Cold plasma generated by dielectric barrier discharge （DBD） at atmospheric pressure was adopted for preparation of commercial TiO2 Degussa P25 supported Au catalysts （Au/P25- P） with the assistance of the depositi...Cold plasma generated by dielectric barrier discharge （DBD） at atmospheric pressure was adopted for preparation of commercial TiO2 Degussa P25 supported Au catalysts （Au/P25- P） with the assistance of the deposition-precipitation procedure. The influences of the plasma reduction time and calcination on the performance of the Au/P25-P catalysts were investigated. CO oxidation was performed to investigate the catalytic activity of the Au/P25 catalysts. The results show that DBD cold plasma for the fabrication of Au/P25-P catalysts is a fast process, and Au/P25-P （4 min） exhibited the highest CO oxidation activity due to the complete reduction of Au compounds and less consumption of oxygen vacancies. In order to form more oxygen vacancies active species, Au/P25-P was calcined to obtain Au/P25-PC catalysts. Interestingly, Au/P25- PC exhibited the highest activity for CO oxidation among the Au/P25 samples. The results of transmission electron microscopy （TEM） indicated that the smaller size and high distribution of Au nanoparticles are the mean reasons for a high performance of Au/P25-PC. Atmospheric- pressure DBD cold plasma was proved to be of great efficiency in preparing high performance supported Au catalysts.展开更多
Modification of poly(tetrafluoroethylene)(PTFE) films with 2-methacryloyloxyethyl phosphorylcholine(MPC) was performed by low-temperature plasma treatment and grafting polymerization.Surface properties of PTFE were ch...Modification of poly(tetrafluoroethylene)(PTFE) films with 2-methacryloyloxyethyl phosphorylcholine(MPC) was performed by low-temperature plasma treatment and grafting polymerization.Surface properties of PTFE were characterized by attenuated total reflectance Fourier transform infrared(ATR-FTIR) spectra,X-ray photoelectron spectroscopy(XPS) ,and static contact angle.The results show that MPC has been grafted onto PTFE film surface successfully.Contact angle for the modified PTFE films in the water decreased from 108°to 58.25°,while surface energy increased from 17.52 mN/m to 45.47 mN/m.The effects of plasma treatment time,monomer concentration and grafting time on degree of grafting were determined.In the meanwhile,blood compatibility of the PTFE films was studied by checking thrombogenic time of blood plasma.展开更多
Knowledge of plasma composition is very important for various plasma applications and prediction of plasma properties. We use the Saha equation and Debye length equation to calculate the non-local thermodynamic-equili...Knowledge of plasma composition is very important for various plasma applications and prediction of plasma properties. We use the Saha equation and Debye length equation to calculate the non-local thermodynamic-equilibrium plasma composition. It has been shown that the model to 2T with T representing the temperature （electron temperature and heavy-particle temperature） described by Chen and Han [J. Phys. D 32 （1999）1711] can be applied for a mixture of gases, where each atomic species has its own temperature, but the model to 4T is more general because it can be applicable to temperatures distant enough of the heavy particles. This can occur in a plasma composed of big- or macro-molecules. The electron temperature Te varies in the range 8000＊20000K at atmospheric pressure.展开更多
To address the issues of the greenhouse effect and energy dilemma,it is a global hot topic on converting CO_(2)to valuable chemicals and useable fuels.In this review,firstly,we shortly summarize different CO_(2)conver...To address the issues of the greenhouse effect and energy dilemma,it is a global hot topic on converting CO_(2)to valuable chemicals and useable fuels.In this review,firstly,we shortly summarize different CO_(2)conversion methods including thermal catalysis,biocatalysis,electrocatalysis,photocatalysis,and plasma catalysis.Then,a comprehensive overview of the currently explored plasma driven CO_(2)conversion is presented,such as microwave discharge plasma,gliding arc discharge plasma,radiofrequency inductively coupled plasma,and dielectric barrier discharge plasma,with an emphasis on their experimental setups,achievements and limitations.Furthermore,the activation of CO_(2)conversion via the synergistic effect between the plasma and photocatalyst is discussed in detail.Finally,the associated challenges and future development trends for plasma catalytic CO_(2)conversion are briefly concluded.展开更多
Efficient removal of pollutant formaldehyde(HCHO) at room temperature using transition-metal oxides remains a huge challenge to date. Manganese oxide can oxidize formaldehyde, however, how to control the valence state...Efficient removal of pollutant formaldehyde(HCHO) at room temperature using transition-metal oxides remains a huge challenge to date. Manganese oxide can oxidize formaldehyde, however, how to control the valence states of manganese is the key to further improve the removal efficiency. We have successfully prepared porous manganese oxide nanowires(Mn OxNWs) with large surface area and multiple valence states of manganese using simple electrospinning followed by thermal calcination and potassium permanganate solution post-treatment(C/S process). The contents of trivalent and tetravalent manganese increased significantly after C/S process. Moreover, the composition of silver oxide coated silver nanowires(Ag@Ag_(2) O NWs) is realized by assistance with oxygen plasma, which further enhanced high valence manganese. The formaldehyde removal efficiency by Ag@Ag_(2) O–Mn Oxcomposite nanowires can reach 93.7%. The high-efficient catalytic activity is confirmed to attribute to the higher surface area of composite nanowires, the high-valence manganese and the silver oxide for oxidation of formaldehyde.展开更多
