The CrAlCN composite coatings were deposited using cathodic arc technology, and the effects of acetylene (C2H2) flow rates on the microstructure, mechanical properties, and tribological performance of CrAlCN coatings were investigated. The results reveal that the coating grains are progressively refined, and the crystallographic orientation shifts from (111) and (200) planes to a dominant (200) orientation with increasing C2H2 flow rate from 0 to 60 sccm. The hardness of the coatings first increases and then decreases, and the maximum hardness is achieved at a C2H2 flow rate of 20 sccm. The precipitation of amorphous carbon induces a structural transformation from a single-phase crystalline structure to a nanocrystalline /amorphous composite at a C2H2 flow rate of 60 sccm, thereby leading to the reduction in the coefficient of friction (COF). The wear mechanism of the nc-CrAlCN/a-C composite coatings against Si3N4 counter-balls is characterized by mild adhesive and abrasive wear. The formed lubricating film is prone to being squeezed out of the wear track, resulting in a low COF but a significantly increased wear rate at high C2H2 flow rates. In contrast, the minimum wear rate was observed at a flow rate of 20 sccm, where a continuous carbon-rich lubricating layer is formed on the wear track. Therefore, the optimal C2H2 flow rate significantly optimizes mechanical properties and boosts the tribological performance of the CrAlCN coatings.

With the increasing demand for non-destructive ultra-smooth surface optical components in optical systems, a polishing liquid with asphalt interface modification was proposed for small tool polishing to meet application requirements. Dodecylbenzenesulfonic acid (DBSA) promotes the dispersion of abrasive particles, improves the stability of the polishing liquid, and simultaneously reduces the contact angle. Additionally, DBSA regulates the modification effect of mineral oil (MO) on the asphalt polishing pad through emulsification. This process addresses the issue of abrasive particle accumulation on the polishing pad, reduces the average load of effective abrasive particles at the interface, and promotes material removal primarily through mechanically induced chemical bond breaking. Under a scanning area of 20 × 20 µm2, the surface roughness of quartz glass reaches Ra 0.097 nm, providing what we believe to be a novel approach to achieving an ultra-smooth surface without surface or subsurface destruction.

This study investigates the processing temperature characteristics and etching behavior of fused silica using an atmospheric pressure microwave plasma jet. The temperature distribution within the processing region was measured in real time via infrared thermography. The effects of microwave input power, argon flow rate, and CF4 flow rate on the processing temperature were systematically examined using a single-factor approach. Experimental results reveal a strong positive correlation between the plasma temperature and microwave power. The temperature initially rises and then declines with increasing argon flow, peaking at 3 slm, while it increases and eventually stabilizes with higher CF4 flow. Fixed-point etching demonstrates that the etching rate increases with rising processing temperature. Furthermore, heat accumulation during prolonged dwell time leads to a nonlinear increase in the removal rate. This effect can be effectively mitigated by employing a multi-segment processing strategy, enabling more stable and controllable material removal. The effectiveness of this processing method has also been verified on a fused quartz sub-mirror.

The high-performance fabrication of fused silica optical components faces the core challenge of achieving high efficiency and low damage in removing processing-induced defects while simultaneously improving form accuracy and surface roughness. To address this bottleneck, this paper proposes a novel synergistic processing strategy combining atmospheric pressure microwave plasma (APMP) etching with conformal polishing using a small tool. The processing mechanism is as follows: under optimized conditions, APMP exhibits a high material removal rate, and its low thermal/mechanical stress characteristics enable effective removal of surface and subsurface defects introduced by grinding while correcting form errors. However, the isotropic nature of plasma etching leads to surface roughness degradation. Subsequently, conformal polishing with a small tool selectively smooths microscopic peaks through a "gentle" material removal mechanism without introducing new subsurface damage or scratches, and conforms to the local surface topography, thereby repairing the deteriorated roughness while preserving the form accuracy corrected by the plasma step. The two processes complement each other, balancing high removal efficiency and high surface quality. Using the proposed synergistic process, the form error RMS of a fused silica mirror was reduced from 38.01 nm to 9.03 nm, and the average surface roughness Sa was reduced from 0.811 nm to 0.322 nm. Verification by buffered oxide etch (BOE) confirmed that the final component is free of subsurface damage. The results demonstrate that the synergistic processing method combining APMP etching and conformal polishing with a small tool is a promising approach for ultra-precision surface machining of fused silica glass.

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.

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.

