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MoP nanoparticles encapsulated in n-doped carbon nanotubes as sulfur host for advanced lithium-sulfur batteries

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nano Research 2024年第4期17卷 2736-2745页

作者： Guozhi Wu Shanqing Li Zheng Chen Ajiao Sun Jie Yang Sang Woo Joo Jiarui Huang Key Laboratory of Functional Molecular Solids of the Ministry of Education Anhui Laboratory of Molecule-Based MaterialsCollege of Chemistry and Materials ScienceAnhui Normal UniversityWuhu 241002China Anhui Engineering Research Center of Highly Reactive Micro-nano Powders School of Materials and Environmental engineeringChizhou UniversityChizhou 247000China School of Mechanical Engineering Yeungnam UniversityGyeongsanGyeongbuk 38541Republic of Korea

The low electrical conductivity of sulfur,strong volume expansion,shuttle effect,and sluggish redox reactions in Li-S batteries limit their practical *** nanoparticles encapsulated in nitrogen-doped carbon nanotubes(MoP/nC nTs)were synthesized using MoO_(3) nanorods as templates via a polypyrrole coating,heat-carbonization,MoO_(3) partial reduction,ammonia washing,and *** MoP/nC nTs had a hollow nanostructure with a high specific surface area,which can alleviate the volume expansion of the cathode and the shuttle effect of *** encapsulated MoP nanoparticles can anchor the polysulfides and enhance the redox reaction ***,the MoP/nC nTs combined with sulfur(MoP/S/nC nTs)exhibited 440.8 mAh·g^(-1) over 500 cycles at 1.0 A·g^(-1) with a decay rate of 0.06%per *** density functional theory calculations and X-ray photoelectron spectroscopy results confirmed that MoP/nC nTs could anchor polysulfides and alleviate the shuttle effect by chemical *** study supplies a novel route to prepare nanoparticle-embedded in n-doped carbon nanotubes for advanced Li-S battery.

关键词： MoP n-doped carbon nanotube lithium-sulfur battery cathode

Oxidation Evolution and Activity Origin of n-doped carbon in the Oxygen Reduction Reaction

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Transactions of Tianjin University 2024年第4期30卷 369-379页

作者： Jiaqi Wu Chuanqi Cheng Shanshan Lu Bin Zhang Yanmei Shi Department of Chemistry School of ScienceInstitute of Molecular PlusTianjin UniversityTianjin 300072China School of Materials Science and Engineering Institute of New Energy MaterialsTianjin UniversityTianjin 300072China Tianjin Key Laboratory of Molecular Optoelectronic Science Collaborative Innovation Center of Chemical Science and EngineeringTianjin 300072China

n-doped carbon materials,with their applications as electrocatalysts for the oxygen reduction reaction(ORR),have been extensively ***,a negletcted fact is that the operating potential of the ORR is higher than the theoretical oxida-tion potential of carbon,possibly leading to the oxidation of carbon ***,the infl uence of the structural oxidation evolution on ORR performance and the real active sites are not *** this study,we discover a two-step oxida-tion process of n-doped carbon during the *** fi rst oxidation process is caused by the applied potential and bubbling oxygen during the ORR,leading to the oxidative dissolution of n and the formation of abundant oxygen-containing functional *** oxidation process also converts the reaction path from the four-electron(4e)ORR to the two-electron(2e)***,the enhanced 2e ORR generates oxidative H_(2)O_(2),which initiates the second stage of oxidation to some newly formed oxygen-containing functional groups,such as quinones to dicarboxyls,further diversifying the oxygen-containing functional groups and making carboxyl groups as the dominant *** also reveal the synergistic eff ect of multiple oxygen-containing functional groups by providing additional opportunities to access active sites with optimized adsorption of OOH*,thus leading to high effi ciency and durability in electrocatalytic H_(2)O_(2) production.