Methane conversion in the presence of oxygen under low-temperature radio frequency （RF） plasma was investigated.The experiment results indicated that the following four factors,i.e.,discharge voltage,discharge area,...Methane conversion in the presence of oxygen under low-temperature radio frequency （RF） plasma was investigated.The experiment results indicated that the following four factors,i.e.,discharge voltage,discharge area,O2/CH4 molar ratio and total gas flowrate,affected remarkably the reaction performance.The optimum reaction conditions of methane conversion in the presence of O2 under RF plasma are as follows：discharge voltage 1050 V,discharge area 989.1mm 2,O2/CH4 molar ratio 1/10 and total gas flowrate 200 ml/min.A methane conversion of 91% could be reached under the optimum conditions.Oxygen is good for the breaking of C-H bonds and also acts as a sort of thinner.According to the low-temperature plasma characteristics,the macroscopic kinetics model of methane conversion in the presence of O2 under radio frequency plasma was studied.展开更多
The influence on the effectiveness of sterilization by low-temperature plasma sterilizer CASP-80A was investigated so as to provide a theoretical basis for reducing medical costs and achieving ideal sterilization effe...The influence on the effectiveness of sterilization by low-temperature plasma sterilizer CASP-80A was investigated so as to provide a theoretical basis for reducing medical costs and achieving ideal sterilization effectiveness. To conduct the on-site simulation test, a clinical material sterilization test and a test of the influence of organic substance were conducted, the former by using the representative of Bacillus Stearothermophilus, preparing the bacteria-contaminated carrier through polytetrafluoroethylene （PTFE） simulated hose endoscopes, and the latter by using calf serum as the influence factor of the organic substance. The results show that the CASP-80A low-temperature plasma sterilizer could achieve effective sterilization by either the short-cycle or the long-cycle sterilization method depending on different materials, apparatus, and extent of contamination. The organic substances could influence the effectiveness of sterilization by the low-temperature plasma （H2O2） sterilizer.展开更多
The plasma catalytic degradation of o-xylene in simulated air was improved by loading low amounts of Pt,Pd,or Au onto Co_(3)O_(4).At room temperature,o-xylene conversion and CO_(x)selectivity using a0.1 wt%Pt/Co_(3)O_...The plasma catalytic degradation of o-xylene in simulated air was improved by loading low amounts of Pt,Pd,or Au onto Co_(3)O_(4).At room temperature,o-xylene conversion and CO_(x)selectivity using a0.1 wt%Pt/Co_(3)O_(4)catalyst reached 98.9%and 80%,and the energy efficiency was at the top level in comparison with values in the literature.A stable o-xylene degradation performance could be obtained by online regenerating the heat-insulated reactor with a high energy density.After characterization,it was found that the loading of nanosized Pt not only increased the Co^(3+)/Co^(2+)ratio,where the Co^(3+)benefitted the formation of reactive oxygen species,but also conduced Pt^(0)to oxygen activation,resulting in effective promotion of complete o-xylene oxidation.Operando plasma diffuse reflectance infrared Fourier transform spectroscopy demonstrated the complete o-xylene oxidation and proved that Pt played a key role in the complete oxidation of o-xylene.展开更多
A novel plasma torch nitriding technology was applied for the first time to improve the surface properties of M2 high-speed steel by adjusting different experimental parameters.The nitrogen content,precipitate,microst...A novel plasma torch nitriding technology was applied for the first time to improve the surface properties of M2 high-speed steel by adjusting different experimental parameters.The nitrogen content,precipitate,microstructure,mechanical property,and corrosion resistance of the nitrided layer were comprehensively analyzed using an ONH analyzer,scanning electron microscope(SEM),micro-area X-ray diffractometer,transmission electron microscope(TEM),Vickers microhardness tester,high-temperature wear tester,3D profilometer,tensile testing machine,and electrochemical workstation.The research results show that the novel plasma torch nitriding technology can achieve synergistic strengthening of nitrogen,carbon,and alloying element solid solution,precipitation strengthening,and martensitic structure on the surface of M2 high-speed steel.The nitrogen content on the specimen surface increased up to 0.17%,while the size and area of carbides were reduced by 89%and 86%,respectively,indicating a transformation towards fine nitrogen-rich precipitates.Compared to the original M2 steel,the nitrided specimens exhibited significant improvements in overall performance.The hardness increased from 228 HV_(0.2)to a maximum of 795 HV_(0.2),the wear coefficient decreased from a maximum of 0.8 to 0.49,the tensile strength increased from 753 MPa to a maximum of 934 MPa,and the corrosion current density decreased from 1.2×10^(−5)to a minimum of 1.9×10^(−6)A/cm^(2).展开更多
