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degradation:A critical challenge for M-N-C electrocatalysts

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Journal of Energy Chemistry 2021年第12期30卷 667-674,I0016页

作者： Yongchao Yang Leo Lai Li Wei Yuan Chen School of Chemical and Biomolecular Engineering The University of Sydney.DarlingtonNew South Wales 2006Australia

Atomically dispersed transition metal(M)and nitrogen(N)co-doped carbon(M-N-C)electrocatalysts hold excellent application potentials for several critical reactions required in electrochemical conversion processes and energy storage devices,including oxygen reduction reaction,oxygen evolution reaction,hydrogen evolution reaction,carbon dioxide reduction reaction and nitrogen reduction *** significant progress achieved in the past few decades,their commercialization is hindered by their fast *** perspective article outlines the historical development of M-N-C electrocatalysts,the current understanding of their active catalytic sites,and crucial degradation *** highlight that many methods used to tailor M-N-C electrocatalysts likely cause contradictory effects on activity and *** emphasis is needed to address their degradation issues under industryrelevant working conditions.

关键词： M-N-C Transition metal Electrocatalyst degradation

degradation of sulfamethoxazole in water by dielectric barrier discharge plasma jet:influencing parameters,degradation pathway,toxicity evaluation

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Plasma Science and Technology 2023年第3期25卷 204-216页

作者：胡淑恒燕维文喻金明朱斌兰彦奚文灏许子牧韩伟程诚 School of Resources and Environmental Engineering Hefei University of TechnologyHefei 230009People’s Republic of China Institute of Plasma Physics Chinese Academy of SciencesHefei 230031People’s Republic of China Institute of Energy Hefei Comprehensive National Science CenterHefei 230031People’s Republic of China Institute of Health and Medical Technology/Anhui Province Key Laboratory of Medical Physics and Technology Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031People’s Republic of China

Sulfamethoxazole(SMX)is an antibiotic and widely present in aquatic environments,so it presents a serious threat to human health and sustainable development.A dielectric barrier discharge(DBD)plasma jet was utilized to degrade aqueous SMX,and the effects of various operating parameters(working gas,discharge power,etc)on SMX degradation performance were *** experimental results showed that the DBD plasma jet can obtain a relatively high degradation efficiency for SMX when the discharge power is high with an oxygen atmosphere,the initial concentration of SMX is low,and the aqueous solution is under acidic *** reactive species produced in the liquid phase were detected,and OH radicals and O3were found to play a significant role in the degradation of ***,the process of SMX degradation could be better fitted by the quasi-first-order reaction kinetic *** analysis of the SMX degradation process indicated that SMX was gradually decomposed and 4-amino benzene sulfonic acid,benzene sulfonamide,4-nitro SMX,and phenylsulfinyl acid were detected,and thus three possible degradation pathways were finally *** mineralization degree of SMX reached 90.04%after plasma treatment for 20 min,and the toxicity of the solution fluctuated with the discharge time but eventually decreased.

关键词： dielectric barrier discharge(DBD)plasma jet sulfamethoxazole(SMX) degradation pathway toxicity

degradation of Alizarin Red by Hybrid Gas-Liquid Dielectric Barrier Discharge

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Plasma Science and Technology 2014年第11期16卷 1036-1041页

作者：林启富倪国华江贻满吴文伟孟月东 Institute of Plasma Physics Chinese Academy of Sciences

A system based on dielectric barrier discharge （DBD） with improved discharge sta- bility and homogeneity was used for the degradation of Alizarin Red （AR）. This special structure of the DBD system is characterized by the high voltage electrode, which is covered with a quartz tube and partially immersed in water, and by directly using the water as the ground electrode. A transition was realized from the filamentary mode for the conventional structure of the DBD to the semi-homogeneous mode for such a configuration of the plasma discharge. The spectra of plasma are dominated by N2 molecular lines in the ultraviolet-A radiation region. Plasma degra- dation of AR in this system exhibited pseudo-first-order reaction kinetics. The degradation rate of AR reached 95% or so after 14 min treatment under favorable conditions. Alkaline conditions are favorable for the degradation of AR. The increase of conductivity of the solution, input power and usage of oxygen bubbling could enhance AR degradation.