关键词： Oxygen reduction reaction n-doped carbon Reaction path Structural evolution Oxidation in reduction

n-doped carbon-embedded Tin nanowires as a multifunctional separator for Li–S batteries with enhanced rate capability and cycle stability

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Journal of Energy Chemistry 2021年第6期30卷 10-18,I0001页

作者： Yoongon Kim Yuseong noh Jaejin Bae Hyunwoo Ahn Minho Kim Won Bae Kim Department of Chemical Engineering Pohang University of Science and Technology(POSTECH)77 Cheongam-roNam-guPohang 37673South Korea

Lithium-sulfur(Li-S)batteries have attracted considerable attention as next-generation energy storage devices owing to their high theoretical specific capacity and ***,the commercialization of Li-S batteries is hindered by critical issues,including the migration of the dissolved lithium polysulfides(LiPSs)from the sulfur electrode to the lithium metal anode,resulting in poor cycling ***,we report a multifunctional interlayer configured with an n-doped carbon framework and titanium nitride nanowires on a polypropylene separator(nC/Tin nWs@PP)to suppress the polysulfide shuttling ***/Tin nWs@PP can be obtained by electrospinning and the subsequent scalable solution-based vacuum *** one-dimensional structure of the Tin nWs can shorten the Li-ion diffusion distance with large electrode/electrolyte ***,the n-doped carbon framework in the nWs enables facile electron transportation and allows the suppression of the shuttle effect to improve the electrochemical reaction *** Li-S battery with a nC/Tin nWs@PP separator exhibited enhanced cycling stability and rate capability,indicating that this could be a new research direction for Li-S batteries.

关键词： Li-S battery Shuttle effect Interlayer Separator Tin n-doped carbon 1D nanowire

n-doped carbon-stabilized PtCo nanoparticles derived from Pt@ZIF-67： Highly active and durable catalysts for oxygen reduction reaction

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nano Research 2017年第9期10卷 3228-3237页

作者： nana Du Chengming Wang Ran Long Yujie Xiong Hefei national Laboratory for Physical Sciences at the Microscale iChEM (Collaborative Innovation Center of Chemistry for Energy Materials) School of Chemistry and Materials Science and National Synchrotron Radiation Laboratory University of Science and Technology of China Hefei 230026 China School of Chemistry and Materials Engineering Fuyang Normal College Fuyang 236041 China

The development of catalysts with high activity and durability for the cathodic oxygen reduction reaction (ORR) in both alkaline and acidic media is important for improving the performance of the proton exchange membrane (PEM) fuel cells. This can be achieved by dispersing Pt-based alloy nanoparticles inside n-doped porous carbon frameworks. However, it still requires the development of a facile method towards synthesizing this unique hybrid structure. In this work, we demonstrate that n-doped carbon-stabilized PtCo nanoparticles (PtCo@nC) can be facilely synthesized via thermal decomposition of Pt-incorporated Co-based zeolitic imidazolate framework (Pt@ZIF-67). The thickness of the carbon framework can be optimized to enable excellent durability, in sharp contrast to a commercial Pt/C catalyst. The mass activities achieved by optimizing the thickness of the carbon framework are 0.80 and 0.82 A·mgPt –1 at 0.9 V vs. RHE in alkaline and acidic electrolytes, respectively, which are nearly 8 times greater than those of the Pt/C. This work provides an alternative approach to low-cost and high-performance catalysts for both alkaline and acidic fuel cells.

关键词： oxygen reduction reaction PtCo nanoparticles ZIF-67 n-doped carbon metal organic frameworks

n-doped carbon-coated Co_3O_4 nanosheet array/carbon cloth for stable rechargeable Zn-air batteries

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Science China Materials 2019年第5期62卷 624-632页

作者： Qi Liu Lei Wang Xu Liu Peng Yu Chungui Tian Honggang Fu Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education of the People's Republic of China Heilongjiang University

Although the application of various nonprecious compounds as the air cathodes of Zn-air batteries has been explored, the construction of highly efficient selfsupported Co-based electrodes remains challenging and highly desired given their outstanding electrocatalytic activity and cost-effectiveness. Herein, we fabricated a three-dimensional(3D) self-supported electrode based on n-doped,carbon-coated Co3O4 nanosheets grown on a carbon cloth(i.e., nC-Co3O4/CC) through the electrochemical deposition and carbonization. When used as a binder-free electrode for oxygen evolution reaction(OER), the nC–Co3O4/CC electrode demonstrated excellent electrocatalytic activity with an overpotential of 210 mV at 10 mA cm^-2 and a Tafel slope of79.6 mV dec^-1. In the Zn-air battery test, the electrode delivered a small charge/discharge voltage gap(0.87 V at 10 mA cm^-2) and exhibited high durability without degradation after 93 cycles at the large current density of 25 mA cm^-*** durability of our electrode was superior to that of a commercial Pt/C+RuO2 catalyst. The excellent performance of nC–Co3O4/CC could be attributed to the presence of 3D structures that promoted electron/ion transfer. By the absence of a binder, the carbon coating improved electron conductivity and promoted electrochemical stability. Moreover, n doping could be used to adjust the C electron structure and accelerate electron transfer. The present study provides a facile and effective route for the synthesis of various self-supported electrodes that fulfill the requirements of different energy storage and conversion devices.

