Plasma-assisted Ru/Zr-MOF catalyst for hydrogenation of CO2 to methane

As an important type of metal-organic framework(MOF),Zr-MOF shows excellent CO2 adsorption performance.In this work,a Zr-MOF was synthesized by a solvothennal method and adopted to support Ru through simple incipient-wetness impreg nation.Then the Ru/Zr-MOF was applied for CO2 hydrogenation(Vh2:VCO2=4:1)with the assistance of dielectric banner dischai'ge(DBD)plasma.The hydrogenation of Cd2 results showed that methane was produced selectively under the synergistic effect between plasma and the Ru/Zr-MOF catalyst,and the selectivity and yield of methane reached 94.6%and 39.1%,respectively.The XRD and SEM analyses indicate that the basic crystalline phase structure and morphology of the Zr-MOF and Ru/Zr-MOF remained the same after DBD plasma treatment,suggesting that the catalysts are stable in plasma.The guest molecules in the pores of the Zr-MOF are removed and the Ru"ions are reduced to metallic Ru()in the reduction atmosphere according to the BET and XPS results,which are responsible for the high performance of plasma with the Ru/Zr-MOF catalyst.In situ optical emission spectra of pure plasma,plasma with Zr-MOF,and plasma with Ru/Zr-MOF were measured,and the active species of C,H and CH for CO2 hydrogenation were detected.The plasma-assisted Ru/Zr-MOF exhibited high catalytic activity and stability in CO2 hydrogenation to methane,and it has great guiding significance for CO2 hydrogenation by using plasma and MOF materials.

Partially crystallized Pd nanoparticles decorated TiO_2 prepared by atmospheric-pressure cold plasma and its enhanced photocatalytic performance

TiO2 decorated with partially crystallized Pd nanoparticles （Pd/TiO2-P） was successfully prepared by atmospheric-pressure dielectric barrier discharge cold plasma. The XRD and XPS analyses proved that Pd ions were reduced to partially crystallized metallic Pd nanoparticles in Pd/TiO2-P. The XPS spectra also indicated that an enhanced metal-support interaction was formed due to the existence of partially crystallized Pd nanoparticles with lower coordination number in Pd/TiO2-P. Photocatalytic activity of Pd/TiO2-P was much higher than that of TiO2 samples decorated with well crystallized Pd nanoparticles.

Methane conversion under cold plasma over Pd-containing ionic liquids immobilized on γ-Al_2O_3

Pd-containing ionic liquid （IL） 1-hexyl-3-methylimidazolium tetrafluoroborate （C6MIMBF4） immobilized on γ-Al2O3 （Pd-IL/γ-Al2O3） was prepared and characterized by Fourier transform infrared spectroscopy （FTIR）, scanning electron microscopy （SEM） and Brunauer-Emmett- Teller （BET） analysis. The influences of C6MIMBF4 loading and Pd on methane conversion to C2 hydrocarbons under cold plasma were investigated. FTIR and SEM analyses indicated that C6MIMBF4 had been successfully immobilized on γ-Al2O3 and the C6MIMBF4 showed excellent stability under cold plasma. The results of BET and methane conversion showed that with the increase in immobilization amount of C6MIMBF4 onto γ-Al2O3, the specific surface area and pore volume of IL/γ-Al2O3 decreased, while the selectivity and yield of C2 hydrocarbons increased. The selectivity of C2 hydrocarbons was 94.6% when the loading of C6MIMBF4 was 40%, and the percentage of C2H4 in C2 hydrocarbons was as high as 64% when using Pd-IL/γ-Al2O3 as a catalyst with no conventional thermal reduction treatment. Optical emission spectra （OES） from the cold plasma reactor during methane conversion were also studied. The results indicated that the intensity of the C2, CH, H, and C active species from methane and hydrogen decomposition increased when IL/γ-Al2O3 or Pd-IL/γ-Al2O3 was introduced into the plasma system. Based on the analyses of the gas product and OES spectra, it can be concluded that the surface catalyzed reactions between plasma and ionic liquid were very important for the reduction of Pd2＋ and the formation of C2H4.