The production of medical waste(MW)is a growing concern,particularly in light of the increasing annual generation and the exacerbating effects of the COVID-19 pandemic.Traditional techniques such as incineration and l...The production of medical waste(MW)is a growing concern,particularly in light of the increasing annual generation and the exacerbating effects of the COVID-19 pandemic.Traditional techniques such as incineration and landfilling present significant limitations.In this study,a self-designed 50 kW arc plasma reactor was employed to conduct gasification experiments on nitrile-butadiene rubber(NBR)which served as a model of MWand a mixture of NBR/SiO_(2) which served as a model of glass-containing MW,using CO_(2)as the working gas.The CO_(2)thermal plasma gasification process not only ensures the safe and efficient disposal of MW,but also facilitates its effective conversion into H_(2)and CO,achieving a carbon conversion efficiency of 94.52%.The yields of H2 and CO reached 98.52%and 81.83%,respectively,and the specific energy consumption was as low as 3.55 kW·h·kg^(-1).Furthermore,the addition of SiO_(2) was found to inhibit the gasification of NBR and cause damage to the reactor.Therefore,it is recommended that glass waste should be removed prior to the treatment of MW.The CO_(2)thermal plasma gasification technology can not only eliminate environmental and health risks posed by MW,but also convert it into syngas for further utilization.This provides a promising approach to the harmless and resource disposal of MW,while also contributing to the comprehensive utilization of greenhouse gases.展开更多
We present the performance of a post-plasma carbon bed for improving plasma-based CO_(2)conversion,studying the effect of bed length and additional thermal bed insulation.The experiments were conducted using an atmosp...We present the performance of a post-plasma carbon bed for improving plasma-based CO_(2)conversion,studying the effect of bed length and additional thermal bed insulation.The experiments were conducted using an atmospheric pressure gliding arc plasmatron in both high and low specific energy input(SEI)regimes.Each bed was equipped with a silo to enable continuous carbon feeding and operation for an order of 1 h,thus overcoming previous limitations in literature.Importantly,we derive an improved energy efficiency(EE)calculation with an accurate and unambiguous consideration of the key reaction contributions of both plasma and carbon bed.This derivation serves to highlight the inconsistencies that arise in determining EE in such a complex chemical system.We therefore advise and advocate for the use of energy cost(EC)as the key reported energy metric in systems using post-plasma carbon beds.The optimum conversion and energy metrics were obtained with the longest bed,reaching a conversion of 41%,an EE of 51%and an EC of 0.41 MJ/mol at high SEI.The design of the insulated bed and silo allow for previously unreported preheating of the carbon,which reduces oscillations observed in the conversion profiles of the short and long beds.Preheating of the external silo for the long bed also yields a near-complete removal of oscillations.Finally,when comparing our performance with results from literature for postplasma carbon beds,our system clearly improves upon the state-of-the-art,both in absolute values of conversion and energy metrics at the same SEI,as well as by sustaining this improvement for extended periods of time.展开更多
Graphene has enormous potential to capture CO_(2)due to its unique properties and cost-effectiveness.However,graphene-based adsorbents have drawbacks of lower CO_(2)adsorption capacity and poor selectivity.This work d...Graphene has enormous potential to capture CO_(2)due to its unique properties and cost-effectiveness.However,graphene-based adsorbents have drawbacks of lower CO_(2)adsorption capacity and poor selectivity.This work demonstrates a one-step rapid and sustainable N_(2)/H_(2)plasma treatment process to prepare graphene-based sorbent material with enhanced CO_(2)adsorption performance.Plasma treatment directly enriches amine species,increases surface area,and improves textural properties.The CO_(2)adsorption capacity increases from 1.6 to 3.3 mmol/g for capturing flue gas,and from 0.14 to 1.3 mmol/g for direct air capture (DAC).Importantly,the electrothermal property of the plasma-modified aerogels has been significantly improved,resulting in faster heating rates and significantly reducing energy consumption compared to conventional external heating for regeneration of sorbents.Modified aerogels display improved selectivity of 42 and 87 after plasma modification for 5 and 10 min,respectively.The plasma-treated aerogels display minimal loss between 17%and 19% in capacity after 40 adsorption/desorption cycles,rendering excellent stability.The N_(2)/H_(2)plasma treatment of adsorbent materials would lower energy expenses and prevent negative effects on the global economy caused by climate change.展开更多
Molybdenum disulfide(MoS_(2))is identified as one of the most prospective anode materials for sodium ion batteries due to the special layer structure,high working potential and high theoretical capacity.Herein,N-doped...Molybdenum disulfide(MoS_(2))is identified as one of the most prospective anode materials for sodium ion batteries due to the special layer structure,high working potential and high theoretical capacity.Herein,N-doped MoS_(2)nanosheets vertically grown on Ti_(3)C_(2)layers named as N-MoS_(2)-Ti_(3)C_(2)composite has been synthesized by N plasma treatment on MoS_(2)-Ti_(3)C_(2)composite at room temperature.In sodium ion batteries,the N-MoS_(2)-Ti_(3)C_(2)electrode exhibited the initial capacity of 294.2 mAh·g^(−1)at 1 A·g^(−1),and maintained a stable specific capacity of 209.3 mAh·g^(−1)after 500 cycles,better than that of MoS_(2)-Ti_(3)C_(2)(79.0 mAh·g^(−1))and MoS_(2)(30.8 mAh·g^(−1)).The greatly enhanced high rate cycle performance for N-MoS_(2)-Ti_(3)C_(2)can be attributed to the N doping in MoS_(2)and Ti_(3)C_(2).展开更多
