibits a subtle transformation. Since the influence depth of plasma treatment is confined to the surface, all these alterations of typical luminescence are strongly dependent on surface-related defects, thereby challenging the previous interpretation that they originate from bulk defects. The modification effects of various plasmas on surfaces are confirmed from multiple perspectives, and the mechanisms behind the enhancement or suppression of luminescence are systematically analyzed. A comprehensive understanding of plasma treatment, along with precise control of surface defects, is crucial for optimizing the performance of ZnO devices. [ABSTRACT FROM AUTHOR]

With the development of power system, high-speed railway and electric vehicles, insulations face accelerated challenges from higher voltage, harsh natural conditions and unexpected erosions, which puts forward higher requirements for complicated performance of insulation materials. In this study, an adjustable and scalable surface functionalizing method based on surface dielectric barrier discharge (SDBD) plasma was developed to fabricate surface functionally gradient materials (SFGM) of epoxy resin (EP) insulation, and further improve its comprehensive insulating performances. It is demonstrated that the typical Ar/Polydimethylsiloxane (PDMS)/SDBD plasma drives functionally gradient reactions consisting of attenuated fragmenting, grafting and crosslinking on EP surface, thereby fabricating SFGM with continuous gradient physical morphologies and chemical compositions. Results show that the low addition of PDMS leads to the thin film deposition with small particles, in contrast, the excessive addition of PDMS suppresses plasma discharge and leads to the low cross-linked Si O 2 film deposition, which both hinder SFGM performances. Through regulating the addition of PDMS, the optimal plasma discharge is motivated and the optimal Si-O 3–4 insulating surface of SFGM that displays stable super-hydrophobicity, moderate charge migration and the highest flashover voltage is fabricated. Furthermore, based on multi-dimension characterization and analysis, the plasma-driven surface gradient reactions and the effect of reaction medium on material performance are clearly clarified, which provides a scalable fabrication technique and provides guiding insights into the tailoring of insulating materials in industry. [Display omitted] • Plasma-assisted surface coating based on fragmenting, grafting and crosslinking of siloxane medium • Fabrication of continuous surface functionally gradient materials through attenuated reactions • Improvement of comprehensive insulating performances for multiple targets • More effective, eco-friendly and scalable compared to common surface coating methods [ABSTRACT FROM AUTHOR]

• SERS substrates are fabricated by plasma treatment of Ag-deposited glass slides. • Without analytes, the substrates contain barely observed SERS hot spots. • Dropping liquid samples on the substrates causes many analyte-induced hot spots. • Number of analyte-induced hot spots is strongly correlated to sample concentration. • The correlation greatly enhances SERS ability to distinguish sample concentrations. Surface-enhanced Raman scattering (SERS) is commonly used for material detection but usually exhibits low sensitivity to concentration changes. Here, we propose a novel method based on analyte-induced hot spots to enhance its sensitivity. SERS substrates were prepared by thermally depositing silver onto glass slides, followed by plasma treatment in a mixed atmosphere of air and oxygen. This treatment altered the silver morphology, increasing the separation between Ag nanoparticles (AgNPs) and initially inhibiting hot spot formation. Consequently, the substrates exhibited low SERS efficiency due to limited hot spot development. Interestingly, upon introducing an aqueous analyte onto the substrate, AgNP aggregation occurred, leading to the formation of numerous hot spots that showed a positive correlation with analyte concentration. This positive correlation significantly enhanced SERS sensitivity to concentration variations. The proposed technique effectively distinguishes adenine analytes, demonstrating a twofold difference across a concentration range of 2 × 10−6 to 2 × 10−4 M, supported by non-overlapping error bars in the SERS signals. Our research introduces an innovative method that utilizes analyte-induced hot spots to significantly enhance SERS effectiveness in distinguishing between different concentrations of chemical solutions. This advancement represents a significant step forward in achieving precise quantitative SERS detection. [Display omitted] [ABSTRACT FROM AUTHOR]

The plasma-silane coupling agent synergistically modified the hollow glass microsphere (HGM) process, blended with epoxy resin (EP), to prepare an acoustic matching layer suitable for the gas ultrasonic transducers. In comparison to the traditional NaOH solution stirring co-hydroxylation process, the plasma treatment method can rapidly activate the surface activity of HGM, leading to the generation of a large number of hydroxyl groups on the HGM surface. This process eliminates the need for mechanical stirring and cleaning steps, thus reducing the damage degree of HGM and the loss degree of surface hydroxyl groups. The results indicate that the amination modification effect of HGM treated with plasma is more pronounced, and the HGM/EP composite material exhibits better compatibility and density. The assembled ultrasonic transducer exhibits a sensitivity of up to 1.58 V, showing an improvement of nearly 61.2 % compared to the reference ultrasonic transducer with a sensitivity of 0.98 V. Furthermore, the calibrated testing of the gas ultrasonic flowmeter using the improved ultrasonic transducer demonstrates a percentage error absolute value below 0.7 % and a measurement result standard deviation below 0.15 %, demonstrating better measurement accuracy and consistency. This study aims to provide a new feasible process for improving the performance of gas ultrasonic transducers and ultrasonic flowmeters. [ABSTRACT FROM AUTHOR]