Triboelectric nanogenerator (TENG) is widely used in the fields of sustainable green energy harvesting, self-powered motion parameter and tactile sensing, However, it still fails to meet the requirements under various complex conditions, such as low temperatures, self healing after destruction, punching, long-term placement, soaking in acid or alkali solution, scorch, continuous work. Herein, based on metal coordination, Zr4+ ions are introduced to enhance the first network k-carrageenan (k-CG) for achieving double enhancement in mechanics and electricity of the gel electrode layer, poly (N-hydroxyl acrylamide)/k-CG (PKZ) double network organic conductive gel enhanced by multiple hydrogen bonds and metal coordination bond is designed, and the gel exhibits high tensile strength, high conductivity, fast self-recovery, excellent self-repairing and low-temperature resistance. Based on simple sandpaper templates with different mesh numbers Ecoflex film with rough surfaces is designed for efficient triboelectric contact interface, and TENG with PKZ double network organic conductive gel as electrode layer is constructed, and possesses excellent resistant to multiple complex conditions. With high short-circuit current, open-circuit voltage and output power, the TENG is capable of powering electronic devices, and it can also be sensitive and stable sensing in writing recognition, real-time monitoring of motion parameters involving acceleration, speed and distance. The TENG is stable and reliable for sustainable green energy harvesting, motion parameter and tactile sensing in multiple complex environments. Thus, we provide novel ideas for designing energy harvesting and sensing for future wearable electronics under multiple complex conditions.

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.

The polymer deposition layer (PDL) formed during inductively coupled plasma (ICP) processing significantly limits the figuring accuracy and surface quality of fused silica optics. This study investigates the formation mechanism, composition, and evolution of the PDL under varying dwell times and proposes an innovative dwell time gradient strategy to suppress roughness deterioration. A significant disparity in hardness and elastic modulus between the deposition layer and the substrate is revealed, explaining its preferential removal and protective buffering effect in computer-controlled optical surfacing (CCOS). A hybrid ICP-CCOS polishing process was developed for processing a ϕ100 mm fused silica mirror. The results show that within 33 min, the surface graphic error RMS was significantly reduced from 58.006 nm to 12.111 nm, and within 90 min, the surface roughness was ultra-precisely reduced from Ra 1.719 nm to Ra 0.151 nm. The average processing efficiency was approximately 0.63 cm2/min. Critically, a damage-free, ultra-smooth surface without subsurface damage (SSD) was successfully achieved. This hybrid process enables the simultaneous optimization of figure accuracy and roughness, eliminating the need for iterative figuring cycles. It provides a novel theoretical framework for high-precision figuring and post-ICP polymer removal, advancing the efficient fabrication of high-performance optics.

Cr/CrN/Cr and CrN/Cr/CrN multilayer coatings, as well as CrN monolayer coating, were successfully prepared on 316L stainless steel by cathodic arc technique, and their corrosion resistance and conductivity were systematically investigated in simulated proton exchange membrane fuel cells (PEMFCs) environment. As a result, CrN/Cr/CrN and CrN coatings perform better corrosion resistance and durability than Cr/CrN/Cr coating. This is attributed to the superior chemical inertness and high compactness of CrN, which can block the penetration of the electrode effectively. All the coatings perform p-type semiconductors owing to the chromium oxides, and CrN/Cr/CrN coating shows the lowest acceptor density (NA) owing to limited carrier transport caused by the interface effects between layers. Moreover, CrN/Cr/CrN coating has the lowest interfacial contact resistance (ICR) after PSP tests, which is attributed to the good corrosion resistance of the outer CrN layer and the inner Cr layer with high electron mobility. This finding proves the potential application of Cr/CrN multilayer coating in PEMFCs.

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.

Transition metal dichalcogenides like MoS2 have been considered as crucial channel materials beyond silicon to continuously advance transistor scaling down owing to their two-dimensional structure and exceptional electrical properties. However, the undesirable interface morphology and vibrational phonon frequency mismatch between MoS2 and the dielectric layer induce low thermal boundary conductance, resulting in overheating issues and impeding electrical performance improvement in the MoS2 field-effect transistors. Here, we employed hybrid high-k dielectric layers of Al2O3/HfO2 to simultaneously reduce the interfacial thermal resistance and improve device electrical performance. The enhanced contact, greater vibrational phonon overlapping region, and stronger interfacial bonding force between the top Al2O3 layer and MoS2 promote the heat removal efficiency across the interface to the substrate. Under the same input power density, the temperature profile of the MoS2 transistor on the Al2O3/HfO2 has been largely reduced compared to that of the device on HfO2, with a maximum reduction of 49.5 degrees C. In addition, the field-effect mobility and current of MoS2 devices on the Al2O3/HfO2 high-k dielectric layers have been significantly improved, attributed to the depressed electron scattering and trap states at the interface. The design of the hybrid high-k dielectric layers provides an efficient solution to simultaneously improve the thermal and electrical performance of the two-dimensional devices.