In this study,non-thermal plasma(NTP)was employed to modify the Cu/TiO_(2)adsorbent to efficiently purify H_(2)S in low-temperature and micro-oxygen environments.The effects of Cu loading amounts and atmospheres of NT...In this study,non-thermal plasma(NTP)was employed to modify the Cu/TiO_(2)adsorbent to efficiently purify H_(2)S in low-temperature and micro-oxygen environments.The effects of Cu loading amounts and atmospheres of NTP treatment on the adsorption-oxidation performance of the adsorbents were investigated.The NTP modification successfully boosted the H_(2)S removal capacity to varying degrees,and the optimized adsorbent treated by air plasma(Cu/TiO_(2)-Air)attained the best H_(2)S breakthrough capacity of 113.29 mg H_(2)S/gadsorbent,which was almost 5 times higher than that of the adsorbent without NTP modification.Further studies demonstrated that the superior performance of Cu/TiO_(2)-Air was attributed to increased mesoporous volume,more exposure of active sites(CuO)and functional groups(amino groups and hydroxyl groups),enhanced Ti-O-Cu interaction,and the favorable ratio of active oxygen species.Additionally,the X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS)results indicated the main reason for the deactivationwas the consumption of the active components(CuO)and the agglomeration of reaction products(CuS and SO_(4)^(2−))occupying the active sites on the surface and the inner pores of the adsorbents.展开更多
Ti_(2)AlC/TiAl composites with a network structure were successfully prepared with carbon nanotubes and Ti-45Al-8Nb pre-alloyed powder using spark plasma sintering.The effects of sintering temperature(1200-1350℃)on t...Ti_(2)AlC/TiAl composites with a network structure were successfully prepared with carbon nanotubes and Ti-45Al-8Nb pre-alloyed powder using spark plasma sintering.The effects of sintering temperature(1200-1350℃)on the microstructural evolution and mechanical properties were systematically investigated.The microstructure of Ti_(2)AlC/TiAl composites exhibits duplex,near-lamellar,and fully lamellar structures,as the sintering temperature increases from 1200 to 1350℃.The network structured Ti_(2)AlC phase can refine the microstructure and the phase becomes discontinuous at high sintering temperatures.Notably,composites sintered at 1300℃ exhibit excellent mechanical properties,with the highest compressive strength(1921 MPa)and fracture strain(26%)at room temperature.Moreover,the ultimate tensile strength and fracture strain reach 537 MPa and 3.1%at 900℃,and 485 MPa and 3.3%at 950℃,respectively.The enhancement of the mechanical properties is attributed primarily to the load bearing,particle pull-out,and inhibition of crack propagation induced by Ti_(2)AlC particles.展开更多
A modified spark plasma sintering（SPS） technique was developed for the fabrication of Bi2Sr2CaCu2Ox（Bi-2212）superconducting bulks with better intergrain connections. The influences of the modified SPS process on t...A modified spark plasma sintering（SPS） technique was developed for the fabrication of Bi2Sr2CaCu2Ox（Bi-2212）superconducting bulks with better intergrain connections. The influences of the modified SPS process on the microstructures, intergrain connections, and related superconducting properties were systematically analyzed. The modified SPS process can not only increase the final density of the bulk samples but also enhance the texture structures. Clean grain boundaries were obtained instead of the intergrain amorphous layers. Therefore the intergranular properties were obviously improved. Due to the better intergrain connections and the stronger flux pinning properties, the critical current densities of the Bi-2212 bulks obtained via the modified SPS process were greatly increased. The obtained improvements imply the possibility for the modified SPS technique to be used for enhancing the superconducting properties of the Bi-2212 tapes.展开更多
Innovative use of HfO_(2)-based high-dielectric-permittivity materials could enable their integration into few-nanometre-scale devices for storing substantial quantities of electrical charges,which have received wides...Innovative use of HfO_(2)-based high-dielectric-permittivity materials could enable their integration into few-nanometre-scale devices for storing substantial quantities of electrical charges,which have received widespread applications in high-storage-density dynamic random access memory and energy-efficient complementary metal-oxide-semiconductor devices.During bipolar high electric-field cycling in numbers close to dielectric breakdown,the dielectric permittivity suddenly increases by 30 times after oxygen-vacancy ordering and ferroelectric-to-nonferroelectric phase transition of near-edge plasma-treated Hf_(0.5)Zr_(0.5)O_(2) thin-film capacitors.Here we report a much higher dielectric permittivity of 1466 during downscaling of the capacitor into the diameter of 3.85μm when the ferroelectricity suddenly disappears without high-field cycling.The stored charge density is as high as 183μC cm^(−2) at an operating voltage/time of 1.2 V/50 ns at cycle numbers of more than 10^(12) without inducing dielectric breakdown.The study of synchrotron X-ray micro-diffraction patterns show missing of a mixed tetragonal phase.The image of electron energy loss spectroscopy shows the preferred oxygen-vacancy accumulation at the regions near top/bottom electrodes as well as grain boundaries.The ultrahigh dielectric-permittivity material enables high-density integration of extremely scaled logic and memory devices in the future.展开更多
Endogenous elicitor, termed cellulase-degraded cell wall (CDW), was prepared from the cell wall of suspension-cultured ginseng (Panax ginseng C.A. Meyer) cells via cellulase degradation. CDW activated the NADPH oxidas...Endogenous elicitor, termed cellulase-degraded cell wall (CDW), was prepared from the cell wall of suspension-cultured ginseng (Panax ginseng C.A. Meyer) cells via cellulase degradation. CDW activated the NADPH oxidase activity of isolated plasma membranes and stimulated in vivo H2O2 generation in ginseng cell suspensions. CDW also increased the activity of phenylalanine ammonia lyase (PAL), expression of a P. ginseng squalene epoxidase (sqe) gene and saponin synthesis. NADPH oxidase inhibitors inhibited both in vitro NADPH oxidase activity and in vivo H2O2 generation. Induction of PAL activity, saponin synthesis and sqe gene expression were all inhibited by such inhibitor treatments and reduced by incubation with catalase and HA scavengers. These data indicate that activation of NADPH oxidase and generation of H2O2 are essential signalling events mediating defence responses induced by the endogenous elicitor(s) present in CDW.展开更多
