通讯机构：
[Jincheng Fan; Zisheng Chao] C;College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha, Hunan, 410114, China
摘要：
Three dimensional FeCo2O4@MnO2 core-shell nanocomposites with a unique spherical structure were prepared on nickel foam by a two-step hydrothermal + annealing method and they show the specific area capacitance 4.2 F/cm2 at a current density of 2 mA/cm2, which is nearly four times higher than that of a single FeCo2O4 electrode (1.1 F/cm2). The assembled FeCo2O4@MnO2//active carbon solid-state asymmetric supercapacitor (ASC) has a specific area capacitance of 1.81 F/cm2, an energy density of 54.3 Wh/kg and a power density of 769.6 W/kg at 10 mA/cm2. The solid-state ASC exhibited an initial capacitance retention of 62.4% after 7000 cycles, demonstrating good cycling stability. Especially, the integrated solid-state asymmetric supercapacitors based on FeCo2O4@MnO2 electrode material were constructed in different connected manners. The series supercapacitor devices demonstrated the typical enhancement of the operating voltage window and the parallel devices significantly improved the capacitance. Therefore, the FeCo2O4@MnO2 electrode material exhibited the outstanding electrochemical performances in solid-state supercapacitors and promising practical application prospects in integrated circuits for energy storage.
摘要：
Lead-free double perovskite Cs2AgBiBr6 has attracted much attention due to its environmental stability and low toxicity, which has bee used in photovoltaic devices. Unfortunately, the power conversion efficiency (PCE) is relatively low owing to poor-quality film. In this paper, CuBr2 was added in the precursor to improve the crystalline of the perovskite film. Maybe Cu2+ was reduced to Cu + by DMSO, so Cu + existed in the Cs2(Ag1-xCux)BiBr6 perovskite films. The carbon electrode-based and hole-free solar cells with the planar structure of FTO/c-TiO2/Cs2(Ag1-xCux)BiBr6/C were fabricated. The effect of CuBr2 content on the performance of solar cells were studied. When the content of CuBr was 1 at.%, the solar cell exhibited the optimal PCE of 1.30%, which was increased by 52%, compared with the original solar cell. And the PCE for the planar structure in this work was the highest, compared with that in the other reported works.
关键词：
Urea oxidation reaction;Ethanol oxidation reaction;H2 production
摘要：
In this study, FeCo2O4@Co3O4 bifunctional catalysts with a unique structure combining nanosheets and nanowires were prepared on nickel foam by a simple hydrothermal + annealing method. The catalysts exhibited excellent catalytic activity for hydrogen pro-duction during urea electrooxidation reaction (UOR) and ethanol oxidation reaction (EOR). For UOR, the potential at 10 mA/cm2 current density is 1.387 V and the tafel slope is 67 mV/ dec. In the configured two-electrode electrolytic cell, the FeCo2O4@Co3O4 catalysts in the UOR and EOR processes required only 1.425 and 1.471 V, respectively, to produce a current density of 10 mA/cm2, which is much less than that of the (oxygen evolution reaction) OER (1.640 V). In addition, the current density remained stable at a fixed potential during a long time (20 h) i-t test in the urea solution.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
摘要：
This study explores using high-energy pulsed laser to improve the surface property and corrosion behavior of Ti6Al-4V, aiming to develop a more eco-friendly and efficient approach. The study comprises conventional cast samples, advanced 3D-printed samples, and their respective laser-treated counterparts, all tested in a 3.5 wt% NaCl solution. The findings showed that sample 3 (as-3D-printed) had a more stable passivation film than sample 1 (as-cast). The laser-treated surface of sample 2 (laser-treated cast) greatly enhances film stability and resistance. Moreover, sample 4 (laser-treated 3D-printed) exhibited significantly better corrosion performance compared to sample 3 (as-3D-printed) due to the increased thickness of the passivation film in the laser-treated samples, resulting in higher film corrosion resistance. The results reveal that laser remelting treatment can eliminate macroscopic defects, reduce grain size, increase grain boundary density, and generate denser and more stable passivation films on the surface of Ti-6Al-4V, leading to reduced corrosion currents during dynamic potential polarization. Furthermore, laser remelting treatment has the capability to transform and refine the & alpha; phase into a finer lamellar and needle-like structure, thereby increasing the density of passivation nucleation sites during the corrosion process, resulting in the formation of a high-density passivation layer, and ultimately improving the corrosion resistance. By gaining a better understanding of the underlying mechanisms involved in high-energy pulsed treatment, this work provides valuable insights that can be used to optimize the treatment process and improve the overall surface properties of Ti-6Al-4V alloys.
