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Preparation,optical properties and energy transfer of SrLaAlO4:Dy3+,Eu3+

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Journal of Rare Earths 2024年第11期42卷 2058-2067页

作者： Wei Chen Heng Zhang Desheng Zhu school of Physic and Optoelectronic {1. Yangtze University

A series of Dy3+/Eu3+single doped and co-doped SrLaAlO4phosphors was synthesized by the traditional high-temperature solid-state method,and their structure,morphology and optical properties were *** X-ray diffraction（XRD） shows a small amount of doping with Dy3+and Eu3+does not change the crystal structure of the matrix SrLaAlO4and the best synthesis temperature is 1.50℃.The scanning electron microscopy（SEM） indicates the particle size directly ranges from 1.to 5μm roughly and the energy dispersive spectroscopy（EDS） patterns show that SrLaAlO4:Dy3+phosphor and SrLaAlO4:Dy3+,Eu3+phosphor were successfully ***4:Dy3+phosphor can be effectively excited by near-ultraviolet light,producing two strong emission lights at 483 nm（blue light） and 579 nm（yellow light）,presenting a cold white light;SrLaAlO4:Eu3+phosphor can be effectively excited by nearultraviolet light,producing red lights at 622 nm;the characteristic emission peaks of Dy3+and Eu3+can be shown simultaneously under the same excitation wavelength in SrLaAlO4:Dy3+, Eu3+*** changing the relative doping concentration ratio of Dy3+and Eu3+,the modulation of SrLaAlO4:Dy3+,Eu3+phosphor from cold white to warm white light can be *** addition,the study of the luminescent mechanism and lifetime shows that there is energy transfer between Dy3+and Eu3+in SrLaAlO4:Dy3+,Eu3+phosphor.

关键词： Energy transfer High-temperature solid-phase method Luminescence properties Rare earths SrLaAlO4: Dy3+, Eu3+ White phosphor

One dimensional CeO_(2) nanorods/poly(ethylene oxide) solid composite electrolyte for all-solid-state lithium-ion batteries

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Journal of Rare Earths 2024年第3期42卷 570-577,I0005页

作者： Yudi Guo Erqing Zhao Xiaofang Zhao Shuailei Liu school of Chemistry and Materials {1. Xinxiang UniversityXinxiang453003China school of Chemistry and Chemical {1. Henan Institute of Science and TechnologyXinxiang453003China

The research of poly(ethylene oxide)(PEO)-based solid composite electrolyte with high ionic conductivity and excellent interfacial stability is the key to the development of all-solid-state lithium-ion batteries(ASSLIBs). Herein, uniform nanorod structured CeO_(2) fillers were controllably synthesized by electrospinning, which were subsequently filled into PEO polymer to prepare CeO_(2)/PEO solid composite electrolyte. The addition of CeO_(2) nanorods can reduce both the glass transition temperature and the melting point of PEO polymer, and also interact with PEO and lithium bis(trifluoromethanesulphonyl)imide(LITFSI) by Lewis acid—base reaction. Therefore, the solid composite electrolyte exhibits a high ionic conductivity of 4.52 × 1.^(-4)S/cm, a wide electrochemical stability window of about 4.8 V, and a good interfacial stability with Li at 55℃. Moreover, the LiFePO_4/Li ASSLIB divulges the discharging specific capacity of 1.5, 1.2, 1.6 and 1.6 mA,h/g at 0.2, 0.5, 1.and 2 C, respectively, and achieves the capacity retention of 90.3% after 1.0 cycles at 0.5 C. Consequently, one dimensional CeO_(2) nanorods can be considered as an alternative filler for polymeric solid electrolyte.