基金supported by National Natural Science Foundation of China(Nos.11505019,21173028)the Science and Technology Research Project of Liaoning Provincial Education Department(No.L2013464)+1 种基金the Scientific Research Foundation for the Doctor of Liaoning Province(No.20131004)the Dalian Jinzhou New District Science and Technology Plan Project(No.KJCX-ZTPY-2014-0001)
文摘Cold plasma generated by dielectric barrier discharge （DBD） at atmospheric pressure was adopted for preparation of commercial TiO2 Degussa P25 supported Au catalysts （Au/P25- P） with the assistance of the deposition-precipitation procedure. The influences of the plasma reduction time and calcination on the performance of the Au/P25-P catalysts were investigated. CO oxidation was performed to investigate the catalytic activity of the Au/P25 catalysts. The results show that DBD cold plasma for the fabrication of Au/P25-P catalysts is a fast process, and Au/P25-P （4 min） exhibited the highest CO oxidation activity due to the complete reduction of Au compounds and less consumption of oxygen vacancies. In order to form more oxygen vacancies active species, Au/P25-P was calcined to obtain Au/P25-PC catalysts. Interestingly, Au/P25- PC exhibited the highest activity for CO oxidation among the Au/P25 samples. The results of transmission electron microscopy （TEM） indicated that the smaller size and high distribution of Au nanoparticles are the mean reasons for a high performance of Au/P25-PC. Atmospheric- pressure DBD cold plasma was proved to be of great efficiency in preparing high performance supported Au catalysts.
文摘Modification of poly(tetrafluoroethylene)(PTFE) films with 2-methacryloyloxyethyl phosphorylcholine(MPC) was performed by low-temperature plasma treatment and grafting polymerization.Surface properties of PTFE were characterized by attenuated total reflectance Fourier transform infrared(ATR-FTIR) spectra,X-ray photoelectron spectroscopy(XPS) ,and static contact angle.The results show that MPC has been grafted onto PTFE film surface successfully.Contact angle for the modified PTFE films in the water decreased from 108°to 58.25°,while surface energy increased from 17.52 mN/m to 45.47 mN/m.The effects of plasma treatment time,monomer concentration and grafting time on degree of grafting were determined.In the meanwhile,blood compatibility of the PTFE films was studied by checking thrombogenic time of blood plasma.
文摘Knowledge of plasma composition is very important for various plasma applications and prediction of plasma properties. We use the Saha equation and Debye length equation to calculate the non-local thermodynamic-equilibrium plasma composition. It has been shown that the model to 2T with T representing the temperature （electron temperature and heavy-particle temperature） described by Chen and Han [J. Phys. D 32 （1999）1711] can be applied for a mixture of gases, where each atomic species has its own temperature, but the model to 4T is more general because it can be applicable to temperatures distant enough of the heavy particles. This can occur in a plasma composed of big- or macro-molecules. The electron temperature Te varies in the range 8000＊20000K at atmospheric pressure.
基金supported by the National Natural Science Foundation of China(Grant No.22072010)Natural Science Foundation of Chongqing Municipality(Grant No.CSTB2024NSCQLZX0101)+2 种基金Natural Science Foundation of Chongqing(Grant No.cstc2021ycjh-bgzxm0181)Science and Technology Research Program of Chongqing Municipal Education Commission(Grant No.KJQN202300629)Institute for Advanced Sciences(Grant No.E011A2022325).
文摘To address the issues of the greenhouse effect and energy dilemma,it is a global hot topic on converting CO_(2)to valuable chemicals and useable fuels.In this review,firstly,we shortly summarize different CO_(2)conversion methods including thermal catalysis,biocatalysis,electrocatalysis,photocatalysis,and plasma catalysis.Then,a comprehensive overview of the currently explored plasma driven CO_(2)conversion is presented,such as microwave discharge plasma,gliding arc discharge plasma,radiofrequency inductively coupled plasma,and dielectric barrier discharge plasma,with an emphasis on their experimental setups,achievements and limitations.Furthermore,the activation of CO_(2)conversion via the synergistic effect between the plasma and photocatalyst is discussed in detail.Finally,the associated challenges and future development trends for plasma catalytic CO_(2)conversion are briefly concluded.
基金financially supported by the National Natural Science Foundation of China (Grant No.51975151)the Heilongjiang Provincial Natural Science Foundation of China (Grant No.LH2019E041)Heilongjiang Touyan Team。
文摘Efficient removal of pollutant formaldehyde(HCHO) at room temperature using transition-metal oxides remains a huge challenge to date. Manganese oxide can oxidize formaldehyde, however, how to control the valence states of manganese is the key to further improve the removal efficiency. We have successfully prepared porous manganese oxide nanowires(Mn OxNWs) with large surface area and multiple valence states of manganese using simple electrospinning followed by thermal calcination and potassium permanganate solution post-treatment(C/S process). The contents of trivalent and tetravalent manganese increased significantly after C/S process. Moreover, the composition of silver oxide coated silver nanowires(Ag@Ag_(2) O NWs) is realized by assistance with oxygen plasma, which further enhanced high valence manganese. The formaldehyde removal efficiency by Ag@Ag_(2) O–Mn Oxcomposite nanowires can reach 93.7%. The high-efficient catalytic activity is confirmed to attribute to the higher surface area of composite nanowires, the high-valence manganese and the silver oxide for oxidation of formaldehyde.