The degradation of chlorine-containing volatile organic compounds (CVOCs) catalytic combustion technology is subject to the catalyst chlorine poisoning, which is resulted from the chlorination of active phases, even though the structural stable perovskite. The reaction between Ca species and dissociated chlorine species is demonstrated as an efficient way to inhibited chlorine poisoning of the active phase. Herein, a Ca substituted partial La prepared La 0.8 Ca 0.2 MnO 3 (named as L8C2MO) perovskite was treated by 5% H 2 /Ar plasma driven route (the treated sample was denoted as L8C2MO-P), which was applied for the chlorobenzene oxidation removal. The integrated characterization results of XRD, XPS, HRTEM, etc. confirmed that Ca (mainly exhibited as CaCO 3) was successfully exsolved from La 0.8 Ca 0.2 MnO 3 and simultaneously leaved oxygen vacancies on the surficial layers. The continuous catalytic oxidation experiments illustrated that the conversion efficiency of L8C2MO was unexpectedly decreased compared with that of LaMnO 3 (LMO in short) sample, while that of L8C2MO-P was nearly maintained the oxidation capacity, with approximately 12 °C of 90% chlorobenzene conversion temperature (T 90) higher than that of LMO. Importantly, the CO 2 and inorganic chlorine species yields were significantly enhanced for L8C2MO and L8C2MO-P. The characteristic of used samples showed a possible chlorinated Ca species formation while the status of Mn phases was hardly changed, suggesting the exsolved Ca could inhibit the poison of Mn sites by binding with dissociative chlorine species. Additionally, oxygen vacancies that generated along with Ca exsolution process was definitely contributed to the deep oxidation of chlorobenzene. The possible reaction route was also studied by in situ DRIFTS and GCMS. The work provides a potential route as in situ growth of adjacent sites to protect active phases from chlorine poison in CVOCs catalytic oxidation process. [Display omitted] • Ca was successfully exsolved from La 0.8 Ca 0.2 MnO 3 by rapid plasma driven route. • Simultaneously oxygen vacancies created on the surface after Ca exsolution. • The exsolved CaCO 3 acted as the adsorption sites to prevent the Mn poison from dissociative chlorine. • High mineralization was obtained during chlorobenzene catalytic oxidation. • The exsolution route and reaction mechanism was proposed over prepared catalyst. [ABSTRACT FROM AUTHOR]

Thermal properties and durability make polyurethane (PU) ideal for conveyor belts in food processing industry. On the other hand, its susceptibility to adhesion of pathogens subjects him to surface treatment techniques. In this study, substrates of PU were exposed to corona discharge using air as treatment gas. The process parameters, such as treatment time and nozzle-substrate distance, and the microbicidal effects of the polymer surfaces against Staphylococcus aureus and Escherichia coli were examined. Changes in surface hydrophobicity occurred at short treatment times due to the introduction of polar groups, as proofed by X-ray Photoelectron Spectroscopy (XPS), while the surface morphology suffered minor changes as revealed by Scanning Electron Microscopy (SEM) imaging. Moreover, the hydrophilicity of plasma treated PU was minimal affected by the variation of nozzle-substrate distance, as long as the discharge was in contact with the polymer surface. The hydrophilic surfaces developed a very good resistance to bacteria adherence in few hours after incubation. • Corona discharge can create conveyor belts with antibacterial properties to ensure microbiological safety in food processing industry. • Corona discharge can change polyurethane surface chemistry and preserve its morphology. • The hydrophilic surfaces developed a very good resistance to bacteria adherence in few hours after incubation. • Environmentally friendly application compared to conventional procedures contains chemical agents. [ABSTRACT FROM AUTHOR]

The impact of Ar or O 2 plasma treatment on the electrical characteristics of SnGaO thin film transistors (TFTs) fabricated via solution method was examined. The findings of the study revealed that Ar plasma treatment for an optimal duration enhances the electrical properties of SnGaO TFTs, including the improvement of mobility, subthreshold swing (S·S.), and on-off ratio. This result is considered to be due to the increased concentration of oxygen vacancy as donor in the channel layer. Oxygen plasma treatment has an opposite effect on the change in oxygen vacancy concentration, thereby reducing the off-state current and facilitating the adjustment of threshold voltage. However, excessive Ar or O 2 plasma treatment duration led to an increase in deep defect states and a significant "hump" phenomenon in the output characteristic curve. • The impact of Ar/O 2 plasma treatment on the electrical characteristics of SnGaO TFTs was examined. • Ar Plasma treatment for an optimal duration enhances the electrical properties of SnGaO TFTs, including the improvement of mobility, subthreshold swing (S·S.), and on-off ratio, which is considered to be due to the increased concentration of oxygen vacancy as donor in the channel layer. • Oxygen plasma treatment has an opposite effect on the change in oxygen vacancy concentration, thereby reducing the off-state current and facilitating the adjustment of threshold voltage. • Excessive Ar/O 2 plasma treatment duration led to an increase in defect states and a significant "hump" phenomenon in the output characteristic curve. [ABSTRACT FROM AUTHOR]