作者：
Jiang, H.;Yu, K. P.;Liu, X. C.;He, L. H.;He, B. B.;...
期刊：
Scripta Materialia,2023年237:115683 ISSN：1359-6462
通讯作者：
Huang, M;He, B
作者机构：
[Jiang, H.; Huang, M. X.; Yu, K. P.; Huang, M] Univ Hong Kong, Dept Mech Engn, Pokfulam Rd, Hong Kong, Peoples R China.;[He, B. B.; Yu, K. P.] Southern Univ Sci & Technol, Dept Mech & Energy Engn, Shenzhen 518055, Peoples R China.;[Liu, X. C.] Changsha Univ Sci & Technol, Inst Met, Coll Mat Sci & Engn, Changsha 410114, Peoples R China.;[He, L. H.] Chinese Acad Sci, Inst Phys, Beijing Natl Lab Condensed Matter Phys, Beijing 100190, Peoples R China.;[He, L. H.] Spallat Neutron Source Sci Ctr, Dongguan 523803, Peoples R China.
通讯机构：
[Huang, M ] U;[He, B ] S;Univ Hong Kong, Dept Mech Engn, Pokfulam Rd, Hong Kong, Peoples R China.;Southern Univ Sci & Technol, Dept Mech & Energy Engn, Shenzhen 518055, Peoples R China.
摘要：
The concept of compositionally complex alloy (CCA) has recently been applied in developing compositionally complex oxide (CCO). In this contribution, we discovered a new CCO with a spinel structure that is embedded in a new body-centered cubic CCA matrix. The crystal structure of the newly found CCO is characterized by neutron diffraction and high-resolution transmission electron microscopy. It is found that the chemical formula of the new CCO is Mn(V,Ti,Al)2O4, where the Mn atoms occupy the tetrahedral position while the V, Ti and Al atoms share the octahedral sites. The elements that take the octahedral sites are interchangeable. The mechanical behavior was characterized by nano-indentation experiments and the localized strength of CCA is effectively promoted with the existence of CCO. The present work illustrates that the combination of new CCO with new CCA matrix could be a new strategy to develop new oxide-metal composites.
作者机构：
[Yao, Meng; Zhao, Guoying; Ruan, Qinqin; Liu, Jiaxin; Dong, Haotian; Zhang, Haitao; Fang, Wenhao; Yuan, Xuedi] Chinese Acad Sci, Inst Proc Engn, Beijing Key Lab Ion Liquids Clean Proc, Beijing 100190, Peoples R China.;[Ruan, Qinqin; Zhang, Haitao] Univ Chinese Acad Sci, Sch Chem Engn, Beijing 100049, Peoples R China.;[Yuan, Du] Changsha Univ Sci & Technol, Coll Mat Sci & Engn, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Haitao Zhang] B;Beijing Key Laboratory of Ionic Liquids Clean Process, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China<&wdkj&>School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
摘要：
Current available organic liquid electrolytes of electrochemical energy devices lead to fast performance degra-dation and even combustion. Such challenges call for the development of advanced electrolytes with remarkable safety and electrochemical performances. Via integrating the merits of ionic liquids and liquid crystals, the emerging ionic liquid crystals (ILCs) enable the feasibility of design, manipulation of defined ion transport channels through modulated nanosegregated structures, and the high operational safety. Previous reviews rarely focus on the ion conductive and working mechanisms of ILC electrolytes in energy storage and conversion de-vices, which are critical for the development of superior electrolytes. Hence, our review is oriented to construct a key scheme of component-(micro)structure-fundamental-properties-electrochemical interaction of ILC electro-lytes for energy storage applications. Especially, the ion transportation mechanism and working principles of ILC electrolytes are comprehensively summarized to highlight their ion redistribution ability and high stability. Moreover, the challenges and design rules of ILC electrolytes are outlined to thrill their development in energy storage fields.