关键词： n-doped carbon Co3O4 nanosheet self-supported electrode oxygen evolution reaction Zn-air batteries

“H_(2)-free” demethoxylation of guaiacol in subcritical water using Pt supported on n-doped carbon catalysts:A cost-effective strategy for biomass upgrading

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Journal of Energy Chemistry 2021年第7期30卷 377-385页

作者： Laura Pastor-Pérez Wei Jin Juan J.Villora-Picó Qiang Wang M.Mercedes Pastor-Blas Antonio Sepúlveda-Escribano Tomas R.Reina Department of Chemical and Process Engineering University of SurreyGuildford GU27XHUnited Kingdom Laboratorio de Materiales Avanzados Departamento de Química Inorgánica-Instituto Universitario de Materiales de AlicanteUniversidad de AlicanteApartado 99E-03080 AlicanteSpain College of Environmental Science and Engineering Beijing Forestry UniversityBeijing 100083China

"H_(2)-free" HDO is a revolutionary route to circumvent the limitations of H_(2)-fed HDO reactors for biomass *** work demonstrates the viability of this economically appealing route when an adequate catalyst is ***,we have developed a new family of Pt catalysts supported on n-doped activated carbons for the H_(2)-free HDO process of *** n-donors have been used to tune the catalyst’s structural and electronic *** a general trend,the n-promoted samples are more selective towards oxygen-depleted *** best performing material,namely Pt/PAnI-AC reached outstanding guaiacol conversion values-ca.75% at 300℃ while displaying reasonable stability for multiple recycling *** advanced performance is ascribed to the modified electronic and acid-base properties which favor guaiacol activation and C-O cleavage,as well as the excellent dispersion of the Pt nano particles.

关键词： Biomass upgrading n-doped carbon Pt HDO Guaiacol H_(2)-free

Highly n-doped carbon with low graphitic-n content as anode material for enhanced initial Coulombic efficiency of lithium-ion batteries

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carbon Energy 2023年第2期5卷 236-249页

作者： Yihua Tang Jingjing Chen Zhiyong Mao Christina Roth Dajian Wang Department of Electrochemical Process Engineering Universitat BayreuthBayreuthGermany Chair of Electrochemical Process Engineering Bavarian Center for Battery Technology(BayBatt)BayreuthGermany Tianjin Key Laboratory for Photoelectric Materials and Devices School of Materials Science and EngineeringTianjin University of TechnologyTianjinPR China

n-doped carbons as one of the most prominent anode materials to replace standard graphite exhibit outstanding Li+storage ***,n-doped carbon anodes still suffer from low n-doping levels and low initial Coulombic efficiency(ICE).In this study,high n-doped and low graphitic-n carbons(LGnCs)with enhanced ICE were synthesized by taking advantage of a denitrification strategy for graphitic carbon nitride(g-C_(3)n_(4)).In brief,more than 14.5 at%of n from g-C_(3)n_(4)(55.1 at%n)was retained by reacting graphitic-n with lithium,which was subsequently *** graphitic-n is largely responsible for the irreversible capacity,the anode's performance was significantly *** to general n-doped carbons with high graphitic-n proportion(>50%)and low n content(nCs delivered a low proportion of 10.8%-17.2% within the high n-doping content of 14.5-42.7 at%,leading to an enhanced specific capacity of 1499.9mAh g^(-1) at an ICE of 93.7% for the optimal sample of LGnC(4:1).This study provides a facile strategy to control the n content and speciation,achieving both high Li+storage capacity and high ICE,and thus promoting research and application of n-doped carbon materials.

