检索结果-南通市图书馆

Enhanced Ionic Accessibility of Flexible MXene Electrodes Produced by Natural Sedimentation

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2020年第7期12卷 145-155页

作者： Ning Sun Zhaoruxin Guan qizhen zhu Babak Anasori Yury Gogotsi Bin Xu State Key Laboratory of Organic-Inorganic Composites Beijing Key Laboratory of Electrochemical Process and Technology for MaterialsBeijing University of Chemical TechnologyBeijing 100029People’s Republic of China Department of Materials Science and Engineering and A.J.Drexel Nanomaterials Institute Drexel UniversityPhiladelphiaPA 19104USA Department of Mechanical and Energy Engineering Integrated Nanosystems Development InstitutePurdue School of Engineering and TechnologyIndiana University-Purdue University IndianapolisIndianapolisIN 46202USA

MXene nanosheets have been used for preparing highly flexible integrated electrodes due to their two-dimensional(2D)morphology,flexibility,high conductivity,and abundant functional groups.However,restacking of 2D nanosheets inhibits the ion transport in MXene electrodes,limiting their thickness,rate performance,and energy storage capacity.Here,we employed a natural sedimentation method instead of the conventional vacuum-assisted filtration to prepare flexible Ti3C2TxMXene films with enlarged interlayer spacing,which facilitates the access of the lithium ions to the interlayers and thus leads to a greatly enhanced electrochemical performance.The naturally sedimented flexible film shows a double lithium storage capacity compared to the conventional vacuum-filtered MXene film,along with improved rate performance and excellent cycle stability.

关键词： MXene Natural sedimentation Vacuum filtration Interlayer spacing Li-storage

Electrostatic Self-assembly of 0D–2D SnO_(2) Quantum Dots/Ti_(3)C_(2)T_(x) MXene Hybrids as Anode for Lithium-Ion Batteries

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2019年第4期11卷 161-172页

作者： Huan Liu Xin Zhang Yifan zhu Bin Cao qizhen zhu Peng Zhang Bin Xu Feng Wu Renjie Chen School of Materials Science and Engineering Beijing Key Laboratory of Environmental Science and EngineeringBeijing Institute of TechnologyBeijing 100081People’s Republic of China State Key Laboratory of Organic-Inorganic Composites Beijing Key Laboratory of Electrochemical Process and Technology for MaterialsBeijing University of Chemical TechnologyBeijing 100029People’s Republic of China

MXenes,a new family of two-dimensional(2D)materials with excellent electronic conductivity and hydrophilicity,have shown distinctive advantages as a highly conductive matrix material for lithium-ion battery anodes.Herein,a facile electrostatic self-assembly of SnO2 quantum dots(QDs)on Ti3C2Tx MXene sheets is proposed.The as-prepared SnO2/MXene hybrids have a unique 0D-2D structure,in which the 0D SnO2 QDs(~4.7 nm)are uniformly distributed over 2D Ti3C2Tx MXene sheets with controllable loading amount.The SnO2 QDs serve as a high capacity provider and the“spacer”to prevent the MXene sheets from restacking;the highly conductive Ti3C2Tx MXene can not only provide efficient pathways for fast transport of electrons and Li ions,but also buffer the volume change of SnO2 during lithiation/delithiation by confining SnO2 QDs between the MXene nanosheets.Therefore,the 0D-2D SnO2 QDs/MXene hybrids deliver superior lithium storage properties with high capacity(887.4 mAh g?1 at 50 mA g?1),stable cycle performance(659.8 mAh g?1 at 100 mA g?1 after 100 cycles with a capacity retention of 91%)and excellent rate performance(364 mAh g?1 at 3 A g?1),making it a promising anode material for lithium-ion batteries.