摘要：
A nano‐sintering strategy is developed for densifying sodium titanate nanostructures whilst minimizing grain growth. In this process, the intake of phosphate group energetically drives the consolidation of nano‐titanate and modulate the electronic structure for improved conductivity. Together with the pre‐incorporation of hydrophilic carbon, the strategy creates bulk‐density nanocomposites for high‐performing energy storage applications. Abstract Nanostructured electrode materials have attracted enormous attention because of their kinetic advantages endorsed by nanoscale regime. Densification is required to improve their volumetric densities for practical applications but is challenged by the loss of kinetic features. In this work, a nano‐densification strategy is developed by co‐sintering nanosized titanate with a phosphate agent and acid‐treated carbon black. Experimental studies reveal that the formation of Ti─O─P bonds energetically facilitates the dissociation of crystal water in titanate, enabling lower‐temperature consolidation of the nanostructures that avoids grain growth. Simultaneously, phosphorylation improves charge carrier concentration and electron conductivity of the titanate. Together with the incorporation of hydrophilic carbon black, the treated nano‐titanate electrode reaches a bulk‐level compaction density of 2.35 g cm−3. As an anode for Li‐ion batteries, the densified electrode shows improved electrochemical performance with a specific capacity of 88.4 mA h g−1 at 20 A g−1. When pairing with a high‐voltage LiNi0.5Mn1.5O4 cathode, the hybrid device demonstrates an outstanding combination of energy and power densities. Open access publishing facilitated by The University of Queensland, as part of the Wiley ‐ The University of Queensland agreement via the Council of Australian University Librarians.
摘要：
Application of water-based supercapacitor is largely limited by the disadvantages regarding electrolyte leakage and electrolyte corrosion. To address these issues, herein, a quasi-solid-state supercapacitor based on carbon felt (CF) electrode with PVA-KI/H2SO4 mixed gel electrolyte has been fabricated and an stable uniform acetalized polyvinyl alcohol (UAPVA) membrane in acidic condition has been reported for the first time. Given the excellent chemical and mechanical properties, the UAPVA membrane can facilitate I- transportation and still be restored to its original shape after stretching, bending and twisting, which is highly desirable for advanced flexible quasi -solid-state device applications. The as-prepared device exhibits outstanding electrochemical performance with bending 180o and then recovering to 0o. The specific capacitance remains 90.2% after 2400 cycles at 0.75 mA cm-2, indicating its good mechanical flexibility and stability. Remarkably, four quasi-solid-state supercapacitors can easily light up a red LED. The acquired electrochemical results highlight the promise of a successful mem-brane preparation strategy for the development of quasi-solid-state supercapacitors. Meanwhile, the addition of redox agents to traditional electrolyte solutions can be an effective way to achieve high-performance energy storage devices.
通讯机构：
[Zhe Zhou; Weiguo Mao; Zhe Zhou Zhe Zhou Zhe Zhou; Weiguo Mao Weiguo Mao Weiguo Mao] C;College of Materials Science and Engineering, Changsha University of Science and Technology, Changsha, 410114 China<&wdkj&>Science and Technology on Advanced Ceramic Fibers and Composites Laboratory, National University of Defense Technology, Changsha, 410073 China
摘要：
After the W coating is heat treated at 1500 °C for 1 h, W2C and dense WC layers are formed at the surface and interface, respectively. During ablation, the WC covered with pyrolytic carbon overcomes its brittleness and shows better ablation resistance by forming a chemical bond with pyrolytic carbon to prevent the penetration of oxygen. To improve the ablation resistance of C/C composites, tungsten (W) coating is applied by chemical vapor deposition (CVD) technology on C/C composites. Results show that the coatings are dense, with a thickness of about 400 μm. After heat treatment at a temperature of 1500 °C for 1 h, the main component of coating is W2C. Additionally, a dense WC layer forms on the surface of pyrolytic carbon (PyC). The sample subjected to heat treatment remains relatively intact after ablation at 3000 °C for 60 s, with a mass and linear ablation rate of 1.83 × 10−5 g s−1 and 3.03 × 10−5 cm s−1, respectively. The high‐temperature stability of WC formed on PyC and the filling of fiber gaps to prevent oxygen penetration are the main reasons for the improved ablation resistance of W‐coated C/C composites.
通讯机构：
[Li, LJ; Liu, K ] H;Hunan Inst Sci & Technol, Coll Chem & Chem Engn, Prov Key Lab Fine Petrochem Catalysis & Separat, Yueyang, Peoples R China.
