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OBJECTIVE: Accumulating evidence indicates that circular RNAs (circRNAs) contribute to breast cancer (BC) development and progression. However, the role of circ_0058063 in BC and its underlying molecular processes remain unclear. METHODS: The expression of circ_0058063, miR-557, and DLGAP5 in BC tissues and cells was determined using real time quantitative PCR or western blotting. The functions of circ_0058063 in BC cells were detected using CCK-8, Transwell, caspase-3 activity, and xenograft tumor assays. The specific binding of circ_0058063/miR-557 and DLGAP5/miR-557 was verified using RNA immunoprecipitation (RIP) and dual-luciferase reporter assays. RESULTS: circ_0058063 expression was upregulated in BC tissues and cells. circ_0058063 knockdown inhibited proliferation and migration but promoted apoptosis in MCF-7 and MDA-MB-231 cells in vitro. In vivo studies further validated that the knockdown of circ_0058063 repressed tumor growth. Mechanistically, circ_0058063 directly sponged miR-557 and negatively regulated its expression. Additionally, miR-557 inhibition reversed the tumor-suppressive effects of the circ_0058063 knockdown on the survival of MDA-MB-231 and MCF-7 cells. Moreover, miR-557 directly targeted DLGAP5. DLGAP5 knockdown suppressed MCF-7 and MDA-MB-231 cell growth, and these effects were reversed by miR-557 downregulation. CONCLUSION: Our findings verify that circ_0058063 acts as a sponge for miR-557 to upregulate DLGAP5 expression. These findings suggest that the circ_0058063/miR-557/DLGAP5 axis is an important regulator of oncogenic function and may be a promising therapeutic target for BC. [ABSTRACT FROM AUTHOR]

Given its safer working potential and higher theoretical capacity, Li3VO4 has become a potential alternative anode material to graphite. However, the hydrophilicity, low electrical conductivity, and unsatisfactory reaction kinetics of the Li3VO4 anode pose a challenge. In this paper, a graphene-wrapped Li3VO4@rGO hybrid was prepared using a novel efficient uniform rotation solvothermal (URS) method. Graphene with high electrical conductivity accelerates the reaction kinetics of the anode material to improve its rate performance. The URS method restrains the agglomeration of particles to shorten the diffusion paths of Li+. The uniform reaction obtained by this method and the lamellar shape of graphene synergistically enlarge the specific surface area of Li3VO4 to supply additional active sites for the extraction/insertion of Li+. Therefore, Li3VO4@rGO–R exhibits superior cycling performance (249.5 mA h g−1 after 4000 cycles at 5 A g−1) and rate performance (243.3 mA h g−1 at 10 A g−1). This study provides a versatile and efficient method for enhancing the electrochemical performance of anode materials. [ABSTRACT FROM AUTHOR]

Ingenious morphology design and doping engineering have remarkable effects on enhancing conductivity and reducing volume expansion, which need to be improved by transition metal oxides serving as anode materials for lithium-ion batteries. Herein, S0.15–Fe2O3@C nano-spindles with a hierarchical porous structure are obtained by carbonizing MIL-88B@PDA and subsequent high-temperature S-doping. Kinetic analysis showed that S-doping increases capacitive contribution, enhances charge transfer capability and accelerates Li+ diffusion rate. Therefore, the S0.15–Fe2O3@C electrode exhibits superior lithium storage performance with a remarkable specific capacity of 1014.4 mA h g−1 at 200 mA g−1, ultrahigh rate capability of 513.1 mA h g−1 at 5.0 A g−1, and excellent cycling stability of 842.3 mA h g−1 at 1.0 A g−1 after 500 cycles. Moreover, the size of S0.15–Fe2O3@C particles barely changed after 50 cycles, indicating an extremely low volume expansion, related to the carbon shell, fine Fe2O3 nanoparticles, abundant voids inside, and improved kinetics. This strategy can be applied to other metal oxides for synthesizing anodes with high-rate capability and low volume expansion. [ABSTRACT FROM AUTHOR]

