This study employed argon plasma technology for the surface modification of Ni-MOF-74, systematically investigating the influence of different treatment durations on the material's structure and catalytic performance. It was found that Ni-MOF-74 (Ar 120 s) exhibited an outstanding synergistic effect in the plasma-catalytic synthesis of ammonia. The ammonia synthesis rate increased to 10.77 mmol & centerdot;g-1 & centerdot;h-1, with a nitrogen conversion rate of 0.4% and an energy yield of 1.54 g & centerdot;kWh-1, representing a 1.9 times improvement compared to the pristine sample. Density functional theory (DFT) simulations revealed the mechanism of plasma-induced defect formation at the electronic structure level, clarifying the structure-activity relationship between material modification and catalytic performance.

To achieve high-precision and low-damage etching processes in semiconductor manufacturing, this study employs a capacitively coupled plasma etching system incorporating a grounded aluminium aperture plate to realize efficient radical-dominant etching process. Etch rates of poly-silicon (poly-Si), silicon nitride (Si3N4), and SiO2 were evaluated using CF4/O2/He as the discharge gas. A systematic investigation was conducted on the effects of radio-frequency power, working pressure, and gas flow rates on the etch selectivity and surface roughness, comparing radical etching with reactive ion etching (RIE). Optical emission actinometry was employed to in-situ quantify the relative density of fluorine (F) atoms, and to elucidate their correlation with etch selectivity. Results demonstrate that the aperture-plate configuration achieved an ion-filtration efficiency of up to 99.9999%, effectively suppressing ion-induced surface damage. Under the optimized radical-etching conditions (200 W discharge power, 40 Pa gas pressure, and 150/30/20 ml min-1 CF4/O2/He flow rates), the relative density of F reached 3.11 & times; 1013 molecule cm-3, enabling high etch selectivity of 66 for poly-Si/SiO2 and 26 for Si3N4/SiO2. Moreover, the surface roughness of the samples for radical etching was significantly superior to that obtained in RIE mode. These results confirm that tailoring plasma composition through an aperture-plate configuration is an effective strategy for achieving highly selective and low-damage etching, providing significant potential for the advancing etching process.

The escalating atmospheric CO2 concentration driven by fossil fuel consumption underscores the urgent need for efficient carbon capture and utilization technologies. This study focuses on the catalytic hydrogenation of CO2 to methane via the Sabatier reaction, employing a nickel-based catalyst supported on calcium carbonate (CaCO3) prepared by solution combustion synthesis (SCS). The SCS-derived Ni/CaCO3 catalyst exhibits exceptionally lowtemperature activity, achieving 89.4% CO2 conversion and 98.3% CH4 selectivity at 275 degrees C, along with remarkable stability over 30 h. Comprehensive characterization reveals that the SCS method facilitates the formation of a porous structure, enhances metal dispersion, and generates abundant oxygen vacancies and basic sites, which collectively promote CO2 adsorption and activation. In situ DRIFTS analysis further elucidates the reaction pathway involving carbonate, formate, and carbonyl intermediates. This work demonstrates the great potential of CaCO3-supported catalysts synthesized via SCS for efficient and sustainable CO2 methanation.

Graphene has attracted extensive attention due to its outstanding electrical, thermal, and mechanical properties, showing broad application prospects in flexible electronic devices, transparent conductive films, sensors, energy storage, and functional composites. To address the controllable synthesis of graphene, Ni3Cx thin films were deposited by plasma-enhanced atomic layer deposition (PEALD) using Ni(tBu2amd)2 as the precursor. Combined with subsequent Ni overlayer deposition and thermal annealing, the annealing-induced structural evolution of the Ni3Cx-containing system and the associated graphene-formation behavior were systematically investigated. The results show that under deposition conditions of a precursor pulse time of 5 s, purge time of 10 s, H₂ plasma exposure time of 10 s, plasma power of 60 W, and deposition temperature of 95 °C, Ni3Cx thin films prepared by 400 PEALD cycles and subsequently coated with a 71.5 nm Ni layer by magnetron sputtering exhibited particle size and elemental distribution more favorable for graphene growth after annealing at 900 °C, which was more conducive to the formation of high-quality graphene with Raman characteristics consistent with a bilayer/few-layer structure. Raman mapping over a 50 × 50 μm2 area showed relatively continuous and consistent spatial distributions of I2D/IG and ID/IG within the examined region, supporting local spatial uniformity. These results provide a controllable route toward substrate-supported graphene formation based on PEALD Ni3Cx films and indicate potential for direct integration on insulating substrates after further optimization of metal removal and device processing.