关键词： MXene SnO_(2) Quantum dots 0D-2D hybrid Lithium-ion battery

Plate-to-Layer Bi2MoO6/MXene-Heterostructured Anode for Lithium-Ion Batteries

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2019年第4期11卷 439-452页

作者： Peng Zhang Danjun Wang qizhen zhu Ning Sun Feng Fu Bin Xu State Key Laboratory of Organic-Inorganic Composites Beijing Key Laboratory of Electrochemical Process and Technology for MaterialsBeijing University of Chemical TechnologyBeijing 100029People’s Republic of China Shaanxi Key Laboratory of Chemical Reaction Engineering School of Chemistry and Chemical EngineeringYan’an UniversityYan’an 716000People’s Republic of China

Bi2MoO6 is a potentially promising anode material for lithiumion batteries(LIBs)on account of its high theoretical capacity coupled with low desertion potential.Due to low conductivity and large volume expansion/contraction during charge/discharge cycling of Bi2MoO6,effective modification is indispensable to address these issues.In this study,a plate-to-layer Bi2MoO6/Ti3C2Tx(MXene)heterostructure is proposed by electrostatic assembling positive-charged Bi2MoO6 nanoplates on negative-charged MXene nanosheets.MXene nanosheets in the heterostructure act as a highly conductive substrate to load and anchor the Bi2MoO6 nanoplates,so as to improve electronic conductivity and structural stability.When the mass ratio of MXene is optimized to 30%,the Bi2MoO6/MXene heterostructure exhibits high specific capacities of 692 mAh g?1 at 100 mA g?1 after 200 cycles and 545.1 mAh g?1 with 99.6%coulombic efficiency at 1 A g?1 after 1000 cycles.The results provide not only a highperformance lithium storage material,but also an effective strategy that could address the intrinsic issues of various transition metal oxides by anchoring them on MXene nanosheets to form heterostructures and use as anode materials for LIBs.

关键词： Bi2MoO6 MXene Electrostatic self-assembly Heterostructure Lithium-ion batteries

Self-propagating fabrication of 3D porous MXene-rGO film electrode for high-performance supercapacitors

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2021年第1期30卷 243-250,I0008页

作者： Jiawei Miao qizhen zhu Kangle Li Peng Zhang Qian Zhao Bin Xu State Key Laboratory of Organic-Inorganic Composites Beijing Key Laboratory of Electrochemical Process and Technology for MaterialsBeijing University of Chemical TechnologyBeijing 100029China State Key Laboratory of Biobased Material and Green Papermaking Qilu University of TechnologyShandong Academy of SciencesJinan 250353ShandongChina

2D MXene nanosheets with metallic conductivity and high pseudo-capacitance are promising electrode materials for supercapacitors.Especially,MXene films can be directly used as electrodes for flexible supercapacitors.However,they suffer from sluggish ion transport due to self-restacking,causing limited electrochemical performance.Herein,a flexible 3D porous MXene film is fabricated by incorporating graphene oxide(GO) into MXene film followed by self-propagating reduction.The self-propagating process is facile and effective,which can be accomplished in 1.25 s and result in 3D porous framework by releasing substantial gas instantaneously.As the 3D porous structure provides massive ion-accessible active sites and promotes fast ion transport,the MXene-rGO films exhibit superior capacitance and rate performance.With the rGO content of 20%,the MXene-rGO-20 film delivers a high capacitance of 329.9 F g^(-1) at 5 mV s^(-1) in 3 M H2 SO4 electrolyte and remains 260.1 F g^(-1) at 1,000 mV s^(-1) as well as good flexibility.Furthermore,the initial capacitance is retained above 90% after 40,000 cycles at 100 A g^(-1),revealing good cycle stability.This work not only provides a high-performance flexible electrode for supercapacitors,but also proposes an efficient and time-saving strategy for constructing 3D structure from 2D materials.

关键词： Porous MXene Self-propagating Graphene Supercapacitors Rate performance

A mini-review on MXenes as versatile substrate for advanced sensors

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2020年第4期31卷 922-930页

作者： Razium Ali Soomro Sana Jawaid qizhen zhu Zaheer Abbas Bin Xu Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing 100029China State Key Laboratory of Organic-Inorganic Composites Beijing Key Laboratory of Electrochemical Process and Technology for MaterialsBeijing University of Chemical TechnologyBeijing 100029China National Centre of Excellence in Analytical Chemistry University of SindhJamshoro 76080Pakistan