Preparation of N-doped graphite oxide for supercapacitors by NH_(3) cold plasma

In this work,N-doped graphite oxide(GO-P)was prepared by cold plasma treatment of GO using a mixture of NH_(3) and Ar as the working gas.When the ratios of NH_(3):Ar were 1:2,1:3,and 1:4,the specific capacitances of the GO-P(NH_(3):Ar=1:2),GO-P(NH_(3):Ar=1:3),and GO-P(NH_(3):Ar=1:4)were 124.5,187.7,and 134.6 F·g^(-1),respectively,which were 4.7,7.1,and 5.1 times that of GO at the current density of 1 A·g^(-1).The capacitance retention of the GO-P(NH_(3):Ar=1:3)was 80%when it was cycled 1000 times.The characterization results showed that the NH_(3)cold plasma could effectively produce N-doped GO and generate more active defects.The N/C ratio and the contents of pyridinic nitrogen and graphitic nitrogen of the GO-P(NH_(3):Ar=1:3)were the highest.These were conducive to providing pseudocapacitance and reducing the internal resistance of the electrode.In addition,the ID/IGof the GO-P(NH_(3):Ar=1:3)(1.088)was also the highest,indicating the highest number of defects.The results of discharge parameters measurement and in situ optical emission spectroscopy diagnosis of NH_(3) plasma showed that the discharge is the strongest when the ratio of NH_(3):Ar was 1:3,thereby the generated nitrogen active species can effectively promote N-doping.The N-doping and abundant defects were the keys to the excellent electrochemical performance of the GO-P(NH_(3):Ar=1:3).NH_(3) cold plasma is a simple and rapid method to prepare N-doped GO and regulate the N-doping to prepare high-performance supercapacitors.

Statistical study on great geomagnetic storms during solar cycle 23

Characteristics of great geomagnetic storms during solar cycle 23 were statistically investigated. Firstly, we focused on the uniqueness of solar cycle 23 by analyzing both the great storm number and sunspot number from 1957 to 2008. It was found that the relationship between the sunspot number and great storm number weakened as the activity of the storms strengthened. There was no obvious relationship between the annual sunspot number and great storm number with Dst≤-300 nT. Secondly, we studied the relationship between the peak Dst and peak Bz in detail. It was found that the condition Bz〈-10 nT is not necessary for storms with Dst≤-100 nT, but seems necessary for storms with Dst≤-150 nT. The duration for Bz≤-10 nT has no direct relationship with the giant storm. The correlation coefficient between the Dst peak and Bz peak for the 89 storms studied is 0.81. After removing the effect of solar wind dynamic pressure on the Dst peak, we obtained a better correlation coefficient of 0.86. We also found the difference between the Dst peak and the corrected Dst peak was proportional to the Dst peak.

In-situ reduction of silver by surface DBD plasma:a novel method for preparing highly effective electromagnetic interference shielding Ag/PET

Electromagnetic interference(EMI)shielding composites with good flexibility and weatherability properties have attracted increased attention.In this study,we combined the surface modification method of sub-atmospheric pressure glow discharge plasma with in situ atmospheric pressure surface dielectric barrier discharge plasma(APSDBD)reduction to prepare polyethylene terephthalate supported silver(Ag/PET).Due to the prominent surface modification of PET film,mild plasma reduction,and effective control of the silver morphology by polyvinylpyrrolidone(PVP),a 3.32μm thick silver film with ultralow sliver loading(0.022 wt%)exhibited an EMI shielding efficiency(SE)of 39.45 d B at 0.01 GHz and 31.56 d B at 1.0 GHz(>30 d B in the range of 0.01–1.0 GHz).The SEM results and EMI shielding analysis indicated that the high performance originated from the synergistic effect of the formation of silver nanoparticles(Ag NPs)with preferentially oriented cell-like surface morphologies and layer-by-layer-like superimposed microstructures inside,which demonstrated strong microwave reflection properties.Fourier transform infrared spectrometer and x-ray diffractometer showed that the surface structures of the heat-sensitive substrate materials were not destroyed by plasma.Additionally,APSDBD technology for preparing Ag/PET had no special requirements on the thickness,dielectric constant,and conductivity of the substrate,which provides an effective strategy for manufacturing metal or alloy films on surfaces of heat-sensitive materials at a relatively low cost.