In this work, plasma-assisted atomic layer deposition (ALD) was used to coat a uniform Al2O3 film on the COF surface to prepare COF/Al2O3 composites; subsequently, silver nanoparticles were loaded by a photoreduction method to obtain COF/Al2O3/Ag core-shell composites. Electrochemical impedance spectroscopy (EIS), Mott-- Schottky analysis, and photocurrent response tests were conducted on the two composites using an electrochemical workstation. The results show that the addition of the Al2O3 intermediate layer significantly reduces the interfacial charge transfer resistance, regulates the flat band potential and carrier concentration of the semiconductor, and enhances the separation efficiency of photogenerated carriers, making COF/Al2O3/Ag exhibit stronger and more stable photocurrent responses. This also indicates that intermediate layer engineering via atomic layer deposition provides a simple and efficient strategy for optimizing COF-based photoelectrochemical materials.

Tetracycline is one of the most widely used broad-spectrum antibiotics, and its continuous release into aquatic environments has become a serious environmental concern. Although metal–organic frameworks (MOFs) have demonstrated great potential for photocatalytic wastewater treatment, conventional synthesis methods generally suffer from long reaction times and limited capability for controllable defect engineering. To address these challenges, a needle–plate pulsed discharge plasma strategy was developed for the direct synthesis of MIL-53(Fe). The effects of key plasma discharge parameters on the structure, defect structure, and photocatalytic performance of MIL-53(Fe) were investigated. Under the optimized conditions (6.2 kV, 120 min, an FeCl3/TPA molar ratio of 1:1, and Ar atmosphere), the obtained MIL-53(Fe) catalyst achieved an average tetracycline degradation efficiency of 91.57% within 120 min. Structural and photoelectrochemical analyses revealed that the obtained MIL-53(Fe) exists plasma-induced oxygen-vacancy-related defects while preserving the crystal framework of MIL-53(Fe). These defects promoted the separation and migration of photogenerated charge carriers, thereby significantly enhancing the photocatalytic activity under xenon-lamp irradiation. These findings demonstrate that needle–plate pulsed discharge provides an effective strategy for the controllable synthesis of defect-regulated MIL-53(Fe), offering new opportunities for developing high-performance photocatalysts for antibiotic-contaminated wastewater treatment.

Abstract To achieve high-precision and low-damage etching processes in semiconductor manufacturing, this study employs a capacitively coupled plasma etching system incorporating a grounded aluminium aperture plate to realize efficient radical-dominant etching process. Etch rates of poly-silicon (poly-Si), silicon nitride (Si 3 N 4 ), and SiO 2 were evaluated using CF 4 /O 2 /He as the discharge gas. A systematic investigation was conducted on the effects of radio-frequency power, working pressure, and gas flow rates on the etch selectivity and surface roughness, comparing radical etching with reactive ion etching (RIE). Optical emission actinometry was employed to in-situ quantify the relative density of fluorine (F) atoms, and to elucidate their correlation with etch selectivity. Results demonstrate that the aperture-plate configuration achieved an ion-filtration efficiency of up to 99.9999%, effectively suppressing ion-induced surface damage. Under the optimized radical-etching conditions (200 W discharge power, 40 Pa gas pressure, and 150/30/20 ml min −1 CF 4 /O 2 /He flow rates), the relative density of F reached 3.11 × 10 13 molecule cm −3 , enabling high etch selectivity of 66 for poly-Si/SiO 2 and 26 for Si 3 N 4 /SiO 2 . Moreover, the surface roughness of the samples for radical etching was significantly superior to that obtained in RIE mode. These results confirm that tailoring plasma composition through an aperture-plate configuration is an effective strategy for achieving highly selective and low-damage etching, providing significant potential for the advancing etching process.

High-quality few-layer graphene was successfully prepared on nickel-coated single-crystal silicon substrates by pulsed laser deposition, with systematic investigation on the effects of four key process parameters (deposition temperature, vacuum pressure, carbon film thickness, and nickel film thickness) on its structural properties. Multi-dimensional characterizations including Raman spectroscopy, X-ray diffraction, scanning electron microscopy-energy dispersive spectroscopy, X-ray photoelectron spectroscopy, atomic force microscopy, transmission electron microscopy, selected area electron diffraction, and Raman mapping were employed to clarify the growth mechanism and optimize process conditions. The results indicate that the optimal parameters are determined as 500 degrees C deposition temperature, 2.6 & times; 10-4 Pa vacuum pressure, 25 nm carbon film thickness, and 75 nm nickel film thickness. Under these conditions, the resulting graphene is a bilayer-dominated few-layer structure (local areas approaching single layers) with anI2D/IG ratio of 1.55-2.25 and a low defect density (ID/IG = 0.08-0.18), exhibiting excellent structural continuity, uniform layer distribution, and high crystalline quality.

