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Intercalation of multiply solvated hexafluorophospate anion into graphite electrode from mixtures of methyl acetate,ethyl methyl and ethylene carbonates 被引量:2
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作者 Lei Zhang Hongyu Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第7期233-236,共4页
Graphite is a universal host material for ion intercalation. Li+-graphite intercalation compounds (GICs) have been successfully utilized as the anode material in commercial lithium-ion batteries.Similarly, anion-graph... Graphite is a universal host material for ion intercalation. Li+-graphite intercalation compounds (GICs) have been successfully utilized as the anode material in commercial lithium-ion batteries.Similarly, anion-graphite intercalation compounds (AGICs) have been coming into their own in dual-ion batteries [1]. It is imperative to deepen an understanding of anion storage mechanisms in graphite electrode. 展开更多
关键词 Multiply solvated anions Anion-graphite intercalation compounds Methyl acetate Ethylene carbonate Ethyl methyl carbonate
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Design strategy and comprehensive performance assessment towards Zn anode for alkaline rechargeable batteries
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作者 Di Yang Jinsheng Li +2 位作者 Changpeng Liu Wei Xing Jianbing Zhu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第7期122-138,I0004,共18页
Alkaline Zn-based primary batteries have been commercialized in the past decades.However,their success has not been extended to secondary batteries due to the poor cycle reversibility of Zn anodes.Although some resear... Alkaline Zn-based primary batteries have been commercialized in the past decades.However,their success has not been extended to secondary batteries due to the poor cycle reversibility of Zn anodes.Although some research has been conducted on alkaline Zn anodes,their performance is still far from commercial requirements.A variety of degradation mechanisms,including passivation,dendrites,morphological changes,and hydrogen precipitation,are claimed responsible for the failure of alkaline Zn metal anodes.What’s worse,these constraints always interact with each other,which leads to a single strategy being unable to suppress all the issues.Therefore,a comprehensive evaluation of the positive and negative effects of various strategies on performance is important to promote the commercialization of alkaline Zn batteries.Herein,the recent progress and performance of improvement strategies for Zn anode in alkaline conditions are reviewed systematically.First,the principles and challenges of alkaline Zn anodes are briefly analyzed.Then,various design strategies for alkaline Zn anodes from the perspectives of ion and electron regulation are highlighted.Last,through a comprehensive summary of various performance parameters,the advantages and disadvantages of different strategies are compared and evaluated.On the basis of this assessment,we aim to provide more insights into the anode design of high-performance alkaline rechargeable Zn batteries. 展开更多
关键词 Alkaline aqueous batteries Zinc anode Regulation strategies Performance assessment
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The decisive role of adsorbed OH^(*)in low‐potential CO electro‐oxidation on single‐atom catalytic sites
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作者 Yang Li Xian Wang +7 位作者 Ying Wang Zhaoping Shi Yuqi Yang Tuo Zhao Zheng Jiang Changpeng Liu Wei Xing Junjie Ge 《Carbon Energy》 SCIE EI CAS CSCD 2023年第9期63-73,共11页
CO impurity-induced catalyst deactivation has long been one of the biggest challenges in proton-exchange membrane fuel cells,with the poisoning phenomenon mainly attributed to the overly strong adsorption on the catal... CO impurity-induced catalyst deactivation has long been one of the biggest challenges in proton-exchange membrane fuel cells,with the poisoning phenomenon mainly attributed to the overly strong adsorption on the catalytic site.Here,we present a mechanistic study that overturns this understanding by using Rh-based single-atom catalysis centers as model catalysts.We precisely modulated the chelation structure of the Rh catalyst by coordinating Rh with C or N atoms,and probed the reaction mechanism by surface-enhanced Raman spectroscopy.Direct spectroscopic evidence for intermediates indicates that the reactivity of adsorbed OH^(*),rather than the adsorption strength of CO^(*),dictates the CO electrocatalytic oxidation behavior.The RhN_(4)sites,which adsorb the OH^(*)intermediate more weakly than RhC4 sites,showed prominent CO oxidation activity that not only far exceeded the traditional Pt/C but also the RhC4 sites with similar CO adsorption strength.From this study,it is clear that a paradigm shift in future research should be considered to rationally design high-performance CO electro-oxidation reaction catalysts by sufficiently considering the water-related reaction intermediate during catalysis. 展开更多