[Display omitted] • Oxygen plasma etching method was developed for controllable carbonylation. • E-CNTs exhibited an outstanding performance in the degradation of 2,4-DCP. • The contribution of singlet oxygen increased from 9.8% (CNT) to 54.9% (EC30). • A binary linear correlation was constructed between K with O and D (R 2 = 0.92). A facile oxygen-plasma strategy was used to engineer carbon nanotubes (CNTs) surface with defects and carbonyl groups for organic water decontamination. The plasma-treated CNTs (E-CNTs) displayed a remarkable efficacy to catalyze peroxymonosulfate (PMS) activation for degrading electron-rich pollutants across a broad range of pH levels and under natural water conditions. Moreover, the kinetic constant for E-CNTs was found to be 4.1 times that of raw CNTs, attaining 97 % 2,4-DCP degradation in 20 min. The in situ capturing by electron paramagnetic resonance, chemical probing, and selectively scavenging tests collectively reveal that singlet oxygen (1O 2) was the dominant reactive species with 54.9 % contribution to 2,4-DCP removal. The structure–activity relationship analysis and density functional theory (DFT) revealed that defects and carbonyl groups were the intrinsic catalytic sites for PMS activation. A comprehensive degradation pathway was proposed based on the properties of pollutant and degradation products from HPLC-MS and DFT calculations. Based on the ECOSAR analyses, the toxicity of the treated water (degradation intermediates) dramatically declined except for a polymerized bipolymer TP6 (m / z = 266.9). This article provides a novel method to create PMS-oriented active sites on carbon materials for selective singlet oxygen production and water purification. [ABSTRACT FROM AUTHOR]

[Display omitted] • Successfully synthesizing BiOBr-BiOI heterojunctions using the solvothermal method. • Study of the effect of BiOBr-BiOI proportion on characteristics of the resultant samples. • Plasma treatment of BiOBr-BiOI photocatalyst with improper proportion. • Boosting the MB degradation by plasma-treated photocatalyst with improper proportion. • Study of plasma treatment factors on the performance of the treated photocatalysts. In this work, BiOBr-BiOI nano photocatalysts with different ratios were synthesized and evaluated under simulated sunlight for the removal of methylene blue (MB). BiOBr-BiOI with a 1:3 ratio removed 97 % of methylene blue, which was the highest removal percentage among the studied samples. The as-prepared photocatalysts were analyzed by XRD, BET-BJH, FESEM, UV–Vis DRS, and PL techniques. According to XRD, in all samples, BiOI and BiOBr crystals were present and the formation of a heterojunction was confirmed. FESEM indicated that the nanolayers of BiOI and BiOBr have been agglomerated in the form of flower-like micronized spheres. DRS analysis showed that BiOBr-BiOI (1:3) had a bandgap energy of 2.46 eV, between the bandgap energies of BiOBr and BiOI. To determine the suitable operating conditions, various operational parameters were examined using BiOBr-BiOI (1:3) and it was found that photocatalyst loading of 1 g/L, initial MB concentration of 5 ppm, and pH = 7, led to the maximum MB conversion. In the next phase, BiOBr-BiOI (1:1), which had the least activity in the degradation of MB, was subjected to plasma to investigate the effect of plasma on photocatalysts with ill-defined structure and low activity. Different voltages as well as different discharge durations were applied to this sample. Analyses confirmed that the size of the clusters, and the roughness of surfaces have declined after plasma treatment. Moreover, plasmonic Bi particles were formed which enhanced the light absorption and decreased charge carrier recombination which all resulted in a rise in the MB photocatalytic conversion from 40 % to 93 %. [ABSTRACT FROM AUTHOR]

The plasma treatment of graphene oxide (GO) is a promising method for safely carrying out the surface modification of GO because the treatment can be performed at room temperature without the use of toxic processing gases. In this study, plasma reduction and nitrogen doping were carried out on GO, and the chemical property of the treated GO were investigated in detail, thereby demonstrating the superior properties of plasma treatment. Unlike thermal reduction, in which epoxide and hydroxyl groups were preferentially removed, plasma reduction removes all types of functional groups, thus realizing a novel form of modified GO surface. Since the functional groups might behave as an active site for doping, its relative abundance during the nitrogen plasma treatment of GO at room temperature resulted in a large amount of the nitrogen content (up to 19.1 at%). These characteristics of plasma-assisted GO treatment are expected to improve the device performance and can open up new possibilities for GO applications. [Display omitted] [ABSTRACT FROM AUTHOR]