关键词： water purification degradation alizarin red dielectric barrier discharge

degradation of PCDD/Fs in MSWI fly ash using a microwave-assisted hydrothermal process

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Chinese Journal of Chemical Engineering 2019年第7期27卷 1708-1715页

作者： Qili Qiu Xuguang Jiang Guojun Lü Zhiliang Chen Shengyong Lu Mingjiang Ni Jianhua Yan Xiaobing Deng State Key Laboratory of Clean Energy Utilization Zhejiang UniversityHangzhou 310027China Hangzhou Lijia Environmental Services Co. Ltd.Hangzhou 311101China

In this work,microwave treatment was introduced to a hydrothermal treatment process to degrade PCDD/Fs(Polychlorinated dibenzo-p-dioxins and dibenzofurans)in municipal solid waste incineration(MSWI)fly *** process additives(NaOH,Na2 HPO4,H2 O),temperatures(150℃,185℃,220℃)and reaction times(1 h,2 h,3 h)were investigated to identify their effect on the disposal of fly ash samples through orthogonal ***-resolution gas chromatography–mass spectrometry(HRGC/MS)was applied to determine the PCDD/F concentrations in MSWI fly *** experimental results revealed that 83.7%of total PCDD/Fs was *** temperature was the most important factor for the degradation of the total PCDD/*** direct destruction and chlorination reactions(the chlorination degree of PCDFs increased)took part in the degradation of PCDD/Fs in fly ash,which was a new *** PCDD/F indexes determined by the concentration of indicative congeners were found to quantitatively characterize the dioxin toxicity of the fly ***,heavy metals in the fly ash sample were solidified using microwave-assisted hydrothermal treatment,which provided an experimental basis for the simultaneous disposal of dioxins and heavy ***,the microwave-assisted hydrothermal process should be considered for the future disposal of MSWI fly ash.

关键词： Dioxins degradation MSWI fly ash Hydrothermal treatment Microwave

degradation of a discrete infilled joint shear strength subjected to repeated blast-induced vibrations

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International Journal of Mining Science and Technology 2018年第4期28卷 560-570页

作者： Siamaki Ali Esmaieli Kamran Mohanty Bibhu Lassonde Institute of Mining University of Toronto

This paper presents the results of a series of numerical modeling experiments aimed at quantifying blast- induced degradation of shear strength of discontinuities. Near-field vibration history of a single-row pro- duction blast in a. limestone quarry was used as input to the nu .merical model. For this. purpose, two rock blocks, representing a stiff massive sulfide rock and a weaker limestone rock, were simulated using the 2D Particle Flow Code （PFC2D）. Rock mass conta!ning a single inclined joint was modeled as Mohr- Coulomb. The results show that the crack generation rate is increased in both samples after repetitive vibration loading. Joint shear strength degradation rate in !he stiffer massive sulfide rock sample is higher than the softer limestone rock, which is attributed to the higher seismic impedance mismatch. The results show that even low-amplitude blasting vibrations （〈80 mm/s）, when repeated as in multi-hole blasts, can significantly degrade joint shear strength in the nearby pit walls.

关键词： Blasting Vibration PFC2D Discontinuity Rock degradation

degradation of the transconductance of a gate-modulated generation current in nMOSFET

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Chinese Physics B 2012年第8期21卷 564-569页

作者：陈海峰过立新杜慧敏 School of Electronic Engineering Xi'an University of Posts and Telecommunications

The degradation of transconductance （G） of a gate-modulated generation current IGD in a LDD nMOSFET is investigated. The G curve shifts rightward under the single electron-injection-stress （EIS）. The trapped electrons located in the gate oxide over the LDD region （QL） makes the effective drain voltage diminish. Accordingly, the G peak in depletion （GMD） and that in weak inversion （GMw） decrease. It is found that △GMD and △GMw each have a linear relationship with the n-th power of stress time （tn） in a dual-log coordinate： △GMD octn, AGMD octn （n = 0.25）. During the alternate stress, the injected holes neutralize QL induced by the previous EIS. This neutralization makes the effective VD restore to the initial value and then the IGD peak recovers completely. Yet the threshold voltage recovery is incomplete due to the trapped electron located over the channel （Qc）. As a result, GMW only recovers to circa 50% of the initial value after the hole-injection-stress （HIS）. Instead, GMD almost recovers. The relevant mechanisms are given in detail.