Plasma-assisted Co/Zr-metal organic framework catalysis of CO_(2)hydrogenation:influence of Co precursors

In this study,Co/Zr-metal organic framework(MOF)precursors were obtained by a roomtemperature liquid-phase precipitation method and the equivalent-volume impregnation method,respectively,using a Zr-MOF as the support,and Co/Zr-MOF-M and Co/Zr-MOF-N catalysts were prepared after calcination in a hydrogen-argon mixture gases(VAr:V_(H_(2))=9:1)at 350℃for 2 h.The catalytic activities of the prepared samples for CO_(2)methanation under atmosphericpressure cold plasma were studied.The results showed that Co/Zr-MOF-M had a good synergistic effect with cold plasma.At a discharge power of 13.0 W,V_(H_(2)):VCO_(2)=4:1 and a gas flow rate of 30 ml·min^(-1),the CO_(2)conversion was 58.9%and the CH4 selectivity reached 94.7%,which was higher than for Co/Zr-MOF-N under plasma(CO_(2)conversion 24.8%,CH4 selectivity 9.8%).X-ray diffraction,scanning electron microscopy,transmission electron microscopy,N_(2)adsorption and desorption(Brunauer-Emmett-Teller)and x-ray photoelectron spectroscopy analysis results showed that Co/Zr-MOF-M and Co/Zr-MOF-N retained a good Zr-MOF framework structure,and the Co oxide was uniformly dispersed on the surface of the Zr-MOF.Compared with Co/Zr-MOF-N,the Co/Zr-MOF-M catalyst has a larger specific surface area and higher Co^(2+)/Cototaland Co/Zr ratios.Additionally,the Co oxide in Co/ZrMOF-M is distributed on the surface of the Zr-MOF in the form of porous particles,which may be the main reason why the catalytic activity of Co/Zr-MOF-M is higher than that of Co/ZrMOF-N.

Construction of metal-organic frameworks with unsaturated Cu sites for efficient and fast reduction of nitroaromatics:A combined experimental and theoretical study

Metal-organic frameworks(MOFs)functionalized with open metal sites(OMSs)have received widespread attention in various applications due to their fascinating electronic properties and unique interactions with guest molecules.However,rational tailoring of the coordination environment of metal nodes dur-ing the synthesis of MOFs remains a great challenge due to their tendency of saturated coordination with linkers.Herein,we reported the construction of three new MOFs featuring unsaturated Cu(Ⅱ)sites,namely[Cu(HCOO)(pzta)]_(n)(HL-1),{[Cu(PTA)0.5(pzta)(H_(2)O)]·2H_(2)O}_(n)(HL-2)and[Cu(NA)0.5(pzta)]_(n)(HL-3)(Hpzta=3-pyrazinyl-1,2,4-triazole;PTA=terephthalic acid;NA=1,4-naphthalene dicarboxylic acid),based on the mixed-linker strategy via specific selection of versatile Hpzta ligand and carboxylate ligands.Re-markably,the obtained MOFs exhibited excellent activity and good recyclability for the catalytic reduction of nitroaromatics under mild conditions(25℃and 1 atm).In particular,the complete conversion of 4-nitrophenol(4-NP)took only 30 s on HL-2,reaching a record-high TOF value compared with previously reported metal catalysts.The combined experimental and theoretical studies on HL-2 revealed that the open Cu site with positive-charged nature could improve the adsorption and subsequent electron trans-port between the substrates,and was responsible for the outstanding performance.This work shined lights on the further enhancement of performance for MOFs through rational OMSs construction.