关键词： Poly(ethylene oxide) Solid composite electrolyte CeO_(2)nanorods Ionic conductivity Rare earths

Enhancing solar-driven overall water splitting via both sacrifice and noble metal free photocatalysis: copper cluster/boron-doped carbon nitride catalysts

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Science China Chemistry 2024年第11期67卷 3886-3896页

作者： Yun-Dong Cao Yuxi Zhang Jian Song Hong Liu Zhiyuan Song Lin-Lin Fan Cai-Li Lv Guang-Gang Gao school of Materials Science and {1. University of Jinan

The major impediment to the additional industrialization of water splitting is the high cost of the co-catalyst made of noble metals and the sacrificial reagent. A binary photocatalytic system, consisting of B-doped g-C3N4nanosheets(Cu20@BCN-X) and atomically accurate copper clusters, is designed in this study. The copper clusters serve as co-catalysts for H2evolution and exhibit Pt-like activity, whereas the nanosheets serve as carriers and semiconductor components for O2evolution. Such binary system, created using simple techniques, demonstrates hydrogen bonding interactions that promote synergistic effects and efficient binding and charge transfer across the interface between the two components. Band position manipulation of carbon nitride nanosheets demonstrates a Z-scheme charge transfer mechanism between the nanosheets and copper clusters. This photocatalytic system can accomplish the photocatalytic overall water splitting process(259.9 μmol g-1.-1.f H2and 1.9.4 μmol g-1.-1.f O2) without using sacrificial agents or noble metal co-catalysts. This work lays the foundation for the design of overall water splitting catalysts by precisely manipulating the energy levels, and it also paves the way for commercialized photocatalytic catalysts that do not require noble metals or sacrificial chemicals.

关键词： copper clusters band modulation photocatalysts water splitting

Boosting cycling stability by regulating surface oxygen vacancies of LNMO by rapid calcination

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Nano Research 2024年第4期17卷 2671-2677页

作者： Haoran Jiang Cuihua Zeng Wei Zhu Jiawei Luo Zhedong Liu Jingchao Zhang Rui Liu Yunhua Xu Yanan Chen Wenbin Hu school of Materials Science and {1. Tianjin UniversityTianjin 300072China school of Materials Science and {1. Shandong University of Science and TechnologyQingdao 266590China

Spinel LiNi_(0.5-x)Mn_(1.5+x)O_(4)(LNMO)has attracted intensive interest for lithium-ion battery due to its high voltage and high energy ***,severe capacity fade attributed to unstable surface structure has hampered its *** vacancies(OVs)tend to occur in the surface of the material and lead to surface structure reconstruction,which deteriorates the battery performance during electrochemical ***,we utilize high-temperature-shock(HTS)method to synthesize LNMO materials with fewer surface *** calcination drives lower surface OVs concentration,reducing the content of Mn^(3+)and surface reconstruction layers,which is beneficial to obtain a stable crystal *** LNMO material synthesized by HTS method delivers an initial capacity of 1.7 mAh·g^(-1. at 0.1.C and capacity retention of 81.6%after 300 cycles at 1.C,and exhibits excellent performance at low temperature.

关键词： ultrafast synthesis oxygen vacancy LiNi_(0.5-x)Mn_(1.5+x)O_(4)(LNMO)cathode high-temperature-shock lithium-ion batteries

High-rate metal-free MXene microsupercapacitors on paper substrates

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Carbon Energy 2024年第5期6卷 94-104页

作者： Han Xue Po‐Han Huang Lee‐Lun Lai Yingchun Su Axel Strömberg Gaolong Cao Yuzhu Fan Sergiy Khartsev Mats Göthelid Yan‐Ting Sun Jonas Weissenrieder Kristinn BGylfason Frank Niklaus Jiantong Li school of Electrical {1. and Computer Science KTH Royal Institute of TechnologyStockholmSweden school of {1. Sciences KTH Royal Institute of TechnologyStockholmSweden