As a clean and renewable energy source, hydrogen energy is produced via water electrolysis, making the development of efficient electrocatalytic materials essential. For the first time, this study employs lowtemperature plasma-assisted pulsed laser deposition to fabricate nickel nitride (Ni3N) thin films on monocrystalline silicon substrates. The effects of the nitrogen flow rate and laser power on the phase composition, microstructure and hydrogen evolution performance of the films in water electrolysis were systematically investigated. The film structures were characterized using X-ray diffraction, transmission electron microscopy and scanning electron microscopy, while their electrochemical properties were tested using a three-electrode system. The results show that the phase composition of the films is significantly influenced by the nitrogen flow rate. At 150 sccm, the Ni3N phase exhibits the optimal crystallinity with a dense surface. The laser power regulates the film growth kinetics, and the lowest surface roughness is achieved at 200 W. When the nitrogen flow rate is 150 sccm and the laser power is 150 W, the film demonstrates excellent catalytic activity: in 1 M KOH electrolyte, the overpotential at a current density of 10 mA.cm(-2) is only 120.4 mV, with a Tafel slope of 90.71 mV.dec(-1), reducing the overpotential by 53.8 % compared to pure nickel foam. This study optimizes the preparation process parameters, providing a theoretical and experimental basis for the design of highperformance nickel nitride electrocatalytic materials. The films exhibit excellent hydrogen evolution catalytic activity in alkaline electrolytes, showing promise for promoting the practical application of water electrolysis hydrogen production technology.

To address the challenges of high energy consumption and insufficient low-temperature activity in conventional thermal catalytic CO2 methanation, this study reports a new nickel-based catalyst preparation via the solution combustion synthesis (SCS) technique for plasma-catalytic CO2 methanation. The results demonstrate that the SCS method successfully reconstructed the CaCO3 support, resulting in a porous structure with a high specific surface area (23.86 m2/g) as well as highly dispersed Ni nanoparticles (approximately 9.32 nm), which significantly enhanced the metal-support interaction. Combined density functional theory (DFT) calculations and electron paramagnetic resonance (EPR) analysis revealed that the SCS-reconstructed CaCO3 surface is rich in oxygen vacancies, markedly enhancing the adsorption capacity for CO2 and CO (with adsorption energies reaching-3.83 eV and-3.56 eV, respectively), thereby providing favorable conditions for the intermediates formation for CO2 conversion. Under optimized conditions (3 wt% Ni loading, H2/CO2 ratio of 5, discharge power of 28 W, and gas hourly space velocity of 180,000 mL g-1 h-1), the CO2 conversion reached 79.1 % with a CH4 selectivity of 91.9 % and an energy efficiency of 17.2 %. These performance metrics are significantly superior to those of catalysts prepared by conventional impregnation methods and pure plasma systems. In situ characterizations (plasma DRIFTS and OES) indicated that the basic sites on CaCO3 preferentially adsorb CO2 to form carbonate species. The synergistic effect between high-energy electrons generated by the plasma and the Ni active sites promotes the hydrogenation of carbonates to formate intermediates, which are subsequently converted into CH4 via the formate pathway (HCOO* -> CO* -> CH4 or HCOO* -> CHO* -> CH4). The catalyst exhibited good stability during a continuous 24-h operation. This study provides a novel strategy for developing a bionic synergistic catalytic system for low-temperature and highly efficient CO2 conversion.

Optical emission spectroscopy is a powerful diagnostic tool for low-temperature plasma processes, yet the quantitative analysis of gas composition and pressure in mixtures remains challenging due to spectral line overlap and nonlinear effects. This study proposes a high-throughput analytical method based on a convolutional neural networks (CNN) to address this challenge. The method enables the simultaneous and accurate prediction of both gas composition ratios and total system pressure directly from a single emission spectrum of Ar/N-2/O-2 binary mixtures. A systematic dataset was constructed by collecting spectra under varied flow rates and pressures. An end-to-end CNN model was developed, and its performance was benchmarked against traditional machine learning methods, including random forest, support vector regression, and extreme gradient boosting. The CNN model demonstrated superior performance, achieving a test set root mean square error (RMSE) of <0.10 and R-2 of >0.70 for gas proportion prediction, and an RMSE of approximate to 0.13 with R-2 approximate to 0.70 for pressure regression. Interpretability analysis using Grad-CAM revealed that the high-importance wavelengths identified by the CNN align closely with the known characteristic spectral lines of the target gases. This alignment confirms the model's decision logic is physically interpretable and mitigates the "black-box" concern. The proposed CNN-based framework provides a reliable, efficient, and interpretable solution for intelligent online monitoring of plasma process parameters.