All-solid-state Li-ion batteries, have become increasingly important because of their highly reliable solid electrolyte materials. Flexible solid polyethylene oxide (PEO) based electrolytes have been widely studied. Nevertheless, this material exhibits low lithium-ion conductivity. Herein, we report the optimisation of the composition of PEO/polyvinylidene fluoride (PVDF)-based electrolytes to enhance ionic conductivity. When the weight ratio of lithium bis(trifluoromethane sulphonyl)imide and PEO/PVDF is 1:5 (LiTFSI:PEO/PVDF = 1:5), maximum conductivities are 2.98 × 10−5 S cm−1 at 30°C and 5.56 × 10−4 S cm−1 at 60°C. Furthermore, the all-solid-state battery using this solid electrolyte film, a Li metal anode, and a LiFePO4 cathode delivers initial discharge capacities of 149.6 mAhg−1 (0.1 C, 60°C) and 130.2 mAh g−1 (0.5 C, 60°C). Meanwhile, the solid-state lithium battery also presents good cycling performance and excellent rate capability at 60°C. [ABSTRACT FROM AUTHOR]

Embedded fiber optic sensors are considered a promising technology that can unlock the black box within a battery and understand the fundamental internal chemical and physical states during operation. However, the interfacial compatibility between the implanted fiber sensor and electrode materials has not yet been investigated. In this study, a fiber Bragg grating (FBG) sensor is incorporated into a solid-state lithium-metal coin cell at different interfaces to explore the resulting variations in electrochemical property. The presence of the fiber sensor accelerates the capacity fade compared with that of a pristine cell. To address this issue, a new method is employed to reduce the sensor diameter from 250 μm to 30 μm while preserving its sensing function. The reduction in the sensor diameter enhances its compatibility with the size of the electrode materials. Integrating a micro-FBG (MFBG) sensor into the solid-state cell also alleviates the defects related to interface stratification and void growth, leading to the improved capacity retention. Moreover, the feasibility of utilizing MFBG for in-situ monitoring of internal stress within a lithium-metal cell is demonstrated. This technique offers a scalable solution for the noninvasive monitoring of battery state, thereby improving the reliability and safety of cells. • Embedded optical fiber sensor affected solid-state lithium-metal cell performance. • Microfiber sensor improves the contact between embedded sensor and electrodes. • Operando monitoring of stress inside lithium-metal batteries by microfiber sensor. [ABSTRACT FROM AUTHOR]

Transition metal sulfides appear excellent electrochemical properties in the realm of anode for sodium-ion batteries and hold significant potential for practical application in large-scale devices in the future. However, their development is hindered by inferior inherent conductivity and tremendous volume strain during discharge and charge processes. In this study, Co 1-x S@C nanoboxes were synthesized utilizing Co-Co PBA as a precursor. The electrochemical sodium storage performance of Co 1-x S@C electrode was characterized, revealing an extremely long-life and stable performance. At 1.0 A g−1 and 2.0 A g−1, the electrode delivered capacities of 255.8 mAh g−1 and 197.6 mAh g−1 after 5000 and 10,000 cycles respectively, with negligible capacity attenuation. The pseudo-capacitance behavior of Co 1-x S@C NBs electrode in sodium storage was quantitatively calculated through CV test at varying sweep speeds. The significant contribution of pseudo-capacitance resulted in its exceptional rate capacity and electrochemical stability. Furthermore, kinetic analysis revealed that the existence of a carbon shell enhanced the Na+ diffusion kinetics and charge transfer kinetics of Co 1-x S@C NBs. This strategy provides a reference for enhancing the Na+ storage performance of other transition metal sulfides. [ABSTRACT FROM AUTHOR]