MXene is a promising energy storage material for miniaturized microbatteries and microsupercapacitors(MSCs).Despite its superior electrochemical performance,only a few studies have reported MXene-based ultrahigh-rate(>1.00 mV s^(−1.)on-paper MSCs,mainly due to the reduced electrical conductance of MXene films deposited on ***,ultrahigh-rate metal-free on-paper MSCs based on heterogeneous MXene/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)-stack electrodes are fabricated through the combination of direct ink writing and femtosecond laser *** a footprint area of only 20 mm^(2),the on-paper MSCs exhibit excellent high-rate capacitive behavior with an areal capacitance of 5.7 mF cm^(−2)and long cycle life(>95%capacitance retention after 1.,000 cycles)at a high scan rate of 1.00 mV s^(−1.,outperforming most of the present on-paper ***,the heterogeneous MXene/PEDOT:PSS electrodes can interconnect individual MSCs into metal-free on-paper MSC arrays,which can also be simultaneously charged/discharged at 1.00 mV s^(−1.,showing scalable capacitive *** heterogeneous MXene/PEDOT:PSS stacks are a promising electrode structure for on-paper MSCs to serve as ultrafast miniaturized energy storage components for emerging paper electronics.

关键词： direct ink writing femtosecond laser scribing MXene on-paper microsupercapacitors PEDOT:PSS ultrahigh rate capability

Minimum mass-entransy dissipation profile for one-way isothermal diffusive mass-transfer process with mass-resistance and massleakage

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Science China(Technological Sciences) 2024年第8期67卷 2427-2435页

作者： CHEN LinGen XIA ShaoJun Institute of Thermal Science and Power engineering Wuhan Institute of TechnologyWuhan 430205China school of Mechanical Electrical EngineeringWuhan Institute of TechnologyWuhan 430205China school of Power {1. Naval University of EngineeringWuhan 430033China

As a new concept,mass-entransy is one of the twins in the core of entransy *** can describe mass-transfer ability for masstransfer processes(MTPes),just as thermal-entransy for describing heat-transfer ***,mass-entransy dissipation can be utilized to evaluate the loss of mass-transfer *** mass-entransy dissipation(MMED) is utilized to optimize one-way isothermal diffusive MTPes with mass-leakage and mass-transfer law(g ∝ Δ(c),where c means concentration).For a given net amount of mass-transferred key components at the low-concentration side,optimality-condition for the MMED of isothermal diffusive MTPes is obtained by using the *** of the amount of mass-transferred and mass-leakage on optimal results are analyzed,and the obtained optimization profiles are compared with those for MTP profiles of constant-concentration-difference(c_1.c_2=const) and constant-concentration-ratio(c_1.c_2=const).The product of square of key-component-concentration(KCC) difference between high-and low-concentration sides and inert component concentration at high-concentration side for the MMED of the MTP with no mass-leakage is a constant,and the optimal relationship of the KCCs between high-and low-concentration sides with mass-leakage is significantly different from the *** mass-leakage is relatively small,the MTP with c_1.c_2=const strategy is superior to that with c_1.c_2=const strategy,and the latter is superior to the former with an increase in mass-leakage.A combination of mass-entransy concept,finite-time thermodynamics,and averaged-optimization-method is a meaningful tool for optimizing MTPes.

关键词： diffusive mass-transfer-law mass-leakage one-way isothermal mass-transfer minimum mass-entransy dissipation finite-time thermodynamics averaged-optimization-method

Particle aggregation and breakage kinetics in cemented paste backfill

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International Journal of Minerals,Metallurgy and Materials 2024年第9期31卷 1965-1974页

作者： Liuhua Yang Hengwei Jia Aixiang Wu Huazhe Jiao Xinming Chen Yunpeng Kou Mengmeng Dong school of Civil and {1. Henan Polytechnic UniversityJiaozuo 454000China school of Civil and Environmental {1. University of Science and Technology BeijingBeijing 100083China

The macroscopic flow behavior and rheological properties of cemented paste backfill(CPB)are highly impacted by the inherent structure of the paste *** this study,the effects of shear-induced forces and proportioning parameters on the microstructure of fresh CPB were *** size evolution and distribution of floc/agglomerate/particles of paste were monitored by focused beam reflection measuring(FBRM)technique,and the influencing factors of aggregation and breakage kinetics of CPB were *** results indicate that influenced by both internal and external factors,the paste kinetics evolution covers the dynamic phase and the stable *** the mass content or the cement-tailings ratio can accelerate aggregation kinetics,which is advantageous for the rise of average floc ***,the admixture and high shear can improve breaking kinetics,which is beneficial to reduce the average floc *** chord length resembles a normal distribution somewhat,with a peak value of approximate 20μ*** particle disaggregation con-stant(k_(2))is positively correlated with the agitation rate,and k_(2) is five orders of magnitude greater than the particle aggregation constant(k1..The kinetics model depicts the evolution law of particles over time quantitatively and provides a theoretical foundation for the micromechanics of complicated rheological behavior of paste.