Single-atom catalysts (SACs) represent a promising solution for maximizing active-site utilization in exhaust gas elimination, yet the restricted functionality of isolated sites in competitive reaction kinetics often limits their performance. In this study, we present a photomediated strategy for the dynamic assembly of multifarious active sites on faceted CeO2. Combined experimental and theoretical analyses reveal that light-induced migration of Au atoms on 111-CeO2 transforms neighboring isolated Au atoms into nanoclusters, concurrently activating lattice oxygen near Au single atoms and molecular oxygen around Au nanoclusters. The dual active centers synergistically facilitate CO adsorption and oxygen dissociation of CO, enabling efficient room-temperature CO oxidation through a dual-path mechanism. The photoreconstructed active sites on 111-CeO2 exhibit remarkable catalytic performance, demonstrating 4-fold and 45-fold enhancement in reaction kinetics compared to conventional 111-CeO2- and 100-CeO2-based SACs, respectively, while surpassing state-of-the-art CO oxidation catalysts. This work provides atomic-level insights into metal-support interactions and establishes a novel approach for designing high-performance SACs for environmental catalysis.

Perfluorooctanoic acid (PFOA), a synthetic chemical, has been widely used in industrial applications due to its chemical stability and surface activity. However, its persistence in aquatic environments poses significant ecological risks. This paper reports a highly efficient defluorination method for PFOA in artificially polluted water using a strip fountain dielectric barrier discharge (DBD) synergized with peroxymonosulfate (PMS). The degradation rate and defluorination rate of PFOA nearly reach 99.2 % and 96.96 %, respectively, when 20.8 mmol/L PMS was added, compared to 90.33 % and 61 % under DBD plasma treatment alone. The enhanced performance is attributed to the synergistic generation of reactive oxygen species, including center dot H, center dot O, center dot OH, H2O2, H2, O2, O3. Radical scavenging experiments reveled that center dot OH plays a dominant role in defluorination, while center dot O2- and 1O2 also contribute significantly. And center dot OH was confirmed by electron spin resonance (ESR). Additionally, combining experimental data with density functional theory (DFT) calculations, possible degradation pathways of PFOA were deduced. This work demonstrates that DBD-PMS system is a promising energy-efficient technology for PFOA treatment.

In this study, 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20), 2,4,6-trinitrochlorobenzene (TNCB), and 2,4,6-trinitrotoluene (TNT) were sensitively detected with the aid of alkali ions (Li+, Na+ and K+ from the corresponding nitrate salts) using surface-enhanced Raman scattering (SERS), through an extremely simple process of adding explosive compounds and alkali ions to negatively charged silver colloids. The results show that the quantitative SERS detection limit of CL-20 is 1 nM with the addition of Na+, whereas for TNCB and TNT, the corresponding detection limit can reach 0.01 nM adjusted using Na+ and K+, respectively. The possible mechanisms of the sensitive SERS detection of trace nitro-explosives (CL-20, TNCB, and TNT) with the aid of alkali ions (Li+, Na+ and K+) have been investigated by Density Functional Theory (DFT) calculations. Natural Bond Orbital (NBO) analysis of the optimized structures of CL-20, TNCB and TNT revealed that the O atoms on the nitro group of these explosives carry a relatively greater negative charge, which can be successfully coordinated with the alkali ions accompanied by an obvious energy release to form positively charged complexes. Subsequently, these complexes spontaneously approach the negatively charged silver colloid, creating more SERS active sites, thereby enhancing the Raman detection sensitivity.

Cr(VI), a hazardous heavy-metal pollutant found in wastewater, exerts detrimental effects on biological systems and the human body. Efficient photocatalytic reduction of Cr(VI) to Cr(III) using high-performance materials offers a viable approach for Cr decontamination. In the current work, defective UiO-66-(OH)(2) with enhanced photocatalytic activity was developed by plasma treatment. These defects not only triggered an expansion in mesoporous domains and increased the Brunner-Emmet-Teller (BET) surface area of the UiO-66-(OH)(2) system, thereby exposing more adsorption and photocatalytically active sites, but also created additional electron migration pathways, enhancing the separation of photogenerated e(-)/h(+) pairs. When subjected to an operating power of 15 W, chamber pressure of 20 Pa, and a 300 s treatment period, UiO-66-(OH)(2) exhibited a removal efficiency of 83%. This work explored a novel means of construction of a defective metal organic framework (MOF) and broadened the utilization of MOFs in the fields of the photoreduction of heavy-metal ions in water.