We investigated terahertz-infrared electrodynamic properties of wafer-scale films composed of plasma-treated single-walled carbon nanotubes (SWCNTs) and films comprising SWCNTs grown with different lengths. The spectra of complex conductance of the films were measured at frequencies 5–20 000 cm−1 and in the temperature interval 5–300 K. Terahertz spectral response of films of pristine SWCNTs is well described with the Drude conductivity model and a plasmon resonance located at ≈100 cm−1. Stepwise treatment of the films with oxygen plasma led to a gradual suppression of the Drude spectral weight from the low-frequency side. For films with the nanotubes shorter than 1 μm, i. e., close to electrons mean free path and localization length, scattering of charge carriers at the nanotubes edges is shown to additionally contribute to the carriers scattering rate and to the damping of plasmon resonance. The temperature coefficient of ac resistance (ac TCR) in both kinds of films is found to strongly increase in amplitude during cooling and frequency decrease. The values of ac TCR increase in films with longer time of plasma treatment and nanotubes with shorter length but reach saturation in films with exposure time longer than ≈100 s or composed from SWCNTs shorter than 1 μm. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel MOF, BIT-72, was synthesized and modified by plasma of N 2 and O 2. • MMM were fabricated with BIT-72 and plasma modified BIT-72. • CO 2 /CH 4 and CO 2 /N 2 selectivity of 30.96 and 56.28 was achieved respectively with BIT-72 MMM. • CO 2 /CH 4 and CO 2 /N 2 selectivity was enhanced to 43.07 and 72.64 respectively with N 2 -BIT-72 MMM. • CO 2 /CH 4 and CO 2 /N 2 selectivity was enhanced to 37.28 and 66.21 respectively with O 2 -BIT-72 MMM. Gas separation membranes are a key development in eradication of harmful greenhouse gases such as carbon dioxide (CO 2). Different strategies have been utilized to enhance membrane performance and to overcome their drawbacks. In this study a unique approach has been utilized to enhance membrane performance. Initially mixed matrix membranes (MMM) were fabricated with a novel metal-organic framework (MOF), namely BIT-72 incorporated in Pebax®1657 matrix. At 30% loading of BIT-72, CO 2 /CH 4 and CO 2 /N 2 selectivities of 30.96 and 56.28 were achieved respectively with CO 2 permeability of 139 Barrer. To further enhance the performance of the MMM, BIT-72 was treated with plasma of N 2 or O 2 gases to prepare MMMs with same polymer (N 2 -BIT-72 MMM and O 2 -BIT-72 MMM, respectively). As a result, CO 2 /CH 4 and CO 2 /N 2 selectivity was enhanced to 43.07 and 72.64 respectively for N 2 plasma treated BIT-72 MMM (CO 2 permeability 146 Barrer) and for O 2 plasma treated BIT-72 MMM (CO 2 permeability 145 Barrer) CO 2 /CH 4 and CO 2 /N 2 selectivity was increased to 37.28 and 66.21 respectively. Plasma modified BIT-72 MMM showed promising results for further applications. [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) water splitting is one of promising green method to generated renewable energy such as hydrogen. To realize PEC for hydrogen production, it is indispensable to develop a high-performance photocatalyst. In this study, a facile surface engineering using plasma treatment is developed for TiO 2 nanotubes where the surface becomes porous and partially amorphized resulting in the enhanced photocatalytic activity. Moreover, electronic configuration of TiO 2 nanotubes were effectively modulated via ion plasma treatment, which improves charge transport and light-absorption in TiO 2 nanotubes. Electronic modulations in combination with the intriguing nanoporous structure after ion plasma treatment leads to significantly enhanced photocatalytic activity of TiO 2 nanotubes, which can be applied for designing next high-performance photocatalysts. A significance enhancement of photoelectrochemical water oxidation in alkaline solution is achieved for TiO 2 nanotube arrays via a facile surface plasma treatment. [Display omitted] • The ion plasma treatment can induce nanoporous surface structure of TiO 2 nanotube. • TiO 2 nanotubes after ion plasma treatment efficiently absorb visible light due to the modified electronic configuration. • Electronic and structural changes of TiO 2 nanotubes via ion plasma treatment can boost photocatalytic activity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Defects was created and morphology change was achieved on ZrO 2 support by plasma modification. • CoPt/ZrO 2 catalyst with extremely high cobalt dispersion (∼1 nm) were simply prepared. • The highly dispersed cobalt particles also had improved reducibility. • The combination of high cobalt dispersion and high cobalt reducibility resulted in higher FTS activity. A series of CoPt/ZrO 2 catalysts using plasma treatment to modify ZrO 2 support and/or to decompose the cobalt precusor were prepared. The nanostructure and properties of the supports and catalysts were characterized by N 2 -physisorption, SEM, TEM, XRD, XPS, H 2 -TPR and H 2 -TPD, and the catalytic performance of four catalysts was evaluated by Fischer-Tropsch synthesis (FTS) reaction. Characterization results showed that defects were created and morphology change was achieved on ZrO 2 support by plasma modification. The synegetic effect of plasma support modification and precursor decomposition resulted in extremely high dispersion of cobalt species (∼ 1 nm), these highly dispersed cobalt particles also had improved reduction ablibity, and thus a plentiful number of active sites were generated, despite its lower TOF value, a highest apparent FT activity was presented. [ABSTRACT FROM AUTHOR]

The top surface of carbon nanotube (CNT) "forests" produced by thermal chemical vapor deposition (CVD) often has a tangled morphology, owing to the self-organization of the CNTs at the initial stage of the CVD process. Removal of this top "crust" layer, without damaging the intrinsic microstructure of the CNT forest is often a key step for further applications. This paper studies the tailored use of Ar/O 2 plasma etching to modify the surface morphology of multi-walled CNT forests. First, we investigate the effects of process parameters including plasma power, flow rate, and gas composition on the etching of CNT forests. As a result, we identify the plasma conditions that successfully remove the top crust yet maintain the structural shape of a CNT forest. Second, we prepare CNT forests having different packing densities and heights to study the influence of the initial characteristics on the etching result. We experimentally confirm that the etching rate depends strongly on the density and morphology of the crust layer. We also compare the material removal rate in vertical and lateral directions. Finally, we explore the enhancement of alignment and chemical uniformity of the top surface of CNT forests by the Ar/O 2 plasma [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, Ni–Al spinel catalyst prepared with glycine-nitrate combustion method and treated by DBD plasma in different atmospheres have been investigated for propane steam reforming (PSR). It is revealed by H 2 -TPR that compared with traditional calcination method, NiO/Ni particles have much stronger interaction with the supports on the plasma-treated Ni–Al spinel catalysts. Therefore, catalysts with smaller NiO/Ni grains sizes, higher metallic Ni active surface areas can be achieved, as evidenced by XRD and H 2 adsorption-desorption measurements. NH 3 -TPD results demonstrate that the plasma treatment led to a decrease of the acidity of the Ni–Al spinel catalyst. Furthermore, larger quantities of surface active oxygen sites are also formed after plasma treatment, as testified by the O 2 -TPD and XPS results. As a consequence, the plasma-treated catalysts show significantly improved catalytic activities and coke resistance. Plasma treatment in H 2 /Ar atmosphere after calcination process is considered to be the best route to prepare NiAl 2 O 4 catalysts, which could be employed to obtain PSR catalysts with the highest catalytic activity and best anti-coking performance. It is believed that the higher metallic Ni active surface area and much more surface active oxygen sites induced by plasma treatment are the inherent reasons accounting for the enhanced catalytic performance of the Ni–Al spinel catalysts. [Display omitted] • DBD plasma treatment enhanced the interaction between NiO and Al 2 O 3 support. • Plasma-treated catalysts own both rich oxygen species and highly active Ni surface. • Plasma treatment led to a decrease of the acidity of the Ni–Al spinel catalyst. • Plasma treatment in H 2 /Ar after calcination process is found to be the best condition. • Both the catalytic performance and coking resistance of the catalysts are improved. [ABSTRACT FROM AUTHOR]