关键词： cemented paste backfill particle kinetics admixture rheology

Macro electrochemical milling and its hybrid variants

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Chinese Journal of Aeronautics 2024年第8期37卷 1-35页

作者： Ningsong QU Xiaolong FANG Junzhong ZHANG Huanghai KONG Yang LIU Minglu WANG Xiaokang YUE Yuehong MA Zhihao SHEN Jiajie CHEN College of Mechanical and Electrical engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China school of Mechanical {1. Jiangsu UniversityZhenjiang 212003China school of Mechanical {1. Jiangsu University of Science and TechnologyZhenjiang 212003China school of Mechanical {1. Hefei University of TechnologyHefei 230009China

Macro electromechanical milling has recently attracted increasing attention because numerous large thin-walled structures composed of difficult-to-cut materials are employed in the aerospace *** paper reviews recent developments in state-of-the-art macro electromechanical *** fundamental aspects of material removal mechanisms,such as the generation and breakdown behaviors of passive oxide films of typical difficult-to-cut materials,were *** methods for breaking down passive films are summarized,and simulation methods for the machining process coupling multiple physical fields are *** electrochemical milling methods,including fly mode electrochemical milling and sink electrochemical milling,are *** made to improve process performance,such as the material removal rate,surface quality,and machining accuracy,are *** addition,the main hybrid electrochemical milling methods,including electrochemical discharge milling,mechano-electrochemical milling,and electrochemical mill grinding,are also presented.

关键词： Electrochemical machining Electrochemical milling Material removal rate Surface quality Electrochemical discharge milling Electrochemical millgrinding

Re-delocalization of localized d-electrons in VO_(2)(R)-VS_(4)hetero-structure enables high performance of rechargeable Mg-ion batteries

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Journal of Magnesium and Alloys 2024年第5期12卷 1830-1840页

作者： Lijiao Zhou Chao Shen Xueyang Hou Zhao Fang Ting Jin Keyu Xie school of Materials Science and {1. Northwestern Polytechnical UniversityXi’an 710072China school of Metallurgical {1. Xi’an University of Architecture and TechnologyXi’an 710055China

Rechargeable Mg-ion batteries(MIBs)have attracted much more attentions by virtue of the high capacity from the two electrons ***,the reversible Mg^(2+)diffusion in cathode materials is restricted by the strong interactions between the high-polarized bivalent Mg^(2+)ions and anionic ***,we design and propose a hetero-structural VO_(2)(R)-VS_(4)cathode,in which the re-delocalized d-electrons can effectively shield the polarity of Mg^(2+)***,the electrons should spontaneously transfer from VS_(4)to VO_(2)(R)through the interfaces of hetero-structure due to the lower work function value of VS_(4).Furthermore,the internal electrons transfer lead to the electronic injection into VO_(2)(R)from VS_(4)and the partially broken V-V dimers,indicating the presence of lone pair electrons and charge *** from the shield effect of re-delocalized electrons,and the weakened attraction between cations and O/S anions enables more S^(2-)-S_(2)^(2-)redox groups to participate the electrochemical reactions and compensate the double charge of Mg^(2+)***,VO_(2)(R)-VS_(4)hetero-structure exhibits a high specific capacity of 554 mA h g^(-1.at 50 mA g^(-1..It is believed that the charge re-delocalization of cathode extremely boost the Mg^(2+)ions migration for the high-capacity of MIBs.

关键词： Mg-ion batteries Cathode Charge delocalization Electronic structure Heterostructure