关键词 adsorbed CO^(*)and OH^(*) carbon‐based Rh single‐atom catalysts CO electro‐oxidation reaction electron interaction MNx moiety
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Preparation of Chemically Recyclable Poly(ether-alt-ester) by the Ring Opening Polymerization of Cyclic Monomers Synthesized by Coupling Glycolide and Epoxides
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作者 Feng Ren Zhuang-Zhuang Liang +2 位作者 Ming-Xin Niu Chen-Yang Hu Xuan Pang 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2024年第2期168-175,I0006,共9页
Polyester and polyether are two key oxygenated polymers, and completely alternative sequence of poly(ester-alt-ether) could efficiently combine the advantages(including flexibility, degradability, etc.) of both segmen... Polyester and polyether are two key oxygenated polymers, and completely alternative sequence of poly(ester-alt-ether) could efficiently combine the advantages(including flexibility, degradability, etc.) of both segments. Currently, despite their copolymers could be synthesized from one-pot mixture of cyclic esters and epoxides, perfectly alternative microstructure is very challenging to realize and typically restricted to certain monomer pairs. Moving forward, synthesizing poly(ester-alt-ether) from commercially available and largescale monomers would be a significant advance. For example, successfully commercialized poly(glycolic acid)(PGA), which is not easily soluble in polymers due to its high crystallinity and is brittle and difficult to control the degradation cycle, would encounter a new paradigm if engineered into poly(ester-altether). In this work, starting from the design of monomer with hybrid structures, we successfully synthesized a series of 1,4-dioxan-2-one containing different substituents based on glycolide(GA) and epoxides using commercially available Salen-Cr(III) and PPNCl catalytic systems.The new monomers underwent ring-opening polymerization(ROP) to form a series of poly(ester-alt-ether) with perfectly alternating glycolic acid and propylene glycol repeat units under catalytic system of thiourea/base. The poly(ester-alt-ether) have significantly lower glass-transition temperature than PGA. Additionally, the poly(ester-alt-ether) can be chemically recovered to monomer using Sn(Oct)2 or 1,8-diazabicyclo[5.4.0]undecane-7-ene(DBU) as a catalyst in solution, thus establishing a closed-loop life cycle. From monomers derived from GA and epoxides, this work furnishes a novel strategy for the synthesis of poly(ester-alt-ether) with chemical recyclability. 展开更多
关键词 Polyester POLYETHER Alternative copolymer Ring-opening polymerization
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Regio-and Stereoselective Polymerization of Bio-based Ocimene by Rare-Earth Metal Catalysts
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作者 Qi-Yuan Wang Li-Peng Sang +5 位作者 Zhen Zhang Yang Jiang Hui Tian Xia Zhao Xiang Guo Shi-Hui Li 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2024年第2期223-229,I0008,共8页
Coordination polymerization of renewable β-ocimene has been investigated using asymmetric diiminophosphinate lutetium complex1, β-diketiminate yttrium complex 2, bis(phosphino)carbazolide yttrium complex 3, half-san... Coordination polymerization of renewable β-ocimene has been investigated using asymmetric diiminophosphinate lutetium complex1, β-diketiminate yttrium complex 2, bis(phosphino)carbazolide yttrium complex 3, half-sandwich benzyl fluorenyl scandium complex 4 and pyridyl-methylene-fluorenyl rare-metal complexes 5a–5c. Complexes 1, 4 and 5a–5c show trans-1,2-regioselectivities and high activities, of which 5c exhibits excellent isoselectivity(mmmm>99%). Conversely, complexes 2 and 3 promote β-ocimene polymerization to produce isotactic cis-1,4-polyocimenes(cis-1,4>99%, mm>95%). Diblock copolymers cis-1,4-PIP-block-cis-1,4-POc and cis-1,4-PBD-block-cis-1,4-POc are obtained in one-pot reactions of β-ocimene with isoprene and butadiene using complex 3. Epoxidation and hydroxylation of polyocimene afford functionalized polyolefins with enhanced T_(g)(from-20 ℃ to 79 ℃ and 74 ℃) and hydrophilicity. 展开更多
关键词 Biobased monomer TERPENES OCIMENE RARE-EARTHS Polymerization Regio/stereoselectivity Elastomer
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Atomic-level coupled RuO_(2)/BaRuO_(3) heterostructure for efficient alkaline hydrogen evolution reaction
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作者 Yueying Yan Tian Meng +4 位作者 Yuting Chen Yang Yang Dewen Wang Zhicai Xing Xiurong Yang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期356-362,I0009,共8页