文摘Methane conversion in the presence of oxygen under low-temperature radio frequency （RF） plasma was investigated.The experiment results indicated that the following four factors,i.e.,discharge voltage,discharge area,O2/CH4 molar ratio and total gas flowrate,affected remarkably the reaction performance.The optimum reaction conditions of methane conversion in the presence of O2 under RF plasma are as follows：discharge voltage 1050 V,discharge area 989.1mm 2,O2/CH4 molar ratio 1/10 and total gas flowrate 200 ml/min.A methane conversion of 91% could be reached under the optimum conditions.Oxygen is good for the breaking of C-H bonds and also acts as a sort of thinner.According to the low-temperature plasma characteristics,the macroscopic kinetics model of methane conversion in the presence of O2 under radio frequency plasma was studied.
文摘The influence on the effectiveness of sterilization by low-temperature plasma sterilizer CASP-80A was investigated so as to provide a theoretical basis for reducing medical costs and achieving ideal sterilization effectiveness. To conduct the on-site simulation test, a clinical material sterilization test and a test of the influence of organic substance were conducted, the former by using the representative of Bacillus Stearothermophilus, preparing the bacteria-contaminated carrier through polytetrafluoroethylene （PTFE） simulated hose endoscopes, and the latter by using calf serum as the influence factor of the organic substance. The results show that the CASP-80A low-temperature plasma sterilizer could achieve effective sterilization by either the short-cycle or the long-cycle sterilization method depending on different materials, apparatus, and extent of contamination. The organic substances could influence the effectiveness of sterilization by the low-temperature plasma （H2O2） sterilizer.
基金supported by National Natural Science Foundation of China(No.12075037)Research and Application Service Platform Project of API Manufacturing Environmental Protection and Safety Technology in China(No.2020-0107-3-1)。
文摘The plasma catalytic degradation of o-xylene in simulated air was improved by loading low amounts of Pt,Pd,or Au onto Co_(3)O_(4).At room temperature,o-xylene conversion and CO_(x)selectivity using a0.1 wt%Pt/Co_(3)O_(4)catalyst reached 98.9%and 80%,and the energy efficiency was at the top level in comparison with values in the literature.A stable o-xylene degradation performance could be obtained by online regenerating the heat-insulated reactor with a high energy density.After characterization,it was found that the loading of nanosized Pt not only increased the Co^(3+)/Co^(2+)ratio,where the Co^(3+)benefitted the formation of reactive oxygen species,but also conduced Pt^(0)to oxygen activation,resulting in effective promotion of complete o-xylene oxidation.Operando plasma diffuse reflectance infrared Fourier transform spectroscopy demonstrated the complete o-xylene oxidation and proved that Pt played a key role in the complete oxidation of o-xylene.
基金supported by the National Science and Technology Major Project of China(No.HT-J2019-V-0023-0140)Open Project of State Key Laboratory of Advanced Special Steel,Shanghai Key Laboratory of Advanced Ferrometallurgy,Shanghai University(No.SKLASS 2023-03)the Science and Technology Commission of Shanghai Municipality(No.20511107700).
文摘A novel plasma torch nitriding technology was applied for the first time to improve the surface properties of M2 high-speed steel by adjusting different experimental parameters.The nitrogen content,precipitate,microstructure,mechanical property,and corrosion resistance of the nitrided layer were comprehensively analyzed using an ONH analyzer,scanning electron microscope(SEM),micro-area X-ray diffractometer,transmission electron microscope(TEM),Vickers microhardness tester,high-temperature wear tester,3D profilometer,tensile testing machine,and electrochemical workstation.The research results show that the novel plasma torch nitriding technology can achieve synergistic strengthening of nitrogen,carbon,and alloying element solid solution,precipitation strengthening,and martensitic structure on the surface of M2 high-speed steel.The nitrogen content on the specimen surface increased up to 0.17%,while the size and area of carbides were reduced by 89%and 86%,respectively,indicating a transformation towards fine nitrogen-rich precipitates.Compared to the original M2 steel,the nitrided specimens exhibited significant improvements in overall performance.The hardness increased from 228 HV_(0.2)to a maximum of 795 HV_(0.2),the wear coefficient decreased from a maximum of 0.8 to 0.49,the tensile strength increased from 753 MPa to a maximum of 934 MPa,and the corrosion current density decreased from 1.2×10^(−5)to a minimum of 1.9×10^(−6)A/cm^(2).
基金supported by the National Key Research and Development Program of China(2016YFB0301800)the National High Technology Research and Development Program of China(2015AA020201).
文摘The production of medical waste(MW)is a growing concern,particularly in light of the increasing annual generation and the exacerbating effects of the COVID-19 pandemic.Traditional techniques such as incineration and landfilling present significant limitations.In this study,a self-designed 50 kW arc plasma reactor was employed to conduct gasification experiments on nitrile-butadiene rubber(NBR)which served as a model of MWand a mixture of NBR/SiO_(2) which served as a model of glass-containing MW,using CO_(2)as the working gas.The CO_(2)thermal plasma gasification process not only ensures the safe and efficient disposal of MW,but also facilitates its effective conversion into H_(2)and CO,achieving a carbon conversion efficiency of 94.52%.The yields of H2 and CO reached 98.52%and 81.83%,respectively,and the specific energy consumption was as low as 3.55 kW·h·kg^(-1).Furthermore,the addition of SiO_(2) was found to inhibit the gasification of NBR and cause damage to the reactor.Therefore,it is recommended that glass waste should be removed prior to the treatment of MW.The CO_(2)thermal plasma gasification technology can not only eliminate environmental and health risks posed by MW,but also convert it into syngas for further utilization.This provides a promising approach to the harmless and resource disposal of MW,while also contributing to the comprehensive utilization of greenhouse gases.