Dielectric barrier discharge (DBD) plasma applied as surface treatment technology was employed for the modification of Ag 2 O and graphitic carbon nitride (g-C 3 N 4) powders. Subsequently, the pretreated powders were sequentially loaded onto TiO 2 nanorods (TiO 2 -NRs) via electro-deposition, followed by calcination at N 2 atmosphere. The results indicated that at the optimal plasma discharge time of 5 min for modification of g-C 3 N 4 and Ag 2 O, photocurrent density of ternary composite was 6 times to bare TiO 2 -NRs under UV-visible light irradiation. Phenol was degraded by using DBD plasma-modified g-C 3 N 4 /Ag 2 O/TiO 2 -NRs electrode to analyze the photoelectrocatalytic performance. The removal rate of phenol for g-C 3 N 4 -5/Ag 2 O-5/TiO 2 -NRs electrode was about 3.07 times to that for TiO 2 -NRs electrode. During active species scavengers' analysis, superoxide radicals and hydroxyl radicals were the main oxidation active species for pollutants degradation. A possible electron-hole separation and transfer mechanism of ternary composite with high photoelectrocatalytic performance was proposed. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • PCL/CS nanofibers were electrospun, mimicking the aligned myocardial extracellular matrix. • Ar and N 2 DBD plasma treatments incorporated surface polar groups, enhancing cell adhesion. • Plasma-treated aligned fibers induced cardiomyocyte elongation and anisotropy. • The cell elongation was less pronounced on GeltrexTM-coated nanofibers. • Increased sarcomere distance and organization suggest cardiomyocyte maturation. Pluripotent stem cell (PSC)-derived cardiomyocytes offer vast potential in heart failure therapy, yet their immaturity poses challenges. To solve this issue, a multifaceted approach combining exclusive biochemical/topographical cues in the design of substrates mimicking the cardiac extracellular matrix was followed. Firstly, polycaprolactone (PCL)/chitosan nanofibers were electrospun in a random and aligned fashion, thus forming myocardium-like constructs. The scaffolds were then subjected to Ar and N 2 dielectric barrier discharge treatments, thus further improving their surface properties. The Ar plasma incorporated oxygen-containing functionalities onto the nanofibers surface with an additional implantation of nitrogen-containing groups upon N 2 plasma treatment, which both enhanced fibers' wettability. No topographical/dimensional damages were detected post-plasma treatments, except for a slight decrease in the surface roughness of the aligned nanofibers, which led to a decrease in their tensile stress. Both plasmas significantly enhanced the adhesion of PSC-derived cardiomyocytes that displayed more circular versus highly elongated body/nucleus morphologies on random versus aligned nanofibers, respectively. Interestingly, the cell alignment was less pronounced on GeltrexTM-coated nanofibers. Furthermore, increased sarcomere distance and organization were observed on aligned plasma-treated nanofibers, suggesting an enhanced cell maturation. Overall, PCL/chitosan nanofibers with aligned orientation and plasma-induced surface chemistry hold promise in cardiac tissue engineering applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • SnO 2 nanosheets assembled flower-like structures were prepared through hydrothermal method. • Oxygen vacancy content was modulated with argon-based plasma over different exposure durations. • Rich oxygen vacancies provided superior results for the sensor with 7 min plasma exposure. • The optimum sensor exhibits good sensitivity and prominent selectivity towards formaldehyde. Effective utilization of nanostructured metal-oxides with surface engineering is often overlooked during fabrication of gas sensors. The paper reports preparation of flower-like tin oxide nanosheets (average thickness = 12 nm) enriched with oxygen vacancies towards enhanced formaldehyde detection. The proportion of oxygen vacancy was increased using argon-plasma treatment (power = 100 W) with varied time durations (0, 2, 4, 7, 10 min). A detailed material characterization confirmed the structural property and oxygen vacancy content in the samples. A comparative sensing performance was analyzed among different fabricated sensor devices based on plasma exposure duration. Superior sensing behavior was registered from sensor S_7 comprising of sample with 7 min plasma exposure having maximum oxygen vacancy content of 53.16 % (relative). Sensor S_7 was considered optimum, which showed a response of 24.19 in presence of 10 ppm of formaldehyde which was 8.6 times greater than the sensor (S_0) without plasma exposure. Remarkably, sensor S_7 exhibited high sensitivity, fast kinetics, excellent reversibility, notable repeatability, and admirable selectivity, along with 34 ppb as limit of detection. Additionally, the sensing mechanism is adequately discussed based on the surface interaction, electronic sensitization and associated redox reactions. The demonstrated work emphasizes an efficacious approach toward developing upgraded gas sensor devices for widespread applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Antibacterial effect enhanced by plasma treatment against both gram-negative and gram-positive bacteria. • Photocatalytic effect enhanced by oxygen plasma treatment. • Surface roughness increased by plasma treatment. • Zinc ion release decreased by plasma treatment. • Surface charge influenced by plasma treatment. We characterize gallium-doped zinc oxide (ZnO:Ga) after exposure to hydrogen or oxygen plasma for potential use as a novel antibacterial and photocatalytic material. ZnO:Ga were composed of smooth rods with a thick central portion and tapered nanometre-sized ends alongside clusters of thin disk particles. Plasma treatment removed material from the rod surface and introduced features such as small holes or pits that increased the surface roughness and reduced the zinc ion concentration measured from colloidal suspensions. The surface charge of ZnO:Ga was influenced by plasma treatment: hydrogen plasma induced a positive surface charge whereas oxygen plasma resulted in a negative surface charge. However, electrostatic interactions with negatively charged bacteria were not the predominant mechanism underlying the antibacterial effect of ZnO:Ga. Treatment with oxygen or hydrogen plasma enhanced the antibacterial effect of ZnO:Ga against gram-positive bacteria, yet only oxygen plasma caused an enhancement against gram-negative bacteria. The photocatalytic effect of ZnO:Ga was enhanced after oxygen plasma treatment but supressed by hydrogen plasma treatment. The results indicate that plasma treatment of ZnO:Ga can successfully alter material properties to provide enhancement of the antibacterial and photocatalytic effects, however the type of feed gas used should be carefully chosen based upon the desired application. [ABSTRACT FROM AUTHOR]