The slow water dissociation is the rate-determining step that slows down the reaction rate in alkaline hydrogen evolution reaction(HER).Optimizing the surface electronic structure of the catalyst to lower the energy b... The slow water dissociation is the rate-determining step that slows down the reaction rate in alkaline hydrogen evolution reaction(HER).Optimizing the surface electronic structure of the catalyst to lower the energy barrier of water dissociation and regulating the binding strength of adsorption intermediates are crucial strategy for boosting the catalytic performance of HER.In this study,RuO_(2)/BaRuO_(3)(RBRO)heterostructures with abundant oxygen vacancies and lattice distortion were in-situ constructed under a low temperature via the thermal decomposition of gel-precursor.The RBRO heterostructures obtained at 550℃ exhibited the highest HER activity in 1 M KOH,showing an ultra-low overpotential of 16 mV at 10 mA cm^(-2)and a Tafel slope of 33.37 m V dec^(-1).Additionally,the material demonstrated remarkable durability,with only 25 mV of degradation in overpotential after 200 h of stability testing at 10 mA cm^(-2).Density functional theory calculations revealed that the redistribution of charges at the heterojunction interface can optimize the binding energies of H*and OH*and effectively lower the energy barrier of water dissociation.This research offers novel perspectives on surpassing the water dissociation threshold of alkaline HER catalysts by means of a systematic design of heterogeneous interfaces. 展开更多
关键词 HETEROSTRUCTURE Hydrogen evolution reaction Interfacial electron transfer Oxygen vacancies
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Facile Synthesis of Polyisothioureas via Alternating Copolymerization of Aziridines and Isothiocayanates
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作者 Hao-Tian Zhang Ming-Xin Niu +2 位作者 Qi Zhang Chen-Yang Hu Xuan Pang 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2024年第3期292-298,I0005,共8页
Isothiourea is an important class of sulfur-containing molecules showing unique catalytic and biological activities. As such,polyisothiourea is envisioned to be an interesting type of polymer that potentially exhibits... Isothiourea is an important class of sulfur-containing molecules showing unique catalytic and biological activities. As such,polyisothiourea is envisioned to be an interesting type of polymer that potentially exhibits a number of interesting properties. However, there is no access to synthesizing well-defined polyisothiourea, and currently isothiourea-containing polymers are mainly prepared by immobilizing onto other polymer's side chain. Herein, we report the first facile synthesis of polyisothioureas via alternating copolymerization of aziridines and isothiocayanates. Mediated by the catalytic system of phosphazene superbases/alcohol, a broad scope of aziridines and isothiocayanates could be transformed into polyisothioureas with adjustable substitutions(11 examples). The structures of obtained polyisothioureas were fully characterized with ^(1)H-NMR, ^(13)C-NMR, and ^(1)H-^(13)C HMBC NMR. Moreover, the polyisothioureas show tunable thermal properties depending on substitutions on the isothiourea linkages. The novel structure of these polyisothioureas will enable a powerful platform for the discovery of nextgeneration functional plastics. 展开更多
关键词 Polyisothioureas Alternative copolymer AZIRIDINES Isothiocayanates
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Atomically dispersed Fe sites on hierarchically porous carbon nanoplates for oxygen reduction reaction
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作者 Ruixue Zheng Qinglei Meng +9 位作者 Hao Zhang Teng Li Di Yang Li Zhang Xiaolong Jia Changpeng Liu Jianbing Zhu Xiaozheng Duan Meiling Xiao Wei Xing 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第3期7-15,I0002,共10页
Developing cost-effective,robust and stable non-precious metal catalysts for oxygen reduction reaction(ORR) is of paramount importance for electrochemical energy conversion devices such as fuel cells and metal-air bat... Developing cost-effective,robust and stable non-precious metal catalysts for oxygen reduction reaction(ORR) is of paramount importance for electrochemical energy conversion devices such as fuel cells and metal-air batteries.Although Fe-N-C single atom catalysts(SACs) have been hailed as the most promising candidate due to the optimal binding strength of ORR intermediates on the Fe-N_(4) sites,they suffer from serious mass transport limitations as microporous templates/substrates,i.e.,zeolitic imidazolate frameworks(ZIFs),are usually employed to host the active sites.Motivated by this challenge,we herein develop a hydrogen-bonded organic framework(HOF)-assisted pyrolysis strategy to construct hierarchical micro/mesoporous carbon nanoplates for the deposition of atomically dispersed Fe-N_(4) sites.Such a design is accomplished by employing HOF nanoplates assembled from 2-aminoterephthalic acid(NH_(2)-BDC) and p-phenylenediamine(PDA) as both soft templates and C,N precursors.Benefitting from the structural merits inherited from HOF templates,the optimized catalyst(denoted as Fe-N-C SAC-950) displays outstanding ORR activity with a high half-wave potential of 0.895 V(vs.reversible hydrogen electrode(RHE)) and a small overpotential of 356 mV at 10 mA cm^(-2) for the oxygen evolution reaction(OER).More excitingly,its application potential is further verified by delivering superb rechargeability and cycling stability with a nearly unfading charge-discharge gap of 0.72 V after 160 h.Molecular dynamics(MD) simulations reveal that micro/mesoporous structure is conducive to the rapid mass transfer of O_(2),thus enhancing the ORR performance.In situ Raman results further indicate that the conversion of O_(2) to~*O_(2)-the rate-determining step(RDS) for Fe-N-C SAC-950.This work will provide a versatile strategy to construct single atom catalysts with desirable catalytic properties. 展开更多