The design of a reasonable structure and component regulation are valid methods for enhancing the electrochemical properties of TiO 2 , which serves as prominent anode in sodium-ion batteries with exceptional structural stability. Herein, the carbon-coated anatase TiO 2 doped with S (S-TiO 2 @C) was synthesized via a facile metal-organic framework-assisted approach. The S atoms partially substitute oxygen atoms in the lattice, thereby enhancing the capacitive behavior, facilitating charge transfer kinetics, and augmenting the diffusion coefficient of Na+. With exceptionally high porosity and substantial carbon content, the caky S-TiO 2 @C electrode manifests superior rate capability of 167.7 mAh g−1 at 5.0 A g−1 and long-cycle life of 239.0 mAh g−1 at 2.0 A g−1 over 4000 cycles. It is foreseeable that the strategy of anionic doping and carbon coating on the metal oxide with porous structure to optimize the sodium storage capability of the electrode will be applied in the future. • Metal-organic framework derived S-doped TiO 2 with carbon coating was synthesized for the first time. • The high level of porosity facilitates electrolyte infiltration and offers more active sites for sodium storage. • The S atoms partially substitute oxygen atoms in the lattice, thereby enhancing the kinetics of sodium storage. • The S-TiO 2 @C electrode exhibits superior rate capability and long-term cycle stability over 4000 cycles. [ABSTRACT FROM AUTHOR]

The H 2 V 3 O 8 /MXene film shows excellent electrochemical properties as cathode material for aqueous zinc-ion batteries and solid-state zinc-ion batteries. [Display omitted] • H 2 V 3 O 8 /MXene film has been synthesized by hydrothermal method and coating method. • Combination MXene and H 2 V 3 O 8 synergistically improves electrochemical properties. • The H 2 V 3 O 8 /MXene film shows excellent performance for AZIBs and solid-state ZIBs. In this study, freestanding H 2 V 3 O 8 /MXene (HVO/MX) film were synthesized by high temperature mixing hydrothermal method and coating method. The composite film exhibits good electrical conductivity and flexibility. In addition, HVO/MX film shows excellent electrochemical properties when used as cathode material for aqueous zinc ion batteries (ZIBs) and solid-state ZIBs. The aqueous ZIBs assembled from the HVO/MX film shows satisfactory specific capacity (highest specific capacity can reach 346 mAh/g at 10 A/g) and cycling performance. Surprisingly, the assembled quasi-solid-state batteries can work well at room temperature and low temperature conditions. The battery maintained a high discharge specific capacity of 180 mAh/g after 3000 cycles at 25 °C. The outstanding performance of the HVO/MX film assembled battery is due to its good electrical conductivity, zinc-ion diffusion rate and simple battery structure. This work provides a novel route for the preparation of self-supporting cathode materials for different battery system. [ABSTRACT FROM AUTHOR]

• A new method is proposed for batch preparation microfiber Bragg grating (MFBG) sensors using alkaline solution with safety and the high efficiency. • The smooth-surfaced MFBG sensors were produced with a roughness of less than 100 nm, which is nearly 30 times lower compared to the widely-used HF etching method. • The method can achieve diameter customization of MFBG sensor by controlling time with an error of only ± 1.2918 μm. • The effects of diameter reduction of FBG sensors on their optical property, sensing performance, and mechanical property were systematically investigated. Microfiber Bragg grating sensors hold great promise given their compactness and large evanescent field effect. The fabrication method of the sensors plays a pivotal role in determining the performance. In this study, a novel approach for batch manufacturing microfiber Bragg grating sensors was proposed using a NaOH solution under hydrothermal conditions. Compared to other methods, it is simpler, safer, and more efficient. Through precisely controlling the reaction time, 50 microfiber Bragg grating sensors were produced with smooth surfaces, exhibiting a surface roughness of about 87 nm, and achieved tailored fiber diameters with an error of only ± 1.2918 μm. In addition, the sensors with different diameters produced by the method to systematically investigate the effects of diameter reduction on various aspects, including spectral characteristics, temperature, strain, refractive index sensing, and bending performance, accompanied by theoretical explanations. [ABSTRACT FROM AUTHOR]