[Display omitted] • F atoms in the plasma-treated PTFE were substituted by H atoms. • XPS and ToF-SIMS confirmed the existence of H on the plasma-treated PTFE surface. • The C1s binding energies are linearly dependent on the number of substituted F atoms. • Functional groups on fluoropolymers are identified using ab-initio calculation results. • Ab-initio calculation results reveal functional groups on fluoropolymers. X-ray photoelectron spectroscopy (XPS) measurements and ab-initio calculations of the XPS chemical shift were performed to identify chemical species on plasma-treated polytetrafluoroethylene (PTFE) surfaces. The obtained C1s-XPS and O1s-XPS spectra confirmed the generation of oxygen-containing functional groups on plasma-treated PTFE surfaces. We investigated the effect of the substitution of F atoms in a CF 2 – chain by H atoms on the C1s core level binding energy in PTFE; our calculations showed that the C1s core level binding energy is linearly dependent on the number of substituted F atoms. This finding enables us to infer the number of substituted F atoms from the experimentally observed C1s-XPS spectra. We deconvoluted the experimentally observed C1s-XPS spectra of the plasma-treated PTFE surfaces using the calculated binding energies of various functional groups. It is impossible to reproduce the C1s-XPS spectra using the C1s core level binding energies of functional groups in the CF 2 – chain. However, they can be well reproduced by adding the calculated binding energies of the functional groups in the CH 2 – chain, indicating the substitution of the F atoms by the H atoms by plasma treatment. Furthermore, the time-of-flight secondary ion mass spectrometry confirmed the existence of H atoms on the plasma-treated PTFE surfaces. [ABSTRACT FROM AUTHOR]

• The UHMWPE fabric was modified by plasma treatment and polypyrrole grafting. • Low-velocity impact and residual compressive tests were conducted. • X-ray micro-computed tomography was used to quantify the microscopic void distribution. • Combined plasma treatment and polypyrrole grafting could improve the impact resistance. The physical–chemical method with plasma treatment and polypyrrole grafting was used to improve the low velocity impact resistance of the ultra-high molecular weight polyethylene (UHMWPE) fiber/epoxy laminates. The experimental impact force–time curves and impact force-central displacement curves were recorded. The microscopic void distribution of impact region was quantitatively counted by high-resolution X-ray micro-computed tomography (μCT). Then the residual compressive strengths for the laminates after low velocity impact were explored. Experimental results showed that the impact resistance and residual strength of the laminates treated by the combined plasma treatment and polypyrrole grafting were significantly improved by comparing with the plasma treatment alone, and the void fraction also reduced remarkably. In addition, the impact resistance with single physical plasma treatment method was more affected by the mixture ratio of nitrogen and oxygen. [ABSTRACT FROM AUTHOR]