关键词 Fe single atom catalysts Oxygen reduction reaction Mesoporous structure Active sites Zinc-air battery
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Unlocking the potential of ultra-thin two-dimensional antimony materials:Selective growth and carbon coating for efficient potassium-ion storage
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作者 Dongyu Zhang Zhaomin Wang +4 位作者 Yabin Shen Yeguo Zou Chunli Wang Limin Wang Yong Cheng 《Journal of Energy Chemistry》 SCIE EI CAS 2024年第5期440-449,共10页
Antimony-based anodes have attracted wide attention in potassium-ion batteries due to their high theoretical specific capacities(∼660 mA h g^(-1))and suitable voltage platforms.However,severe capacity fading caused b... Antimony-based anodes have attracted wide attention in potassium-ion batteries due to their high theoretical specific capacities(∼660 mA h g^(-1))and suitable voltage platforms.However,severe capacity fading caused by huge volume change and limited ion transportation hinders their practical applications.Recently,strategies for controlling the morphologies of Sb-based materials to improve the electrochemical performances have been proposed.Among these,the two-dimensional Sb(2D-Sb)materials present excellent properties due to shorted ion immigration paths and enhanced ion diffusion.Nevertheless,the synthetic methods are usually tedious,and even the mechanism of these strategies remains elusive,especially how to obtain large-scale 2D-Sb materials.Herein,a novel strategy to synthesize 2D-Sb material using a straightforward solvothermal method without the requirement of a complex nanostructure design is provided.This method leverages the selective adsorption of aldehyde groups in furfural to induce crystal growth,while concurrently reducing and coating a nitrogen-doped carbon layer.Compared to the reported methods,it is simpler,more efficient,and conducive to the production of composite nanosheets with uniform thickness(3–4 nm).The 2D-Sb@NC nanosheet anode delivers an extremely high capacity of 504.5 mA h g^(-1) at current densities of 100 mA g^(-1) and remains stable for more than 200 cycles.Through characterizations and molecular dynamic simulations,how potassium storage kinetics between 2D Sb-based materials and bulk Sb-based materials are explored,and detailed explanations are provided.These findings offer novel insights into the development of durable 2D alloy-based anodes for next-generation potassium-ion batteries. 展开更多
关键词 Antimony Two-dimensional materials Selective growth Nitrogen-doped carbon Potassium-ion batteries
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Hierarchical intercalation of tetrafluoroborate anion into graphite electrode from sulfolane
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作者 Yunju Wang Hongyu Wang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第12期378-382,I0010,共6页
The anion storage behavior of graphite positive electrode in a dual-ion battery is closely related to the solvation of anion in the corresponding electrolyte solution.The classical electrolyte solutions of Li BF_(4)^(... The anion storage behavior of graphite positive electrode in a dual-ion battery is closely related to the solvation of anion in the corresponding electrolyte solution.The classical electrolyte solutions of Li BF_(4)^(-)sulfolane(SL)have long been recognized in the community of lithium batteries and still appear promising in dual-ion batteries.Nevertheless,the solvation of BF_(4)^(-)by SL has seldom been addressed before.In this study,the solvation states of SL-BF_(4)^(-)are adjusted by varying LiBF_(4)concentration or introducing auxiliary salts of LiPF_6or SBPBF_(4)(SBP:spiro-(1,1')-bipyrrolidinium)in the electrolyte solutions of Li/graphite dualion cells.The electrochemical storage processes of SL-BF_(4)^(-)anions in graphite electrodes are investigated through in situ X-ray diffraction measurements.Two kinds of graphite intercalation compounds(GICs)with contrastive intercalation gallery heights(IGHs)have been discovered,which are ascribed to the storage of different kinds of SL-BF_(4)^(-)anions in graphite electrode.The interactions between ions and SL in the electrolyte solutions are characterized by Fourier transform infrared spectroscopy and then correlated with the performance of Li/graphite cells. 展开更多