Perfluorooctanoic acid (PFOA), as a pollutant, is widely distribution in the environment. Owing to its stable C-F bond and high toxicity, PFOA seriously threatens ecological and biological health. In this paper, threedimensional (3D) gliding arc plasma discharging in gas-liquid phase is used to degrade PFOA in the artificially polluted water. We obtain that the defluorination rate reaches 50.37 %, the defluorination energy efficiency is 769.37 mg/kWh, and an energy consumption (EE/O) is 44.68 kWh/m3 after 60 min treatment in 3D gliding arc air plasma. Active radical concentrations of & sdot; O 2- , O3, H2O2, NO2- and NO3- in the gaseous and liquid phases varying with the solution pH and conductivity during the degradation process is noticed, and & sdot; O 2- playing the most important role in PFOA defluorination is conformed. Besides, the discharge characteristics are investigated by high-speed camera in whole discharge cycle, and the radical sorts in gaseous plasma are detected by optical emission spectroscopy (OES) for well understanding the degradation mechanism. With liquid chromatograph mass spectrometer (LC-MS) measurement, the intermediate and final products during PFOA degradation are found, and then the degrading pathways are proposed. Furthermore, the toxicity of the intermediates is simulatively analyzed, which demonstrates that the toxicity and bioaccumulation factors of the intermediates are greatly reduced after plasma treatment. Therefore, we believe that gliding arc plasma may be a promising plasma source for green, fast and efficient wastewater treatment.

Graphene is widely used as an advanced functional carbon material. We report a new high power impulse magnetron sputtering (HiPIMS) process for C:Ni film. After rapid thermal annealing, graphene was directly fabricated on SiO2/Si substrates. The study systematically investigates the factors influencing the graphene layer number and its quality during preparation, including the C2H2 flow rate, deposition time, gas pressure, annealing temperature, annealing time, and heating rate. High-quality few-layer graphene was successfully fabricated under a certain condition: a C2H2 flow rate of 0.6 sccm for 60 s, a working pressure of 0.3 Pa, an annealing time of 10 min and an annealing temperature of 900 degrees & Scy;. The results provide a method for synthesizing graphene directly on the substrate at low temperatures by HiPIMS, offering significant potential for advancing graphene preparation technology and the application of graphene materials.

A four-turn solenoid antenna has been used to produce high-density helicon plasma in an inhomogeneous magnetic field. Different magnetic field needed for the helicon plasma discharge can be realized easily by moving the axial positions of the solenoid antenna. Three different axial positions, e.g., 6 cm, 12 cm, and 18 cm, had been selected to fix the four-turn solenoid antenna; correspondingly, the magnetic field intensities were 7.69 G, 30.77 G, and 123.08 G, respectively. It was found that the blue core phenomenon appeared at around 300 W and an antenna position of 18 cm. The plasma density can be up to 2 × 1019 m−3 with an antenna coupling efficiency of 90% at 600 W in the blue core. The power coupling mechanism has been discussed based on the helicon plasma discharge diagnostics.

Incorporating suitable promoters into nickel-based catalysts for carbon dioxide methanation proves to be a successful strategy for enhancing catalyst structure, optimizing surface properties, mitigating deactivation, and ultimately boosting catalytic performance. This study focuses on the synthesis of Co-modified Ni/CaCO3 catalysts using the solution combustion synthesis method. The catalytic activity of the afforded catalysts has been evaluated for CO2 methanation in a dielectric barrier discharge reactor operating at a gaseous hourly space velocity of 11,320 h(-1) and an H-2:CO2 ratio of 4:1. The catalyst exhibits optimal performance at a Ni:Co ratio of 13:2, achieving a CO2 conversion rate of 57.5% and CH4 selectivity of 92.4%. Characterization techniques such as X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, programmed temperature-raising hydrogen reduction, carbon dioxide desorption, and in situ plasma DRIFTS are employed to evaluate the catalysts. The results indicate that the addition of Co to Ni-based catalysts leads to an increase in moderately basic sites, thereby enhancing the catalytic activity and stability of catalysts for CO2 methanation. Notably, the combination of the plasma and the Ni-Co catalyst offers a novel pathway for CO2 methanation, featuring higher energy efficiency and superior synergistic effects compared to monometallic catalysts.