[Display omitted] • Degradation of four PFAS in (waste)water was investigated in a hybrid nonthermal plasma-ozonation cascade reactor. • The PFAS degradation efficiency increased in the order of PFBA (11 %) < PFHxA (32 %) < PFOA 80 %) < PFDA (90 %) after plasma-ozonation treatment. • The reactions occurring in the plasma chamber are responsible for PFAS degradation. • Reductive species (such as e aq − and Ar+) are mainly responsible for PFAS defluorination. • Without additional ozone dosing, the ozonation chamber enhances ozone utilization efficiency (55%) in the degradation of bulk organics. The widespread use of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in the last century has caused serious pollution of water bodies around the world, threatening the health of humans and other organisms. In this work, a novel cascade reactor configuration, comprised of a dielectric barrier discharge (DBD) plasma chamber connected with an ozonation chamber was used to treat municipal secondary effluent loaded with several PFAS. The electrical energy per order (EE/O) for degradation of perfluorooctanoic acid (PFOA) and perfluorodecanoic acid (PFDA) amounts 180 and 100 kWh/m3, respectively. While the short-chain PFAS (perfluorobutanoic acid (PFBA), perfluorohexanoic acid (PFHxA)) were difficult to be degraded, i.e. degradation percentage < 32 % after 60 min, 80–90 % of the longer PFAS (PFOA and PFDA) were degraded within 60 min. The degradation of PFAS mainly occurred in the plasma chamber rather than in ozonation chamber. This is because that reductive species produced in plasma chamber, such as hydrated electrons (e aq −) and Ar+, played a direct role in defluorination, while oxidative species, including OH, O, O 2 −, 1O 2 , O 3 , and H 2 O 2 , has a very limited contribution for defluorination. Enhancing the utilization of reductive species is crucial to degrade PFAS. Perfluoroalkyl carboxylic acids (PFCA) generated during the plasma reactions may have a potential risk for environment. As such, further optimization should focus on full mineralization. This study provides an approach to solve the problem of PFAS-contaminated wastewater, which is of the importance to promote the application of nonthermal plasma technique in water treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • The TiO 2 photoanode enhanced the efficiency by a plasma-assisted doping process. • A facile doping process increased the carrier density or conductivity of TiO 2. • Fluorine doping cured reaction of the oxygen vacancies and enhanced the performance. • The theoretical calculation showed that sequential doping was efficient and stable. Clean hydrogen production technologies are in high demand as an alternative to fossil fuels in order to achieve a carbon–neutral society. One promising approach is photoelectrochemical water splitting, which uses sunlight as an energy source to produce hydrogen. In this study, we propose a strategy for achieving highly efficient photoelectrochemical performance in TiO 2 nanorods without the need for additional heterojunction or catalyst reactions. We introduce the plasma-assisted sequential doping process using H and F species to demonstrate highly efficient photoanode for water splitting. In the first stage, hydrogenated TiO 2 generated oxygen vacancies and interstitial H in the TiO 2 lattice structure, and in the second stage, fluorinated TiO 2 exhibited a sequentially cured reaction of oxygen vacancy resulting in enhanced photoelectrochemical performance. Furthermore, theoretical simulations revealed that the sequential doping process induced a stabilized reaction in F compared to direct doping without H plasma doping. This sequential doping strategy can be applied to a wide range of materials and applications, not just to enhance photoelectrochemical devices. [ABSTRACT FROM AUTHOR]

[Display omitted] • GO/G electrode material is developed for the electrochemical biosensing of miRNA-21. • GO/G/FTO platform offer wide linear range (10 fM ∼ 1 nM) and low LOD of 3.18 fM. • Developed GO/G/FTO serves as a promising tool for the early diagnosis of diseases. Development of an efficient technique towards the detection of miRNAs is highly significant for the timely diagnosis and prognosis of cancers. In this study, we utilized the chemical vapor deposition (CVD) technique to grow bilayer graphene (BLG) on copper foil and subsequently transferred the BLG to fluorine doped tin oxide (FTO) substrate via a facile wet transfer technique. The upper layer of the BLG was modified to graphene oxide (GO) with a low damage plasma treatment (LDPT) process to serve as a biomolecule receiving layer and the lower graphene layer (G) serves as an electron transport layer. The developed GO/G/FTO platform offers superior sensing ability towards the miRNA-21. The results demonstrated that the proposed GO/G/FTO substrate detect the miRNA-21 with a wide linear range (10 fM ∼ 1 nM), low limit of detection (3.18 fM), high sensitivity (0.6 mApM−1cm−2), selectivity and stability via the differential pulse voltammetry method. Additionally, the sensors can efficiently discriminate the target miRNA-21 from its complementary base mismatched counterparts. The proposed approach serves as an excellent tool for the early diagnosis of diseases. [ABSTRACT FROM AUTHOR]

[Display omitted] • Plasma is an effective approach to improve the PEC performance to produce H 2. • PEC performance has been associated with the improvement of surface wettability. • The hydrophilic surface might be linked to the presence of Sb–N bonds. • The Sb–N bonds increased wettability due to hydrogen bonds with water molecules. • N 2 and air plasma have resulted in the increase of roughness of the Sb 2 Se 3 surface. Semiconductor films based on Sb 2 Se 3 are a promising choice to be applied as photocathodes for H 2 generation via solar-driven water splitting. However, the surface of Sb 2 Se 3 is extremely hydrophobic, which considerably compromises its photoelectrochemical (PEC) performance. To tackle this issue and improve H 2 generation via light-driven water splitting, we have developed a plasma treatment approach and evaluated the effect of plasma type (i.e., plasma of N 2 and ambient air) and plasma exposure time. According to water contact angle measurements, the surface of the Sb 2 Se 3 films changed from hydrophobic to hydrophilic over increasing plasma treatment time, and that was noticed for both N 2 and ambient air plasmas. XPS analyses showed the formation of a new Sb–N bond on the surface of the plasma-treated Sb 2 Se 3 and this may have enhanced wettability since the N in the Sb–N bond has the propensity to form hydrogen bonds with water. The PEC analyses showed that the optimized plasma treatment condition (N 2 plasma for 20 s) of the Sb 2 Se 3 films delivered a substantial photocurrent density (j ph) value for HER of (–3.9 ± 0.3) mA cm−2 at −0.2 V RHE , i.e., corresponding to 3-fold increase compared to that of the untreated film. Based on additional physical and electrochemical characterizations, the improved PEC performance for HER was assigned to the combined contribution of enhanced wettability and enlarged ECSA of the plasma-treated Sb 2 Se 3 films. Overall, this work features a new and simple method based on plasma treatment to improve the wettability of those semiconductor films facing hydrophobicity and to enhance solar-driven water splitting. [ABSTRACT FROM AUTHOR]