关键词 Dual-ion batteries Lithium tetrafluoroborate SULFOLANE In situ XRD Highly concentrated solutions
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Domain controlling and defect passivation for efficient quasi-2D perovskite LEDs
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作者 Dezhong Zhang Chuanjiang Qin Liming Ding 《Journal of Semiconductors》 EI CAS CSCD 2022年第5期1-4,共4页
Metal halide perovskites have made rapid progress in photonic and optoelectronic applications since the first report of solid-state perovskite solar cells in 2012[1].Perovskites feature superior luminescence propertie... Metal halide perovskites have made rapid progress in photonic and optoelectronic applications since the first report of solid-state perovskite solar cells in 2012[1].Perovskites feature superior luminescence properties beneficial for the application in light emitting diodes(LEDs),such as high photoluminescence quantum yields(PLQYs),narrow emission. 展开更多
关键词 OPTOELECTRONIC DIODES PEROVSKITE
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Identification of active sites and synergistic effect in multicomponent carbon-based Ru catalysts during electrocatalytic hydrogen evolution 被引量:2
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作者 Rongpeng Ma Xian Wang +4 位作者 Xiaolong Yang Yang Li Changpeng Liu Junjie Ge Wei Xing 《Nano Research》 SCIE EI CSCD 2023年第1期166-173,共8页
Single atom catalysts(SACs)were reported to demonstrate exciting catalytic features for a number of reactions,including hydrogen evolution reaction(HER).However,the true role of these single atom sites in catalysts re... Single atom catalysts(SACs)were reported to demonstrate exciting catalytic features for a number of reactions,including hydrogen evolution reaction(HER).However,the true role of these single atom sites in catalysts remains elusive,particularly for those prepared via pyrolysis,where the formation of active nanoparticle counterparts is often unavoidable.Here we report a Ru based catalyst(Ru embedded in N doped carbon spheres(Ru/NPCS))comprising of both Ru nanoclusters and Ru single sites,who demonstrates activity exceeding Pt catalyst and mass activity among the best of the Ru based catalysts under acidic conditions.The integration of proton exchange membrane water electrolysis with Ru/NPCS as a cathode exhibited an excellent hydrogen generation activity and extraordinary stability(during 120 h of electrolysis)with a 1/48 Ru loading(16.5μgRu·cm^(−2))of a commercial 20%Pt/C catalyst.Through precisely tailoring the dispersion status of the catalysts,we reveal that while ruthenium nanoclusters actively catalyze HER via Volmer–Tafel mechanism,the Ru SACs barely catalyze HER,with H*adsorption difficult to occur.Moreover,no synergy between Ru SACs and Ru cluster is revealed,meaning the Ru SACs act as a spectator rather than active species during H2 evolution. 展开更多
关键词 hydrogen evolution reaction single atom catalysts NANOCLUSTERS no synergy
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Tunable catalytic activity of FeWO_(4) nanomaterials for sensitive assays of pyrophosphate ion and alkaline phosphatase activity
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作者 Xianqing Tang Jinghuang Chen +2 位作者 Mengqian Zhang Jian Sun Xiurong Yang 《Science China Chemistry》 SCIE EI CAS CSCD 2023年第6期1860-1868,共9页
Alkaline phosphatase(ALP)activity and pyrophosphate ion(PPi)levels are remarkable for the human body functions such as signal transduction pathways and metabolism.Current quantitative methods mainly focus on developin... Alkaline phosphatase(ALP)activity and pyrophosphate ion(PPi)levels are remarkable for the human body functions such as signal transduction pathways and metabolism.Current quantitative methods mainly focus on developing complicated organic substrates or employing unstable metal ions as signal-regulated medium.Herein,we have developed a facile hydrothermal method for preparing Fe WO_(4)nanomaterials with intrinsic peroxidase-like activity and further confirmed that such a catalytic activity could be significantly enhanced by adjusting the size and oxygen vacancy content.More encouragingly,PPi can easily inhibit the catalytic activity of Fe WO_(4),whereas orthophosphate ions(Pi)cannot.Therefore,we constructed an Fe WO_(4)-based colorimetric assay for sensing PPi by means of the classical 3,3′,5,5′-tetramethylbenzidine-peroxidase chromogenic reaction.A facile and reliable ALP activity assay was also designed and developed because of the logical regulation of the peroxidase-like activity of Fe WO_(4)through the ALP-catalyzed hydrolysis of PPi into Pi.Based on the clear mechanism and mimetic-enzyme Fe WO_(4)-catalyzed amplification,the sensing system exhibited excellent performance and was able to evaluate ALP activity in real serum samples and screen for potential ALP inhibitors.The proposed mimetic enzyme-involved colorimetric assay provides an alternative pathway,and Fe WO_(4)nanomaterials with excellent performance have great potential for further biosensing and biomedical applications. 展开更多