关键词：
kinetic analysis;living anionic technology;poly(1,3-pentadiene-co-syrene-co-1,1-diphenylethylene) resins;unique alternating strategy;“bond-forming initiation” theory
摘要：
The combination of a living anionic technology and a unique alternating strategy provided an exciting opportunity to prepare novel and well-defined poly(1,3-pentadiene-co-syrene-co-1,1-diphenylethylene) resins consisting of three alternating sequences of modules (A/B/C zwitterions). "A" being Styrene (St)/1,3-pentadiene (PD), "B" being diphenylethylene (DPE)/PD, "A" being DPE/St, respectively, A wide composition range of new polyolefin resins, i.e., poly (A-co-B), poly (A-co-C), and poly (B-co-C), with controlled molecular weight and very narrow molecular weight and composition distributions have been prepared by a one-pot living characteristic method. In the section of kinetic analysis, the terpolymer yields and kinetic parameters were strongly dependent on the feed/comonomer ratio as well as the content of the alternating structure. The competition copolymerization behaviors of A/B, B/C, and A/C were studied in detail in this work. By contrast, the microstructure and the thermal property of the resulting terpolymer were investigated via Nuclear magnetic resonance (NMR) and Differential scanning calorimetry (DSC) analysis. The results of 1H NMR tracking the change of [Aromatic ring]/[C=C] value indicated the distinctive copolymer-ization behavior of the selective "alternating-modules". The glass transition temperature (T(g)) was very sensitive to the terpolymer composition. By contrast to poly(A-ran-B) with only one obvious T(g), there were two T(g)s in the A/C and B/C copolymerization cases. Moreover, the desirable high T(g) ~ 140 °C resin was limited to the terpolymers with up to 50 mol % DPE. Finally, the "ABC-X" mechanism was proposed to interpret the unique terpolymerization behavior, which belongs to the classical "bond-forming initiation" theory.
作者机构：
[Chen, Yi-Fei; Li, Fu-Jin; Li, Jia-Hong; You, Si-Hang; Liu, Tian-Tian; Liu, Peng; Chen, Shu-Guang] Changsha Univ Sci & Technol, Sch Mat Sci & Engn, Changsha 410114, Peoples R China.;[Gao, Meng-Qi] Natl Univ Singapore, Fac Engn, Dept Mat Sci & Engn, Singapore 117576, Singapore.;[Zhang, Fei-Fei] Jilin Univ, Sch Mat Sci & Engn, Changchun 130022, Peoples R China.
通讯机构：
[Shu-Guang Chen; Fei-Fei Zhang] S;School of Materials Science and Engineering, Changsha University of Science and Technology, Changsha, China<&wdkj&>School of Materials Science and Engineering, Jilin University, Changchun, China
关键词：
Bifunctional;Electrodeposition;Gradient hybrid;NiFe layered double hydroxides (NiFe LDHs);Overall water splitting
摘要：
NiFe layered double hydroxides (NiFe LDHs) have been intensively developed for the oxygen evolution reaction (OER) in alkaline media; however, their unsatisfactory hydrogen evolution reaction (HER) performance limits their practical application in overall water splitting. Herein, a simple and efficient one-step electrodeposition method is used to accomplish in situ growth of NiFe LDHsNiFe alloy gradient hybrid coatings on a carbon cloth (CC). Within the binder-free electrode, NiFe LDHs nanosheets with a low-crystalline nature exhibit highly active bifunctional OER/HER activities, and the NiFe alloy acts as a stable electron highway and strong skeleton bridge between NiFe LDHs and the CC. When the electrodes are simultaneously employed as the cathode and anode for overall water splitting, they require low cell potentials of 1.441 V at 10 mA-cm(-2) and 1.703 V at 100 mA-cm(-2), respectively, and they demonstrate outstanding stability at a current density greater than 100 mA-cm-2 for more than 100 h. This is one of the best bifunctional OER and HER catalysts for overall water splitting. Both lattice defects and surface reconstructions crucially contribute to the bifunctional OER/ HER activities of NiFe LDHs. This simple and scalable synthesis approach presents an intriguing paradigm for industrial production, and the fabricated electrode has potential application in high-current-density water splitting.
摘要：
Gradient nanostructured materials are regarded as a promising class of architectures with tunable mechanical properties, primarily dependent on the optimization of well-controlled fabrication parameters. In this paper, a microvariable-based constitutive model is incorporated into an integrated finite analysis technique. This approach correlates the fabrication parameters of surface mechanical grinding treatment (SMGT) with the corresponding measured mechanical properties of gradient structured (GS) materials, quantifying the relationship between process parameters, microstructure, and mechanical properties. Through theoretical prediction and experimental verification, it is observed that grain refinement, mechanical strength, and surface hardness are enhanced by increasing processing times and reducing path spacing. The yield stress of the fabricated GS material ranges from 126.8 MPa to 162.2 MPa, an increase of above 2.5 times compared to the original material, with a slight decrease in uniform elongation by a factor of 25.8 %, indicative of an excellent strength-ductility trade-off. The underlying mechanism for improved strength-ductility synergy is discussed, focusing on the importance of the tunable spatial distribution of grain size. This work sheds light on the potential application of gradient nano grained structures at an industrial scale and advances the fundamental understanding of strengthening mechanisms in gradient nanostructures. & COPY; 2023 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