• Long chain PFAS can be effectively removed in the falling film DBD system due to their high reactivity and interfacial adsorption. • The insertion of ether oxygen enhanced the rate constants of PFAS removal but hindered the defluorination process. • PFSAs demonstrated higher defluorination efficiency due to their susceptibility to electron attack. • Synergistic effects of electrons, OH• and NO 2 • are pivotal to PFAS decomposition. Non-thermal plasma emerges as a promising technology for per- and polyfluoroalkyl substances (PFAS) decomposition due to its notable efficacy and environmentally friendly characteristics. In this study, we demonstrated the efficacy of a falling film dielectric barrier discharge (DBD) system for the removal of 10 PFAS, including perfluoroalkyl carboxylic acids (PFCAs), perfluoroalkyl sulfonic acids (PFSAs) and hexafluoropropylene oxide (HFPO) oligomer acids. Results showed that compounds with fluoroalkyl chain length>4 were effectively decomposed within 100 min, with long-chain PFAS demonstrating more pronounced removal performance than their short-chain analogues. The superior removal but low defluorination observed in HFPO oligomer acids could be ascribed to their ether-based structural features. The integration of experimental results with density functional theory (DFT) calculations revealed that the synergistic effects of various reactive species are pivotal to their efficient decomposition, with electrons, OH•, and NO 2 • playing essential roles. In contrast, the degradation of PFSAs was more dependent on electron attack than that of PFCAs and HFPO oligomer acids. Significantly, the most crucial degradation pathway for HFPO oligomer acids was the cleavage of ether C O, whether through radical or electron attack. Furthermore, the demonstrated effective removal in various water matrices showed the potential of the plasma system for removing PFAS in complex aquatic environments. This study provided mechanistic insights into PFAS degradation behavior in plasma processes, and it underscored the vital influence of molecular structures on degradability, thereby contributing to the further development and regulation of plasma-based technologies for treating PFAS in water. [Display omitted] [ABSTRACT FROM AUTHOR]

Photocatalysis is limited by the high recombination rate of photogenerated e- and h+, but the piezoelectric effect can enhance the separation efficiency of charge carriers, so that the combining piezoelectric catalysis with photocatalysis is a highly promising approach for improving catalytic performance. In this study, aim to enhance piezo-photocatalytic performance, plasma treatment was applied to modify the surface of Bi 2 WO 6 to form oxygen vacancies. After plasma treatment, Bi 2 WO 6 exhibited a larger specific surface area, thinner thickness, narrower band gap, etc. These improvements have been confirmed to enhance the piezoelectric response of Bi 2 WO 6 , facilitate band bending and further improve the absorption of visible light, accelerate the separation of charge carriers, thus enhanced the piezo-photocatalytic activity. Consequently, utilization of plasma treatment had improved greatly the piezo-photocatalytic performance of Bi 2 WO 6 for the degradation of tetracycline hydrochloride. Impressively, plasma treatment promoted the generation of 1O 2 during the piezo-photocatalytic reaction, emphasizing the advantages of utilizing plasma treatment for improving the performance of piezo-photocatalysts. This work highlights the use of plasma treatment to increase active sites and induce vacancy defects on the surface of catalysts, which exhibit excellent piezo-photocatalytic degradation performance and show great potential in the field of environmental remediation. [Display omitted] [ABSTRACT FROM AUTHOR]

• CNWs treatment in the air atmosphere leads to the formation of most active sites. • Surface modification using air atmosphere can be used to improve the ORR characteristics of carbon materials. • Structural defects of samples before treatment also made a significant contribution to the obtained ORR characteristic. Carbon materials are of outstanding interest for use in energy sources. One of the latest achievements in improving their specific characteristics is the doping of carbon materials with various heteroatoms. However, the mechanisms that lead to improved performance remain unexplored. In this study, we investigated the influence of structural defects and incorporated heteroatoms on the oxygen reduction reaction (ORR) of highly oriented pyrolytic graphite and carbon nanowalls. Controllable modification in DC plasma in an atmosphere of nitrogen, oxygen and air was used for the incorporation of heteroatoms. We found that treatment in the air atmosphere leads to the formation of most active sites due to incorporation of heteroatoms and partial amorphization of material surface. The DFT calculations reveal these active sites can't be amplified by substitution to nitrogen atom due to insignificant sorption energy difference of *OOH group compared with undoped carbon. Existed material's structural defects and appeared after the treatment also make a significant contribution to the obtained ORR characteristics. Plasma-assisted treatment under air conditions can be used for carbon nanomaterials modification for ORR application. [ABSTRACT FROM AUTHOR]