Nonthermal plasma (NTP) provides a potential and sustainable route for the synthesis of ammonia. In this work, a Co-Ni/MOF-74 catalyst was developed to synthesize ammonia from N-2 and H-2 in a dielectric barrier discharge (DBD) plasma at low temperature and atmospheric pressure. Co-Ni/MOF-74 showed the highest ammonia synthesis rate up to 2608.70 mu mol g(-1) h(-1) at 200 degrees C, with V(N-2):V(H-2) ratio of 1:1 and specific energy input of 33.27 kJ L-1. The catalytic activity was increased by 19.57% for Co-Ni/MCM-41 and 375% for Co-Ni/Al2O3, respectively. It was observed that the average electric field (E) and power efficiency were enhanced while adding Co-Ni/MOF-74 to the reaction system.

The characteristics of the blue core phenomenon observed in a divergent magnetic field helicon plasma are investigated using two different helical antennas, namely right-handed and lefthanded helical antennas. The mode transition, discharge image, spatial profiles of plasma density and electron temperature are diagnosed using a Langmuir probe, a Nikon D90 camera,an intensified charge-coupled device camera and an optical emission spectrometer, respectively.The results demonstrated that the blue core phenomenon appeared in the upstream region of the discharge tube at a fixed magnetic field under both helical antennas. However, it is more likely to appear in a right-handed helical antenna, in which the plasma density and ionization rate of the helicon plasma are higher. The spatial profiles of the plasma density and electron temperature are also different in both axial and radial directions for these two kinds of helical antenna. The wavelength calculated based on the dispersion relation of the bounded whistler wave is consistent with the order of magnitude of plasma length. It is proved that the helicon plasma is part of the wave mode discharge mechanism.

The prevention and treatment of organic pollutants in wastewater have attracted extensive attention because they threaten ecological balance and human health. Traditional wastewater treatment technologies, such as physical, chemical, biological methods, etc., are still limiting and challenging due to some factors, such as high energy consumption, chemical agents, low efficiency, and secondary pollution. At present, gliding arc plasma, based on equilibrium/non-equilibrium in plasma temperature, demonstrates itself to be one of the most promising technologies for the degradation of refractory organics with its fast degradation rates, no secondary contamination, high efficiency, and so on. The theoretical mechanisms and typical applications of gliding arc plasma degradation of wastewater are introduced in detail in this paper. The physical and chemical characteristics of gliding arc plasma and the role of the reactive species in the plasma are reviewed.

Advancements in astronomical telescopes and cutting-edge technologies, including deep ultraviolet (DUV) and extreme ultraviolet (EUV) lithography, have escalated demands and imposed stringent surface quality requirements on optical system components. Achieving near-ideal optical components requires ultra-smooth surfaces with sub-nanometer roughness, no sub-surface damage, minimal surface defects, low residual stresses, and intact lattice integrity. This necessity has driven the rapid development and diversification of ultra-smooth surface fabrication technologies. This paper summarizes recent advances in ultra-smooth surface processing technologies, categorized by their material removal mechanisms. A subsequent comparative analysis evaluates the roughness and polishing characteristics of ultra-smooth surfaces processed on various materials, including fused silica, monocrystalline silicon, silicon carbide, and sapphire. To maximize each process’s advantages and achieve higher-quality surfaces, the paper discusses tailored processing methods and iterations for different materials. Finally, the paper anticipates future development trends in response to current challenges in ultra-smooth surface processing technology, providing a systematic reference for the study of the production of large-sized freeform surfaces.

