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
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
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
The high-quality gate dielectric on silicon carbide(SiC)surface is critical to fabricate high-performance SiC metal-oxide-semiconductor field-effect transistors(MOSFETs).This research employs microwave plasma annealin...The high-quality gate dielectric on silicon carbide(SiC)surface is critical to fabricate high-performance SiC metal-oxide-semiconductor field-effect transistors(MOSFETs).This research employs microwave plasma annealing(MPA)to obtain high-quality Al_(2)O_(3)/SiC gate stacks.By designing MPA atmosphere and optimizing the plasma power,the SiC MOS capacitor with a Al_(2)O_(3)dielectric film shows the enhanced performance.The interface state density is reduced by 1 order of magnitude to 6×10^(11)cm^(-2)·eV^(-1),the breakdown electric field is increased,and the voltage shift is effectively suppressed Besides,the mechanism of MPA process is discussed in terms of the thermal effect and reactant species.X-ray photoelectron spectroscopy(XPS)results unveil oxygen plasma plays the main role.Optimal plasma power during the MPA process results in defect repairs of the firstneighbor Al-O bonding and partial removal of Al-O-H bond from the interface region.This study demonstrates that MPA process is an effective option to realize highquality dielectric and interface on SiC.展开更多
The poor reversibility of Zn anodes induced by dendrite growth,surface passivation,and corrosion,severely hinders the practical applicability of Zn metal batteries.To address these issues,a plasmaassisted aerogel(PAG)...The poor reversibility of Zn anodes induced by dendrite growth,surface passivation,and corrosion,severely hinders the practical applicability of Zn metal batteries.To address these issues,a plasmaassisted aerogel(PAG)interface engineering was proposed as efficient ion transport modulator that can simultaneously regulate uniform Zn^(2+)flux and desolvation behavior during battery operation.The PAG with ordered mesopores acted as an ion sieve to homogenize Zn deposition and accelerate Zn^(2+)flux,which is favorable for corrosion resistance and dendrite suppression.Importantly,the plasma-assisted aerogel with abundant hydrophilic groups can facilitate the desolvation kinetics of Zn^(2+)due to the multiple hydrogen-bonding interaction with the activated water molecules,thus accelerating the Zn^(2+)migration kinetics.Consequently,the Zn/Zn cell assembled with PAG-modified separator demonstrates stable plating and stripping behavior(over 1400 h at 1 mA cm^(-2))and high Coulombic efficiency(99.8%at1 mA cm^(-2)after 1100 cycles),and the Zn‖MnO_(2)full cell shows excellent long-term cycling stability and maintains a high capacity of 154.9 mA h g^(-1)after 1000 cycles at 1 A g^(-1).This study provides a feasible approach for the large-scale fabrication of aerogel functionalized separators to realize ultra-stable Zn metal batteries.展开更多
低温等离子体(Low temperature plasma,LTP)可以将热力学稳定的CO_(2)和H_(2)O转化为高附加值产物,在CO_(2)资源化利用和能源转化等领域有广阔前景,但是H_(2)O的强猝灭效应使得LTP转化CO_(2)/H_(2)O的性能提升极具挑战。本文综述了LTP转...低温等离子体(Low temperature plasma,LTP)可以将热力学稳定的CO_(2)和H_(2)O转化为高附加值产物,在CO_(2)资源化利用和能源转化等领域有广阔前景,但是H_(2)O的强猝灭效应使得LTP转化CO_(2)/H_(2)O的性能提升极具挑战。本文综述了LTP转化CO_(2)/H_(2)O的研究进展,包括LTP转化CO_(2)/H_(2)O的反应动力学,以及不同LTP、催化剂、反应器对CO_(2)/H_(2)O转化性能的影响。通过对转化性能和反应机理分析,发现H_(2)O对电子的强吸附效应、产物复合反应和H原子的低密度、副反应的竞争分别是抑制原料气转化率和高附加值产物选择性的关键。针对上述问题,本文从反应器优化、引入其他反应物、催化剂设计和串联催化四个方面,提出性能提升策略。最后,对LTP转化CO_(2)/H_(2)O的重点研究方向进行了展望。展开更多
A laser lap welding process for zinc-coated steel has a well-known unsolved problem-porosity formation. The boiling temperature of coated zinc is lower than the melting temperature of the base metal, which is steel. I...A laser lap welding process for zinc-coated steel has a well-known unsolved problem-porosity formation. The boiling temperature of coated zinc is lower than the melting temperature of the base metal, which is steel. In the autogenous laser welding, the zinc vapor generates from the lapped surfaces expels the molten pool and the expulsion causes numerous weld defects, such as spatters and blow holes on the weld surface and porosity inside the welds. The laser-arc hybrid welding was suggested as an alternative method for the laser lap welding because the arc can preheat or post-beat the weldment according to the arrangement of the laser beam and the arc. CO2 laser-micro plasma hybrid welding was applied to the lap welding of zinc-coated steel with zero-gap. The relationships among the weld quality and process parameters of the laser-arc arrangement, and the laser-arc interspacing distance and arc current were investigated using a full-factorial experimental design. The effect of laser-arc arrangement is dominant because the leading plasma arc partially melts the upper steel sheets and vaporizes or oxidizes the coated zinc on the lapped surfaces. Compared with the result from the laser-TIG hybrid welding, the heat input from arc can be reduced by 40%.展开更多
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 (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financially supported by Beijing Municipal Natural Science Foundation(No.4234091)the National Natural Science Foundation of China(Nos.62304245,61974159,62174176,62174122 and U2241244)+1 种基金the Scientific Instrument Developing Project of the Chinese Academy of Sciences(No.YJKYYQ20200039)the Out-standing Member Project of the Youth Innovation Promotion Association of CAS(No.Y2021046)。
文摘The high-quality gate dielectric on silicon carbide(SiC)surface is critical to fabricate high-performance SiC metal-oxide-semiconductor field-effect transistors(MOSFETs).This research employs microwave plasma annealing(MPA)to obtain high-quality Al_(2)O_(3)/SiC gate stacks.By designing MPA atmosphere and optimizing the plasma power,the SiC MOS capacitor with a Al_(2)O_(3)dielectric film shows the enhanced performance.The interface state density is reduced by 1 order of magnitude to 6×10^(11)cm^(-2)·eV^(-1),the breakdown electric field is increased,and the voltage shift is effectively suppressed Besides,the mechanism of MPA process is discussed in terms of the thermal effect and reactant species.X-ray photoelectron spectroscopy(XPS)results unveil oxygen plasma plays the main role.Optimal plasma power during the MPA process results in defect repairs of the firstneighbor Al-O bonding and partial removal of Al-O-H bond from the interface region.This study demonstrates that MPA process is an effective option to realize highquality dielectric and interface on SiC.