关键词： generation current transconductance electron injection alternate stress degradation

degradation of simulated organic wastewater by advanced oxidation with oxidants generated from oxygen reduction

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Chinese Journal of Chemical Engineering 2019年第4期27卷 850-856页

作者： Yi Ouyang Qing Xu Yang Xiang Wei Liu Junqi Du Beijing Key Laboratory of Membrane Science and Technology Beijing University of Chemical Technology Beijing 100029 China School of Chemical Engineering Beijing University of Chemical Technology Beijing 100029 China

The degradation capacity of advanced oxidants generated from oxygen reduction was investigated in model effluent containing chlorobenzene, aniline and benzene through the advanced oxidation processes(AOPs). Intermediate products of the degradation process were determined by GC–MS, and they contributed to specify the degradation pathways of monoaromatic compounds. The study particularly focused on the influence of the dosage of the oxidant, pH and the initial concentration of organic compounds on the degradation *** the dosage of oxidant was 4 wt% and the pH was 7, the maximum degradation rates of 74.83% chlorobenzene, 70.32% aniline and 37.69% benzene were achieved. Furthermore, microwave was applied to intensify the oxidation process under optimal operation conditions, and the degradation rates were increased to 87.85% chlorobenzene, 89.11% aniline and 39.03% benzene, respectively.

关键词： AOPs degradation Advanced oxidants Monoaromatic compounds Microwave

degradation Diagnostics from the Subsurface of Lithium-Ion Battery Electrodes

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Energy & Environmental Materials 2022年第2期5卷 662-669页

作者： Xuhui Yao Tomas Samoril JiriDluhos John F.Watts Zhijia Du Bohang Song SRavi P.Silva Tan Sui Yunlong Zhao Advanced Technology Institute University of SurreyGuildford Surrey GU27XHUK TESCAN ORSAY HOLDING a.s.Libusina tr.21Brno 62300Czech Republic Department of Mechanical Engineering Sciences University of SurreyGuildford Surrey GU27XHUK Energy and Transportation Science Division Oak Ridge National LaboratoryOak Ridge TN 37830USA Neutron Scattering Division Oak Ridge National LaboratoryOak Ridge TN 37830USA National Physical Laboratory Teddington Middlesex TW110LWUK

Despite the long-established rocking-chair theory of lithium-ion batteries(LIBs),developing novel characterization methodology with higher spatiotemporal resolution facilitates a better understanding of the solid electrolyte interphase studies to shape the reaction *** this work,we develop a Xenon ion plasma focused ion beam(Xe+PFIB)-based characterization technique to probe the cross-sectional interface of both ternary cathode and graphite anode electrodes,with the focus on revealing the chemical composition and distribution underneath the electrode surface by in-depth analysis of secondary ***,the lithium fluoride is detected in the pristine cathode prior to contact with the electrolyte,reflecting that the electrode degradation is in the form of the loss of lithium inventory during electrode *** degradation is related to the hydrolysis of the cathode material and the decomposition of the PVDF *** the quantitative analysis of the transition-metal degradation products,manganese is found to be the dominant element in the newly formed inactive fluoride deposition on the cathode,while no transition metal signal can be found inside the anode *** insights at high resolution implemented via a PFIB-based characterization technique not only enrich the understanding of the degradation mechanism in the LIBs but also identify and enable a high-sensitivity methodology to obtain the chemical survey at the subsurface,which will help remove the capacity-fade observed in most LIBs.

关键词： degradation lithium-ion battery mass spectrometry plasma focused ion beam subsurface

degradation of Populus euphratica community in the lower reaches of the Tarim River, Xinjiang, China

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Journal of Environmental Sciences 2005年第5期17卷 740-747页

作者： LIU Jia-zhen CHEN Ya-ning CHEN Yong-jin ZHANG Na LI Wei-hong Xinjiang Institnte of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China Graduate School of Chinese Academy of Sciences Beijing 100039 China

To investigate the relationships between the degradation of plant community and groundwater level in the lower reaches of the Tarim River, nine monitored sections were set along the main stream, where there had been no runoff for nearly 30 years. The characteristics of plant communities were analyzed. It was found that the coverage of trees gradually decreased along the groundwater depth gradient, while the coverage of shrubs slightly increased rather than decreased at first and then gradually decreased, and the coverage of herbs steadily decreased at the beginning and then quickly decreased. The species diversity and species richness of both herbs and woody plants showed obvious degrading trends, while the variations in species evenness were slight. The degrading sequences of species were related to their physiological and ecological characteristics, especially their sensitivity to changes of groundwater table. The herbs with shallow roots first degenerated or disappeared when the groundwater table fell, and then did the deep-rooted herbs, and finally the trees and shrubs with strong tolerance to drought degenerated. The Populus euphratica communities showed typical degrading characteristics, namely the dominant species Populus euphratica remained its dominant status during the degradation. Overall, the existence of strongly tolerant-drought species was the obvious indication of plant species degradation; while simplification of community structure and the decrease of species richness were the obvious indication of plant community degradation.

关键词： degradation plant community coverage species diversity Tarim River