关键词 FewO4 nanomaterials mimetic enzyme oxygen vacancy COLORIMETRY pyrophosphate ion alkaline phosphatase
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The Effect of Topologies and Refilling Short-chain PEG on Protein Adsorption
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作者 Chi Li Jia-Ning Zhang +1 位作者 Jing Jin Wei Jiang 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2023年第12期1879-1888,I0007,共11页
PEGylation is the gold standard for constructing protein resistance surfaces.Herein,grafting mPEG-SH and SH-PEG-SH with varied molecular weights(Mw=5K,10K,and 20K)on a gold chip,and the subsequent lysozyme adsorptions... PEGylation is the gold standard for constructing protein resistance surfaces.Herein,grafting mPEG-SH and SH-PEG-SH with varied molecular weights(Mw=5K,10K,and 20K)on a gold chip,and the subsequent lysozyme adsorptions of the PEG layers are evaluated using quartzcrystal microbalance based on dissipation(QCM-D).The lysozyme resistance depends on the features of grafting density and chain conformation,i.e.,linear and looped conformation.However,long-chain PEG(Mw≥10K)is insufficient to form a dense layer to resist protein due to large steric hindrances.Short-chain PEG(Mw=1K)with linear and looped structures is used to refill onto the long-chain PEG layer to increase the grafting density of PEGs and improve protein resistance.The refilling process and the subsequent protein adsorption depend on conformation rather than the density of the long-chain PEG substrate.Notably,the long-chain PEG looped substrates significantly improve protein resistance,attributing to the high viscoelasticity of the looped substrate and an increase in grafting density after refilling.Thus,refilling short-chain PEG improves protein resistance and the substrate conformation-dependence gives insight into the impact of topology,providing new ideas for how to increase chain density and select suitable topology to resist protein adsorption and demonstrating a potential application in biomedical fields. 展开更多
关键词 Poly(ethylene glycol) REFILLING Protein adsorption CONFORMATION QCM-D
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Control Aggregation of P3HT in Solution for High Efficiency Doping:Ensuring Structural Order and the Distribution of Dopants
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作者 Duo Liu Jun-Hang Li +4 位作者 Si-Chun Wang Lu Zhang Xin-Yu Liu Qiang Zhang Yan-Chun Han 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2023年第5期811-823,I0012,共14页
Molecular doping is one of the most important tools to manipulate the electrical properties of conjugated polymers for application in organic optoelectronics.The polymer crystallinity and distribution position of the ... Molecular doping is one of the most important tools to manipulate the electrical properties of conjugated polymers for application in organic optoelectronics.The polymer crystallinity and distribution position of the dopant crucially determine electrical conductivity of the doped polymer.However,in solution-mixed doping,the interplay between polymer and dopant leads to highly structural disorder of polymer and random arrangement of dopant.Here,we propose a strategy to ensure the dopant induced polarons have high charge dissociation and transport by letting the conjugated polymers aggregate in the marginal solvent solution by cooling it from higher temperature to room temperature.We select poly(3-hexylthiophene-2,5-diyl)(P3HT)solution doped by 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane(F4TCNQ)as a model system.P3HT crystallizes in the marginal solvent,such as 1,1,2-trichloroethane(TCE)driven by the favorπ-πinteraction between planar polymer backbone.The dopant F4TCNQ enters the alkyl side chain region not theπ-πstacking region and thus guarantees high crystallinity and theπ-πinteraction of P3HT.This distribution of F4TCNQ which away from the polymer backbone to ensure higher charge dissociation and transport.Finally,we obtained a high conductivity value of 23 S/cm by doping P3HT with 20%F4TCNQ by using the marginal solvent,which is higher than doping P3HT with a disordered coil conformation in chlorobenzene(CB)of 7 S/cm,which the dopants enter both the alkyl side chain region and theπ-πstacking region. 展开更多
关键词 SOLVENT CRYSTALLINE Dopant location Doping efficiency Electrical conductivity
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Chiral polypeptide nanoparticles as nanoadjuvants of nanovaccines for efficient cancer prevention and therapy
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作者 Yuanzhen Su Weiguo Xu +3 位作者 Qi Wei Yang Ma Jianxun Ding Xuesi Chen 《Science Bulletin》 SCIE EI CAS CSCD 2023年第3期284-294,M0004,共12页