基金financially supported by the National Natural Science Foundation of China(NSFC)(52203261)Natural Science Foundation of Jiangsu Province(BK20210474)the project of research on the industrial application of"controllable synthesis of nanocarbon-based polymer composites and their application in new energy”(N0.CJGJZD20210408092400002).
文摘The poor reversibility of Zn anodes induced by dendrite growth,surface passivation,and corrosion,severely hinders the practical applicability of Zn metal batteries.To address these issues,a plasmaassisted aerogel(PAG)interface engineering was proposed as efficient ion transport modulator that can simultaneously regulate uniform Zn^(2+)flux and desolvation behavior during battery operation.The PAG with ordered mesopores acted as an ion sieve to homogenize Zn deposition and accelerate Zn^(2+)flux,which is favorable for corrosion resistance and dendrite suppression.Importantly,the plasma-assisted aerogel with abundant hydrophilic groups can facilitate the desolvation kinetics of Zn^(2+)due to the multiple hydrogen-bonding interaction with the activated water molecules,thus accelerating the Zn^(2+)migration kinetics.Consequently,the Zn/Zn cell assembled with PAG-modified separator demonstrates stable plating and stripping behavior(over 1400 h at 1 mA cm^(-2))and high Coulombic efficiency(99.8%at1 mA cm^(-2)after 1100 cycles),and the Zn‖MnO_(2)full cell shows excellent long-term cycling stability and maintains a high capacity of 154.9 mA h g^(-1)after 1000 cycles at 1 A g^(-1).This study provides a feasible approach for the large-scale fabrication of aerogel functionalized separators to realize ultra-stable Zn metal batteries.
文摘低温等离子体(Low temperature plasma,LTP)可以将热力学稳定的CO_(2)和H_(2)O转化为高附加值产物,在CO_(2)资源化利用和能源转化等领域有广阔前景,但是H_(2)O的强猝灭效应使得LTP转化CO_(2)/H_(2)O的性能提升极具挑战。本文综述了LTP转化CO_(2)/H_(2)O的研究进展,包括LTP转化CO_(2)/H_(2)O的反应动力学,以及不同LTP、催化剂、反应器对CO_(2)/H_(2)O转化性能的影响。通过对转化性能和反应机理分析,发现H_(2)O对电子的强吸附效应、产物复合反应和H原子的低密度、副反应的竞争分别是抑制原料气转化率和高附加值产物选择性的关键。针对上述问题,本文从反应器优化、引入其他反应物、催化剂设计和串联催化四个方面,提出性能提升策略。最后,对LTP转化CO_(2)/H_(2)O的重点研究方向进行了展望。
文摘A laser lap welding process for zinc-coated steel has a well-known unsolved problem-porosity formation. The boiling temperature of coated zinc is lower than the melting temperature of the base metal, which is steel. In the autogenous laser welding, the zinc vapor generates from the lapped surfaces expels the molten pool and the expulsion causes numerous weld defects, such as spatters and blow holes on the weld surface and porosity inside the welds. The laser-arc hybrid welding was suggested as an alternative method for the laser lap welding because the arc can preheat or post-beat the weldment according to the arrangement of the laser beam and the arc. CO2 laser-micro plasma hybrid welding was applied to the lap welding of zinc-coated steel with zero-gap. The relationships among the weld quality and process parameters of the laser-arc arrangement, and the laser-arc interspacing distance and arc current were investigated using a full-factorial experimental design. The effect of laser-arc arrangement is dominant because the leading plasma arc partially melts the upper steel sheets and vaporizes or oxidizes the coated zinc on the lapped surfaces. Compared with the result from the laser-TIG hybrid welding, the heat input from arc can be reduced by 40%.