Mitochondrial aberrations in systemic lupus erythematosus pathogenesis:Insights and therapeutic implications

Systemic lupus erythematosus(SLE),a chronic autoimmune disease,is marked by impaired immune tolerance and heightened activity in both innate and adaptive immune systems.Hallmarks of SLE include elevated type I interferons and autoantibody production,though the exact causes of SLE remain elusive despite advances in research techniques.Crucial to SLE research is understanding its pathogenesis and developing effective diagnostic and therapeutic methods.Recent studies have highlighted a significant link between mitochondrial abnormalities and SLE's development and progression.Mitochondrial dysfunction plays a key role in SLE pathogenesis through various mechanisms such as mitochondrial DNA mutations,oxidative stress,immune metabolic reprogramming,and cellular death.These factors collectively contribute to the loss of self-tolerance,increased autoantibody production,and impaired clearance of immune complexes,leading to their deposition.This triggers sustained inflammatory responses and damages multiple organs.This review focuses on the diagnostic and therapeutic approaches related to mitochondrial abnormalities in SLE.Targeting mitochondrial pathways presents a promising strategy for treating SLE,potentially improving prognosis and quality of life for those affected.Future research should further investigate the role of mitochondria in the onset and progression of SLE,providing new avenues for understanding and managing this complex disease.

Carbon Nanofibers Encapsulated CoNiFe Bifunctional Electrocatalysts for Durable Zn-Air Batteries at Room and -40℃ Ultralow Temperatures

Reasonably designing composition and nanostructure to enhance the stability of bifunctional catalysts is highly desired for rechargeable Zn-air batteries(ZABs).Here,porous carbon nanofibers(CNFs)encapsulated CoNiFe alloy nanoparticles(NPs)(CoNiFe/CNFs)were synthesized controllably by in-situ growth and cation etching.Electrochemical tests indicated that CoNiFe/CNFs exhibited excellent bifunctional performances in both oxygen evolution reaction(OER)and oxygen reduction reaction(ORR).Using CoNiFe/CNFs as bifunctional catalysts,the assembled ZABs presented ultralong durability up to 1050 and 660 h at 5 and 25 mA cm^(-2),respectively.The assembled flexible solid-state ZABs-based polyacrylamide(PAM)hydrogel exhibited a power density of 62.9 mW cm^(-2) and 66 h durability at 2 mA cm^(-2) under ultralow temperature of -40℃.The excellent performance of CoNiFe/CNFs was ascribed to the encapsulation of CNFs by the alloy NPs and the synergy of multi-metals in the alloy NPs,because the encapsulation could suppress alloy spillage and agglomeration and protect the catalytic sites from electrolyte deterioration,thereby boosting the durability of the resulting ZABs.

Construction of novel cluster-based MOF as multifunctional platform for CO_(2) catalytic transformation and dye selective adsorption

Synthetic conditions and ligands are the key structural defining factors of metal-organic frameworks(MOFs).Therefore,reasonable optimization of these aspects is considered to be an effective means for designing materials with novel structures and target functions.Herein,two novel Co(Ⅱ)-based MOFs,namely[Co(HL)(dibp)]_(n)(HL-8) and{[Co_(2)(L)(OH)(dibp)]·DMA}_n(HL-9)(H_(3)L=2',6'-dimethyl-[1,1'-biphenyl]-3,4',5-tricarboxylic acid;dibp=4,4'-di(1H-imidazol-1-yl)-1,1-biphenyl]),have been hydrothermally synthesized and structurally characterized.HL-8 crystallizes in the orthorhombic system (Pna2_(1)) with a grid layer structure,while HL-9 crystallizes in the monoclinic P2_(1)/n space group assembled through Co_(4)(OH)_(2)clusters with organic ligands.Remarkably,benefiting from the finite cage-like structure,HL-9 exhibited enhanced performance in carbon dioxide(CO_(2)) adsorption/catalytic transformation and excellent size selectivity during dye molecular adsorption process.