关键词： denitrification graphitic carbon nitride graphitic-n lithium-ion batteries n-doped carbon

Pseudocapacitance boosted n-doped carbon coated Fe7S8 nanoaggregates as promising anode materials for lithium and sodium storage

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nano Research 2020年第3期13卷 691-700页

作者： Yanli Zhou Ming Zhang Qi Wang Jian Yang Xingyun Luo Yanlu Li Rong Du Xinsheng Yan Xueqin Sun Caifu Dong Xiaoyu Zhang Fuyi Jiang School of Environmental and Material Engineering Yantai University Yantai 264005China Key Laboratory of Colloid and Interface Chemistry Ministry of Education School of Chemistry and Chemical EngineeringShandong UniversityJinan 250100China Institute cf Crystal Materials and State Key Laboratory of Crystal Materials Shandong UniversityJinan 250100China

Herein,the core-shell structured n-doped carbon coated Fe7S8 nano-aggregates(Fe7S8@nC)were controllably prepared via a simple three-step synthesis *** appropriate thickness of n-doped carbon layer outside Fe7S8 nano-aggregates can not only inhibit the particle pulverization induced by the big volume changes of Fe7S8,but can increase the electron transfer *** hierarchical Fe7S8 nano-aggregates composed of some primary nanoparticles can accelerate the lithium or sodium diffusion *** anode materials for Li-ion batteries(LIBs),the well-designed Fe7S8@nC nanocomposites exhibit outstanding lithium storage performance,which is better than that of pure Fe7S8,Fe3O4@nC and Fe7S8@*** these nanocomposites,the n-doped carbon coated Fe7S8 with carbon content of 26.87 wt.%shows a high reversible specific capacity of 833 mAh·g^−1 after 1,000 cycles at a high current density of 2 A·g^−*** above electrode also shows excellent high rate sodium storage *** experimental and theoretical analyses indicate that the outstanding electrochemical performance could be attributed to the synergistic effect of hierarchical Fe7S8 nanostructure and conductive n-doped carbon *** quantitative kinetic analysis indicates that the charge storage of Fe7S8@nC electrode is a combination of diffusion-controlled battery behavior and surface-induced capacitance behavior.

关键词： FeyS8 n-doped carbon anode materials Li-ion batteries na-ion batteries

Single-atomic-site iron on n-doped carbon for chemoselective reduction of nitroarenes

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nano Research 2022年第1期15卷 603-611页

作者： Guoping Lu Kangkang Sun Yamei Lin Qixuan Du Jiawei Zhang Kui Wang Pengcheng Wang School of Chemical Engineering Nanjing University of Science&TechnologyNanjing 210094China Institute of Chemical Industry of Forest Products Chinese Academy of ForestryNational Engineering Laboratory for Biomass Chemical UtilizationNanjing 210042China School of Food Science and Pharmaceutical Engineering Nanjing Normal UniversityNanjing 210032China College of Materials Science and Engineering Hunan UniversityChangsha 410082China

A facile,gram-scale and sustainable approach has been established for the synthesis of single-atomic-site iron on n-doped carbon(Fe_(SA)@nC-20A)via the pyrolysis of aniline modified FeZn-ZIFs,in which the synthesis of zeolitic imidazolate frameworks(ZIFs)can be accomplished in water at room temperature,and no acid etching is *** as-synthesized catalyst exhibits better performance on the chemoselective hydrogenation of nitroarenes with a broad substrate scope(turnover frequency(TOF)up to 1,727 h^(-1),23 examples)than most of previously reported *** on high-angle annular dark field scanning transmission microscopy(HAADF-STEM)images in combination with X-ray photoelectron spectroscopy(XPS),X-ray absorption spectroscopy(XAS),electron spin resonance(ESR),and Mossbauer spectroscopy,Fe is dispersed as single atoms via forming Fenx(x=4-6).This work not only determines the active sites of FesA@nC-20A for hydrogenation(Fen4),but also proposes tentative pathways for both n-H activation of hydrazine and the reduction of nitroarene on Fen4 site,both of which are the key steps for the hydrogenation of *** addition,this catalyst shows excellent stability,and no significant activity degradation is observed when recycling for 10 times or restoring in air for 2 months.

关键词： single-atom-site iron zeolitic imidazolate framework the hydrogenation of nitroarene n-doped carbon drug synthesis