MXenes have emerged as versatile 2D materials that are already gaining paramount attention in the areas of energy,catalyst,electromagnetic shielding,and sensors.The unique surface chemistry,graphene-like mo rphology,high hydrophilicity,metal-like conductivity with redox capability identifies MXenes,as an ideal material for surface-related applications.This short review summarizes the most recent reports that discuss the potential application of MXenes and their hybrids as a transducer material for advanced sensors.Based on the nature of transducing signals,the discussion is categorized into three sections,which include electrochemical(bio)sensors,gas sensors,and finally,electro-chemiluminescence&fluorescent sensors.The review provides a concise summary of all the analytical merits obtained subsequent to the use of MXenes,followed by endeavors that have been made to accentuate the future perspective of MXenes in sensor devices.

关键词： MXenes Electrochemical sensors Gas sensors Electrochemiluminescent sensor Fluorescent sensors

MOF-Derived ZnS Nanodots/Ti_(3)C_(2)T_(x) MXene Hybrids Boosting Superior Lithium Storage Performance

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2021年第12期13卷 247-263页

作者： Bin Cao Huan Liu Xin Zhang Peng Zhang qizhen zhu Huiling Du Lianli Wang Rupeng Zhang Bin Xu State Key Laboratory of Organic-Inorganic Composites Beijing Key Laboratory of Electrochemical Process and Technology for MaterialsBeijing University of Chemical TechnologyBeijing 100029People’s Republic of China College of Materials Science and Engineering Xi’an University of Science and TechnologyXi’an 710054People’s Republic of China

ZnS has great potentials as an anode for lithium storage because of its high theoretical capacity and resource abundance;however,the large volume expansion accompanied with structural collapse and low conductivity of ZnS cause severe capacity fading and inferior rate capability during lithium storage. Herein,0D-2 D ZnS nanodots/Ti_(3)C_(2)T_x MXene hybrids are prepared by anchoring ZnS nanodots on Ti_(3)C_(2)T_(x) MXene nanosheets through coordination modulation between MXene and MOF precursor(ZIF-8) followed with sulfidation. The MXene substratecoupled with the ZnS nanodots can synergistically accommodate volume variation of ZnS over charge–discharge to realize stable cyclability. As revealed by XPS characterizations and DFT calculations,the strong interfacial interaction between ZnS nanodots and MXene nanosheets can boost fast electron/lithium-ion transfer to achieve excellent electrochemical activity and kinetics for lithium storage. Thereby,the as-prepared ZnS nanodots/MXene hybrid exhibits a high capacity of 726.8 mAh g^(-1) at 30 mA g^(-1),superior cyclic stability(462.8 mAh g^(-1) after 1000 cycles at 0.5 A g^(-1)),and excellent rate performance. The present results provide new insights into the understanding of the lithium storage mechanism of ZnS and the revealing of the e ects of interfacial interaction on lithium storage performance enhancement.

关键词： Ti_(3)C_(2)T_(x)MXene MOF Interfacial interaction Heterointerface ZnS Lithium-ion batteries

Facile synthesis of rutile TiO2/carbon nanosheet composite from MAX phase for lithium storage

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2019年第9期35卷 1977-1981页

作者： Zhaoruxin Guan Xiaoxue Wang Tingting Li qizhen zhu Mengqiu Jia Bin Xu State Key Laboratory of Organic-Inorganic Composites Beijing Key Laboratory of Electrochemical Process and Technology for Materials Beijing University of Chemical Technology

Titanium oxide(TiO2),with excellent cycling stability and low volume expansion,is a promising anode material for lithium-ion battery(LIB),which suffers from low electrical conductivity and poor rate capability.Combining nano-sized TiO2 with conductive materials is proved an efficient method to improve its electrochemical properties.Here,rutile TiO2/carbon nanosheet was obtained by calcinating MAX(Ti3AlC2)and Na2C03 together and water-bathing with HC1.The lamellar carbon atoms in MAX are converted to 2D carbon nanosheets with urchin-like rutile TiO2 anchored on.The unique architecture can offer plentiful active sites,shorten the ion diffusion distance and improve the conductivity.The composite exhibits a high reversible capacity of 247 mA h g^-1,excellent rate performance(38 mA h g^-1 at 50 C)and stable cycling performance(0.014%decay per cycle during 2000 cycles)for lithium storage.