Oxygen (O-2) helicon plasmas in multiple wave modes were excited by a right-helical antenna with an upper metal endplate at low pressure. Mode transitions were observed at increasing input power or magnetic field, characterized by obvious jumps of plasma parameters. Blue Core appears at high magnetic fields (similar to 700 G) and input powers (similar to 1700 W), with a large radial gradient of plasma density, ion line intensity, and electron temperature. Emission spectra demonstrate that the blue lights originate from O II lines. We found that the intensity ratio of O II to O I of Blue Core in O-2 is lower by one order than that in N-2 or Ar despite their similar ionization rates and plasma densities in the Blue Core area. A high-temperature B-dot probe together with a waveform fitting procedure was used to present the measured oscillating waveforms of m = +1 helicon waves, showing distinct wave structures of different eigenmodes. Cavity mode resonance is suggested to be responsible for the formation of standing waves of discrete eigenmodes. A pressure balance model was developed to estimate the species densities around the central area in different modes, showing massive dissociation of O-2 molecules and high density of O atoms locally, so that O-2 helicon plasma behaves as a species feature of monatomic gas discharge. The obviously low intensity of the O II lines compared to the O I lines of Blue Core in O-2 is related to the quite high excitation threshold of O+ ions (similar to 30 eV) although electron density and temperature are relatively high. The combined effects of dispersed reaction energy distribution, massive molecule dissociation and negative ion creation are considered to be the main causes for the requirement of much higher RF power and magnetic field for Blue Core formation in O-2 helicon plasma than that in Ar. The calculated radial profiles of power deposition and the captured plasma morphology confirm that the dominant central electron heating is the essential reason for the large radial gradients of plasma density and electron temperature which contribute to the serious neutral depletion and Blue Core formation.

Chirality, a ubiquitous phenomenon in nature, profoundly influences material properties. The precise synthesis of chiral compounds and enantiomer recognition techniques hold promise as pivotal advancements in the realms of medicine, informatics, and materials science, yet remain a formidable challenge. In this paper, we prepared a monochiral self-forming microporous polymers ((R)-HSBI-Is) R )-HSBI-Is) through direct-synthesis method, and applied it for chiral recognition of phenylalanine. First, commencing with bisphenol A, racematic 3,3,3',3'-tetramethyl-1,1'-spirodine-7,7'-diol (6,6'-TMSOL) was synthesized, and form transitional complex derivates through adding chiral reagents (L-menthyl L-menthyl chloroformate). After three times recrystallization under- 18 degree celsius , the diastereoisomers of the complex derivates were successfully separated due to their different solubility. After hydrolysis reaction, the auxiliary groups were removed and chiral monomer was synthesized. This study achieved the artful synthesis of pure (R)-3,3,3',3'-tetramethyl-1,1'-spirodine-7,7'-diol R )-3,3,3',3'-tetramethyl-1,1'-spirodine-7,7'-diol ((R)-6,6'-TMSOL). R )-6,6'-TMSOL). Subsequently, chiral polymer of intrinsic microporosity ((R)-HSBI-Is) R )-HSBI-Is) were crafted through Friedel-Crafts reaction with isatin molecules. And we delved the mechanism of synthesizing chiral polymers. These polymers were comprehensively evaluated using techniques such as nuclear magnetic resonance, infrared spectroscopy, UV spectroscopy, specific surface area and pore size analysis, and thermogravimetric analysis. Our findings reveal that the polymer boasts a high specific surface area and robust fluorescence. It also shows a great performance in thermal stability. The fluorescence experiments on chiral molecules (phenylalanine, tryptophan, 1,1'-binaphthyl-2,2'-diol (BINOL), 1,1'-spirobiindane (SPINOL) and 1-phenylethanol) were carried out to testify the recognition performance of chiral polymer. The results proved that the polymer exhibits a remarkable selective fluorescence enhancement towards L-phenylalanine. Specifically, the L- and D-configuration selectivity achieved is 34.9, positioning it as an exceptional chiral recognition agent for L-phenylalanine.

Ammonia is one of the most important chemical raw materials in both manufacture and life of human. Traditionally Haber-Bosch method for ammonia synthesis involves high temperature and high pressure conditions, leading to significant energy consumption and environmental pollution. Non-thermal plasma (NTP) is a promising alternative approach to ammonia synthesis at low temperature and atmospheric pressure. In this study, the synergistic effect of nanosecond pulsed dielectric barrier discharge (np-DBD) and Ni-MOF-74 catalyst was investigated in ammonia synthesis by utilizing nitrogen and hydrogen as feedstock. The results demonstrated that the plasma catalytic-synthesis process parameters play a crucial role in the synthesis process of ammonia. The highest ammonia synthesis rate of 5145.16 mu molg-1h-1 with an energy efficiency of 1.27 gkWh-1 was observed in the presence of the Ni-MOF-74 catalyst, which was 3.7 times higher than that without Ni-MOF-74 catalyst. The synergistic effect of Ni-MOF-74 catalyst and nanosecond pulsed plasma was explored by in-situ plasma discharge diagnostics.