基金financially supported by the VLAIO-Catalisti ICON project"Blue Plasma"(grant ID HBC.2022.0445)by the European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation program(Grant Agreement No.810182–SCOPE ERC Synergy project)the Horizon Europe Research and Innovation Action(Grant Agreement No.101172766—EffiTorch)。
文摘We present the performance of a post-plasma carbon bed for improving plasma-based CO_(2)conversion,studying the effect of bed length and additional thermal bed insulation.The experiments were conducted using an atmospheric pressure gliding arc plasmatron in both high and low specific energy input(SEI)regimes.Each bed was equipped with a silo to enable continuous carbon feeding and operation for an order of 1 h,thus overcoming previous limitations in literature.Importantly,we derive an improved energy efficiency(EE)calculation with an accurate and unambiguous consideration of the key reaction contributions of both plasma and carbon bed.This derivation serves to highlight the inconsistencies that arise in determining EE in such a complex chemical system.We therefore advise and advocate for the use of energy cost(EC)as the key reported energy metric in systems using post-plasma carbon beds.The optimum conversion and energy metrics were obtained with the longest bed,reaching a conversion of 41%,an EE of 51%and an EC of 0.41 MJ/mol at high SEI.The design of the insulated bed and silo allow for previously unreported preheating of the carbon,which reduces oscillations observed in the conversion profiles of the short and long beds.Preheating of the external silo for the long bed also yields a near-complete removal of oscillations.Finally,when comparing our performance with results from literature for postplasma carbon beds,our system clearly improves upon the state-of-the-art,both in absolute values of conversion and energy metrics at the same SEI,as well as by sustaining this improvement for extended periods of time.
基金Guangzhou (China) government postdoctoral program for providing financial support to conduct this worksupport from the National Natural Science Foundation of China (No. 72140008)funding from the European Union’s Horizon 2020 Research and Innovation program under grant agreement No. 101022484。
文摘Graphene has enormous potential to capture CO_(2)due to its unique properties and cost-effectiveness.However,graphene-based adsorbents have drawbacks of lower CO_(2)adsorption capacity and poor selectivity.This work demonstrates a one-step rapid and sustainable N_(2)/H_(2)plasma treatment process to prepare graphene-based sorbent material with enhanced CO_(2)adsorption performance.Plasma treatment directly enriches amine species,increases surface area,and improves textural properties.The CO_(2)adsorption capacity increases from 1.6 to 3.3 mmol/g for capturing flue gas,and from 0.14 to 1.3 mmol/g for direct air capture (DAC).Importantly,the electrothermal property of the plasma-modified aerogels has been significantly improved,resulting in faster heating rates and significantly reducing energy consumption compared to conventional external heating for regeneration of sorbents.Modified aerogels display improved selectivity of 42 and 87 after plasma modification for 5 and 10 min,respectively.The plasma-treated aerogels display minimal loss between 17%and 19% in capacity after 40 adsorption/desorption cycles,rendering excellent stability.The N_(2)/H_(2)plasma treatment of adsorbent materials would lower energy expenses and prevent negative effects on the global economy caused by climate change.
基金supported by the National Natural Science Foundation of China(51802031)the research startup fund from Jiangsu Second Normal University
文摘Molybdenum disulfide(MoS_(2))is identified as one of the most prospective anode materials for sodium ion batteries due to the special layer structure,high working potential and high theoretical capacity.Herein,N-doped MoS_(2)nanosheets vertically grown on Ti_(3)C_(2)layers named as N-MoS_(2)-Ti_(3)C_(2)composite has been synthesized by N plasma treatment on MoS_(2)-Ti_(3)C_(2)composite at room temperature.In sodium ion batteries,the N-MoS_(2)-Ti_(3)C_(2)electrode exhibited the initial capacity of 294.2 mAh·g^(−1)at 1 A·g^(−1),and maintained a stable specific capacity of 209.3 mAh·g^(−1)after 500 cycles,better than that of MoS_(2)-Ti_(3)C_(2)(79.0 mAh·g^(−1))and MoS_(2)(30.8 mAh·g^(−1)).The greatly enhanced high rate cycle performance for N-MoS_(2)-Ti_(3)C_(2)can be attributed to the N doping in MoS_(2)and Ti_(3)C_(2).
基金supported by the National Natural Science Foundation of China (Nos.52260013,51968034,and 21876071)the Yunnan Major Scientific and Technological Projects (No.202202AG050005).