The chirality of bioactive molecules is closely related to their functions.D-amino acids commonly distributed in the bacterial cell walls trigger a robust anti-infective immune response.Inspired by that,two kinds of c... The chirality of bioactive molecules is closely related to their functions.D-amino acids commonly distributed in the bacterial cell walls trigger a robust anti-infective immune response.Inspired by that,two kinds of chiral polypeptides,poly(L-phenylalanine)-block-poly(L-lysine)(PL-K)and poly(Lphenylalanine)-block-poly(D-lysine)(PD-K),were synthesized and used as nanoadjuvants of nanovaccines for cancer prevention and therapy.The amphiphilic polypeptides self-assembled into nanoparticles with a diameter of about 30 nm during ultrasonic-assisted dissolution in phosphate-buffered saline.The nanovaccines PL-K-OVA and PD-K-OVA were easily prepared by mixing solutions of PL-K or PD-K and the model antigen chicken ovalbumin(OVA),respectively,with loading efficiencies of almost 100%.Compared to PL-K-OVA,PD-K-OVA more robustly induced dendritic cell maturation,antigen cross-presentation,and adaptive immune response.More importantly,it effectively prevented and treated the OVA-expressed B16-OVA melanoma model.PD-K-OVA achieved a tumor inhibition rate of 94.9%and even 97.0%by combining with anti-PD-1 antibody.Therefore,the chiral polypeptide nanoparticles represent simple,efficient,and extensively applicable nanoadjuvants for various nanovaccines. 展开更多
关键词 Chiral polypeptide Nanoadjuvant NANOVACCINE Immunoactivation Cancer prevention and treatment
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Temperature-induced Evolution of Micro-structure and Chain Dynamics in Thermoplastic Polyurethane with Low Hard Segment Content as Studied by In Situ Synchrotron SAXS and Time-Domain NMR Experiments
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作者 Hong-Ru Wang Victor Litvinov +3 位作者 Wei Yu Kar Wee Eddie Peh Qian-Li Yu Yong-Feng Men 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2023年第12期1902-1911,I0008,共11页
The microstructural evolution of a thermoplastic polyurethane(TPU)with low hard segment content has been monitored utilizing in situ real-time synchrotron small angle X-ray scattering(SAXS)and time-domain nuclear magn... The microstructural evolution of a thermoplastic polyurethane(TPU)with low hard segment content has been monitored utilizing in situ real-time synchrotron small angle X-ray scattering(SAXS)and time-domain nuclear magnetic resonance(NMR)measurements.The TPU is composed of 23 wt% of[4,4-methylenediphenyl diisocyanate(MDI)]-[1,4-butanediol(BD)]chain segments,which form hard domains,as[polytetrahydrofuran(PTHF)]forming soft domains.The number and distribution of monomer units in hard blocks is determined by the successive self-nucleation and annealing thermal fractionation technique.In situ SAXS method reveals heating-induced increase in the spacing of hard and soft domains,while time-domain ^(1)H-NMR characterizes the changes in the phase composition and chain dynamics in these domains.A glassy fraction of short MDI-BD chain segments in hard domains passes through T_(g) above ambient temperature.At higher temperatures,MDI-BD nanocrystals start to melt.Sequence length distribution of MDI-BD chain segments causes a distribution in crystal sizes and wide melting temperature range.The melting is accompanied by the mixing of MDI-BD with PTHF segments in soft domains,and by increase in segmental mobility in these domains.Above 180℃,the TPU melt is homogeneous on the scale above nanometers according to SAXS data. 展开更多
关键词 Phase separation Thermoplastic polyurethane Melting behavior Time-domain NMR SAXS
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Highly dispersed 1 nm Pt Pd bimetallic clusters for formic acid electrooxidation through a CO-free mechanism
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作者 Zhongying Fang Ziwei Zhang +8 位作者 Shemsu Ligani Fereja Jinhan Guo Xinjie Tong Yue Zheng Rupeng Liu Xiaolong Liang Leting Zhang Zongjun Li Wei Chen 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第3期554-564,I0015,共12页
Direct formic acid fuel cell(DFAFC) is an important research project in clean energy field.However,commercialization of DFAFC is still largely limited by the available catalysts with unsatisfied activity,durability an... Direct formic acid fuel cell(DFAFC) is an important research project in clean energy field.However,commercialization of DFAFC is still largely limited by the available catalysts with unsatisfied activity,durability and cost for formic acid electrooxidation(FAEO).Using Pt-and Pd-based nanoclusters as electrocatalysts is a particularly promising strategy to solve the above problem,but two attendant problems need to be solved firstly.(Ⅰ) The controllable synthesis of practicable and stable sub-2 nm clusters remains challenging.