Self-powered nanofiber-based screen-print triboelectric sensors for respiratory monitoring

Scientific and commercial advances have set high requirements for wearable electronics. However, the power supply, breathability, and mass production of wearable electronics still have many challenges that need to be overcome. In this study, a self-powered nanofiber-based triboelectric sensor （SNTS） was fabricated by batch-scale fabrication technologies using electrospinning and screen-printing for health monitoring via respiratory monitoring. Typically, an arch structural SNTS is assembled by a nanofiber membrane and a Ag nanoparticle electrode. The pile of nanofibers and the conductive network of Ag nanoparticles ensure a gas channel across the whole device. The gas permeability of the SNTS was as high as 6.16 mm/s, which has overwhelming advantages when compared with commonly used wearable devices composed of air-tight cast films. Due to the softness of the nanofiber membrane, the SNTS showed excellent electronic output performance irrespective of whether it was bent, twisted, or folded. The superior properties, such as breathability, skin-friendliness, self-power, and batch fabrication of SNTS offer huge potential for their application in healthcare monitoring and multifunctional intelligent systems.

A transgene-free method for rapid and efficient generation of precisely edited pigs without monoclonal selection

Gene-edited pigs for agricultural and biomedical applications are typically generated using somatic cell nuclear transfer(SCNT).However, SCNT requires the use of monoclonal cells as donors, and the time-consuming and laborious monoclonal selection process limits the production of large populations of gene-edited animals. Here, we developed a rapid and efficient method named RE-DSRNP(reporter RNA enriched dual-sg RNA/CRISPR-Cas9 ribonucleoproteins) for generating gene-edited donor cells. RE-DSRNP takes advantage of the precise and efficient editing features of dual-sg RNA and the high editing efficiency, low off-target effects, transgene-free nature, and low cytotoxic characteristics of reporter RNA enriched RNPs(CRISPR-Cas9ribonucleoproteins), thus eliminating the need for the selection of monoclonal cells and thereby greatly reducing the generation time of donor cells from 3–4 weeks to 1 week, while also reducing the extent of apoptosis and chromosomal aneuploidy of donor cells. We applied RE-DSRNP to produce cloned pigs bearing a deletion edit of the wild-type p53-induced phosphatase 1(WIP1)gene: among 32 weaned cloned pigs, 31(97%) carried WIP1 edits, and 15(47%) were homozygous for the designed fragment deletion, and no off-target event was detected. The WIP1 knockout(KO) pigs exhibited male reproductive disorders, illustrating the utility of RE-DSRNP for rapidly generating precisely edited animals for functional genomics and disease research. REDSRNP's strong editing performance in a large animal and its marked reduction in the required time for producing SCNT donor cells support its application prospects for rapidly generating populations of transgene-free cloned animals.

Two isostructural Ni(Ⅱ)/Co(Ⅱ)-based metal-organic frameworks for selective dye adsorption and catalytic cycloaddition of CO_(2) with epoxides

Two isostructu ral Ni(Ⅱ)/Co(Ⅱ)-based metal-organic frameworks(MOFs),namely {[M_(3)(L)_(2)(bpb)_(3)(H_(2) O)_(4)]·2 DMF·2 H_(2)O}_(n) [M=Ni(HL-5,HL is short for Hui-Ling Liu);M=Co(HL-6);H_(3) L=2',6'-dimethyl-[1,1'-biphenyl]-3,4',5-tricarboxylic acid;bpb=1,4-bis(pyrid-4-yl)benzene],have been hydrothermally synthesized and structu rally characterized.Both HL-5 and HL-6,which have the same three-interpenetrated3 D pillared-layer framework with sqc306 type topology,present good selective methyl orange(MO)adsorption over rhodamine B(RhB).Moreover,the catalytic CO_(2) cycloaddition properties with epoxides of the two MOFs have also been studied at ambient pressure and temperature.