文摘In this study,non-thermal plasma(NTP)was employed to modify the Cu/TiO_(2)adsorbent to efficiently purify H_(2)S in low-temperature and micro-oxygen environments.The effects of Cu loading amounts and atmospheres of NTP treatment on the adsorption-oxidation performance of the adsorbents were investigated.The NTP modification successfully boosted the H_(2)S removal capacity to varying degrees,and the optimized adsorbent treated by air plasma(Cu/TiO_(2)-Air)attained the best H_(2)S breakthrough capacity of 113.29 mg H_(2)S/gadsorbent,which was almost 5 times higher than that of the adsorbent without NTP modification.Further studies demonstrated that the superior performance of Cu/TiO_(2)-Air was attributed to increased mesoporous volume,more exposure of active sites(CuO)and functional groups(amino groups and hydroxyl groups),enhanced Ti-O-Cu interaction,and the favorable ratio of active oxygen species.Additionally,the X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS)results indicated the main reason for the deactivationwas the consumption of the active components(CuO)and the agglomeration of reaction products(CuS and SO_(4)^(2−))occupying the active sites on the surface and the inner pores of the adsorbents.
基金financially supported by the National Natural Science Foundation of China(Nos.52171120,52271106,52071188)the Natural Science Foundation of Zhejiang Province,China(No.LZY23E050001)。
文摘Ti_(2)AlC/TiAl composites with a network structure were successfully prepared with carbon nanotubes and Ti-45Al-8Nb pre-alloyed powder using spark plasma sintering.The effects of sintering temperature(1200-1350℃)on the microstructural evolution and mechanical properties were systematically investigated.The microstructure of Ti_(2)AlC/TiAl composites exhibits duplex,near-lamellar,and fully lamellar structures,as the sintering temperature increases from 1200 to 1350℃.The network structured Ti_(2)AlC phase can refine the microstructure and the phase becomes discontinuous at high sintering temperatures.Notably,composites sintered at 1300℃ exhibit excellent mechanical properties,with the highest compressive strength(1921 MPa)and fracture strain(26%)at room temperature.Moreover,the ultimate tensile strength and fracture strain reach 537 MPa and 3.1%at 900℃,and 485 MPa and 3.3%at 950℃,respectively.The enhancement of the mechanical properties is attributed primarily to the load bearing,particle pull-out,and inhibition of crack propagation induced by Ti_(2)AlC particles.
基金Project supported by the National Basic Research Program of China(Grant No.2011CBA00104)the National Natural Science Foundation of China(Grant No.51472206)+1 种基金the ITER Project of China(Grant No.2013GB110001)the Program for Innovative Research Team in Shaanxi Province,China(Grant No.2013KCT-07)
文摘A modified spark plasma sintering（SPS） technique was developed for the fabrication of Bi2Sr2CaCu2Ox（Bi-2212）superconducting bulks with better intergrain connections. The influences of the modified SPS process on the microstructures, intergrain connections, and related superconducting properties were systematically analyzed. The modified SPS process can not only increase the final density of the bulk samples but also enhance the texture structures. Clean grain boundaries were obtained instead of the intergrain amorphous layers. Therefore the intergranular properties were obviously improved. Due to the better intergrain connections and the stronger flux pinning properties, the critical current densities of the Bi-2212 bulks obtained via the modified SPS process were greatly increased. The obtained improvements imply the possibility for the modified SPS technique to be used for enhancing the superconducting properties of the Bi-2212 tapes.
基金supported by the National Key Basic Research Program of China (2022YFA1402904)Basic Research Project of Shanghai Science and Technology Innovation Action (grant number 24CL2900900)the National Natural Science Foundation of China (grant number 61904034)
文摘Innovative use of HfO_(2)-based high-dielectric-permittivity materials could enable their integration into few-nanometre-scale devices for storing substantial quantities of electrical charges,which have received widespread applications in high-storage-density dynamic random access memory and energy-efficient complementary metal-oxide-semiconductor devices.During bipolar high electric-field cycling in numbers close to dielectric breakdown,the dielectric permittivity suddenly increases by 30 times after oxygen-vacancy ordering and ferroelectric-to-nonferroelectric phase transition of near-edge plasma-treated Hf_(0.5)Zr_(0.5)O_(2) thin-film capacitors.Here we report a much higher dielectric permittivity of 1466 during downscaling of the capacitor into the diameter of 3.85μm when the ferroelectricity suddenly disappears without high-field cycling.The stored charge density is as high as 183μC cm^(−2) at an operating voltage/time of 1.2 V/50 ns at cycle numbers of more than 10^(12) without inducing dielectric breakdown.The study of synchrotron X-ray micro-diffraction patterns show missing of a mixed tetragonal phase.The image of electron energy loss spectroscopy shows the preferred oxygen-vacancy accumulation at the regions near top/bottom electrodes as well as grain boundaries.The ultrahigh dielectric-permittivity material enables high-density integration of extremely scaled logic and memory devices in the future.
文摘Endogenous elicitor, termed cellulase-degraded cell wall (CDW), was prepared from the cell wall of suspension-cultured ginseng (Panax ginseng C.A. Meyer) cells via cellulase degradation. CDW activated the NADPH oxidase activity of isolated plasma membranes and stimulated in vivo H2O2 generation in ginseng cell suspensions. CDW also increased the activity of phenylalanine ammonia lyase (PAL), expression of a P. ginseng squalene epoxidase (sqe) gene and saponin synthesis. NADPH oxidase inhibitors inhibited both in vitro NADPH oxidase activity and in vivo H2O2 generation. Induction of PAL activity, saponin synthesis and sqe gene expression were all inhibited by such inhibitor treatments and reduced by incubation with catalase and HA scavengers. These data indicate that activation of NADPH oxidase and generation of H2O2 are essential signalling events mediating defence responses induced by the endogenous elicitor(s) present in CDW.