关键词： TiO2/C Composite Anode Lithium ion battery MAX

3D crumbled MXene for high-performance supercapacitors

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2020年第9期31卷 2305-2308页

作者： Xin Zhang Jiawei Miao Peng Zhang qizhen zhu Mingchi Jiang Bin Xu State Key Laboratory of Organic–Inorganic Composites Beijing Key Laboratory of Electrochemical Process and Technology for MaterialsBeijing University of Chemical TechnologyBeijing 100029China

MXene materials have recently attracted considerable attention in energy storage application owing to their metallic conductivity,2D structure and tunable surface terminations.However,the restacking of 2D MXene nanosheets hinders the ion transport and accessibility to the surface,resulting in adverse effect on their electrochemical performances.Here,with the assistance of hexamethylenetetramine(C6H12N4),2DTi3C2Tx MXene nanosheets were fabricated into a 3D architecture with crumbled and porous structure through an electrostatic self-assembly followed by annealing.The resultant 3D structure can expose massive active sites and facilitates the ion transport,which is beneficial for sufficient utilization of the outstanding superiorities of the MXene.Therefore,as a pseudocapacitive material,the 3D crumpled and porous Ti3C2Tx MXene shows a gravimetric capacitance of 333 F/g at 1 A/g,and maintains 261 F/g and 132 F/g at ultrahigh current densities of 100 A/g and 1000 A/g,respectively,revealing promising potential for application in supercapacitors.

关键词： Supercapacitors MXene nanosheets 3D porous structure Capacitance Rate performance

在线全文

学校读者我要写书评

暂无评论

窨制方式对玫瑰红茶品质的影响

中国食品学报 2024年第4期24卷 266-277页

作者：孟鑫朱艳汪芳杜琪珍尹军峰许勇泉浙江农林大学食品与健康学院杭州311300 中国农业科学院茶叶研究所杭州310008

传统花茶的窨制主要是以鲜花与茶叶结合,为探究不同的窨制方法对玫瑰红茶的滋味和品质的影响,通过4种窨制方法(鲜花赋香、玫瑰细胞液喷洒赋香、玫瑰细胞液蒸气赋香、花瓣与细胞液蒸气结合赋香)对红茶进行赋香,完成玫瑰红茶的窨制。以色... 详细信息

传统花茶的窨制主要是以鲜花与茶叶结合,为探究不同的窨制方法对玫瑰红茶的滋味和品质的影响,通过4种窨制方法(鲜花赋香、玫瑰细胞液喷洒赋香、玫瑰细胞液蒸气赋香、花瓣与细胞液蒸气结合赋香)对红茶进行赋香,完成玫瑰红茶的窨制。以色差、茶多酚总量、游离氨基酸含量、儿茶素等指标为依据,结合HS-SPME-GC-MS对不同窨制工艺制得的玫瑰红茶香气成分进行分析。结果表明,4种赋香方式所得玫瑰红茶的理化成分具有显著性差异(P<0.05)。用鲜花赋香和细胞液喷洒赋香的两种红茶茶汤偏红、偏黄,明亮度不及其它2种赋香方式。以喷洒玫瑰细胞液的窨制方式得到的玫瑰红茶氨基酸含量较高(112.66 mg/L);以玫瑰鲜花窨制得到的玫瑰红茶茶多酚含量较低(680.38 mg/L)。玫瑰红茶的主要呈香化合物为苯乙醛、芳樟醇、(E,E)-2,4-庚二烯醛、水杨酸甲酯、乙酸苯乙酯、β-紫罗酮、香叶醇、2-正戊基呋喃和正己醛这9种,玫瑰鲜花细胞液窨制的玫瑰红茶中含有的9种主要呈香化合物显著高于其它3种。本研究有助于创新玫瑰红茶的窨制方式,为高品质玫瑰红茶的窨制提供参考。

关键词：玫瑰红茶赋香玫瑰花细胞液