(Ⅱ) The catalyzing mechanism of sub-2 nm metal clusters for FAEO has not yet completely understood.Herein,different from traditional solution synthesis,by designing a novel supporting material containing electron-rich and electron-deficient functional groups,size-and dispersioncontrollable synthesis of ~1 nm PtPd nanoclusters is realized by an electrochemical process.The electrocatalytic properties and reaction mechanism of the PtPd nanoclusters for the FAEO were studied by different electrochemical techniques,in-situ fourier transform infrared(FTIR) spectra and density functional theory(DFT) calculations.The tiny PtPd nanoclusters have much higher catalytic activity and durability than commercial Pt/C,Pd/C and 3.5 nm PtPd nanoparticles.The present study shows that the metalreactant interaction plays a decisive role in determining the catalytic activity and cluster-support interaction plays a decisive role in enhancing the durability of electrocatalyst.The ratio and arrangement of Pt and Pd atoms on the surface of 1 nm PtPd cluster as well as the overall valence state,d-band center and specific surface area make them exhibit different catalytic performance and reaction mechanism from nanoparticle catalysts.In addition,in situ FTIR and DFT calculations showed that on the surface of PtPd clusters,the generation of CO_(2)through trans-COOH intermediate is the most optimal reaction pathway for the FAEO. 展开更多
关键词 CLUSTER Formic acid oxidation ELECTROCATALYSIS In situ FTIR Reaction mechanism
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Understanding Mass Dependence of Glass Formation in Ring Polymers
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作者 Xiang-Yu Song Zhen-Yue Yang +5 位作者 Qi-Lu Yuan Shang-Wei Li Zi-Qiang Tang Yue-Tong Dong Shi-Chun Jiang Wen-Sheng Xu 《Chinese Journal of Polymer Science》 SCIE EI CAS CSCD 2023年第9期1447-1461,I0008,共16页
Having highly tunable molecular topology is one of the most important characteristics of polymers that provides these materials with a wide range of interesting and unique properties.In particular,ring polymers exhibi... Having highly tunable molecular topology is one of the most important characteristics of polymers that provides these materials with a wide range of interesting and unique properties.In particular,ring polymers exhibit a number of properties that are markedly distinct from their linear counterparts.Here,we compare and contrast the glass formation of unknotted,nonconcatenated ring and linear polymer melts having variable molecular mass based on molecular dynamics simulations of a coarse-grained model.After revealing an unusual property in the structure of small rings,we discuss the mass dependence of the structural relaxation time determined from the self-intermediate scattering function over a wide range of temperatures in both ring and linear polymers.As a general trend,we find that the characteristic temperatures(e.g.,the glass transition temperature)and fragility of glass formation increase with increasing molecular mass in linear polymers,but the mass dependences of these properties are rather weak in the family of ring polymer models considered,in broad accord with experimental measurements.Importantly,we show that the glass formation of ring polymers can quantitatively be described by the string model,a model that is broadly consistent with the entropy theory of glass formation and that takes the mass of string-like clusters as a molecular realization of the abstract cooperatively rearranging regions.This opens the possibility of applying the configurational entropy-based theories to describe the glass formation of ring polymers,once the ring topology is taken into account. 展开更多
关键词 Ring polymers Glass formation String model Molecular dynamics simulation
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A single magnetic nanoplatform-mediated combination therapy of immune checkpoint silencing and magnetic hyperthermia for enhanced anti-cancer immunity
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作者 Zhiyu Yang Xiaoya Guo +5 位作者 Meng Meng Tong Li Huapan Fang Zhaohui Tang Huayu Tian Xuesi Chen 《Nano Research》 SCIE EI CSCD 2023年第8期11206-11215,共10页
As a revolutionary cancer treatment strategy,immunotherapy has attracted great attention.However,the effect of immunotherapy such as immune checkpoint blockade(ICB)is usually limited by insufficient immune response in... As a revolutionary cancer treatment strategy,immunotherapy has attracted great attention.However,the effect of immunotherapy such as immune checkpoint blockade(ICB)is usually limited by insufficient immune response in the body.Herein,a polycation-based magnetic nanocluster platform was developed to load therapeutic nucleic acids,which could achieve gene therapy-mediated ICB and efficient magnetic hyperthermia therapy(MHT).The silencing of immune checkpoints together with MHT-induced immunogenic cell death(ICD)effectively alleviated the immune escape of cancer cells and significantly enhanced the visibility of cancer cells to the immune system.This combined treatment strategy activated a strong adaptive anti-cancer immune response in vivo,greatly inhibiting tumor growth,metastasis and recurrence. 展开更多
关键词 magnetic nanoclusters gene therapy immune checkpoint silencing magnetic hyperthermia therapy cancer immunotherapy
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