In this study, dopamine@BaTiO3 whiskers/P(VDF-HFP) nanocomposite films with high charge energy density were successfully prepared by a simple solution casting method. The BaTiO3 whiskers has been obtained under an optimized two-step hydrothermal condition. To alleviate the interfacial incompatibility, the BaTiO3 whiskers are modified by dopamine coating. The structure and morphology of dopamine@BaTiO3 whiskers have been well confirmed through XRD, SEM, and TEM. Further performance characterization of the nanocomposite films indicates that higher addition of BaTiO3 whiskers gives better dielectric properties and energy density. However, enhanced energy storage and high breakdown strength of nanocomposite can be obtained simultaneoulsy under suitable content.The maximal discharged energy density of the nanocomposite films with 5 vol% dopamine@BaTiO3 whiskers can reach 9.02 J/cm3, and the discharged efficiency remain 46.29% at 300 MV/m. These findings reveal a straightforward approach to improve the performance of the nanocomposite films. [ABSTRACT FROM AUTHOR]

This work presents the effects of sintering temperature ranging from 1200 °C to 1300 °C at intervals of 20 °C on the crystal structure, ferroelectric properties, and electrocaloric effect (ECE) of Pb 0.8 Ba 0.2 ZrO 3. Samples sintered at 1240 °C, 1260 °C, and 1280 °C have large remanent polarization and small coercive field. Meanwhile, samples sintered at 1260 °C, 1280 °C, and 1300 °C possess large breakdown field strength. Samples sintered at 1260 °C for 4 h exhibit the optimal ferroelectric properties. Antiferroelectricity-ferroelectricity (AFE-FE) phase transition occurs at room temperature T 1 (279 K). Directly examining ECE at this temperature is meaningful, and the temperature change is 0.068 K at approximately 60 °C and 30 kV/cm. Results laid the foundation for studying the performance of ferroelectric and ECE within this phase-transition temperature range and provide a reference for new solid-state refrigeration technology. [ABSTRACT FROM AUTHOR]

In this study, we adopt a facile two-step annealing strategy to synthesize different structural 3D Fe2O3 micro-cubes and 3D Fe3O4 micro-cubes using Prussian blue (PB) as a precursor. Importantly, the effect of the annealing temperature on the structural evolution of the products is systematically investigated. In the first step, the 3D Fe2O3 cubes are synthesized by annealing PB in air. With the increasing temperature, the morphology of 3D Fe2O3 changes from the cube with pores on surface to the hollow cube assembled by nanosheets (HCNSs), which is caused by the higher gas generation and overflow. In the second step, 3D Fe3O4 cubes are obtained by annealing 3D Fe2O3-HCNSs in the atmosphere of Ar/H2. With the increasing temperature, the morphology of 3D Fe3O4 changes from the hollow cube assembled by nanosheets to the hierarchical porous hollow cube assembled by fine nano-particles (denoted as HCNPs), an interesting micro/nano-structure that is obtained by recrystallization and reduction. When the temperature is excessive, the building blocks become larger and the 3D structures collapse. Furthermore, we evaluate the electrochemical performance of 3D hierarchical porous Fe3O4-HCNPs as the anode materials for Li-ion batteries. They exhibit enhanced electrochemical performance, characterized by a large reversible capacity of 1193.6 mA h g−1 at a current density of 100 mA g−1 and a high rate capacity of 942.1 mA h g−1 at 1000 mA g−1. This superior performance is due to the unique structural advantages of 3D hierarchical porous Fe3O4-HCNPs, including abundant meso/micro-pores, hollow structure and robust structural stability. [ABSTRACT FROM AUTHOR]

Abstract As cathode materials for Li-ion batteries (LIBs), V 2 O 5 , possessing a large-spaced and open layered crystal structure, have attracted considerable attention due to their distinct advantages of high specific capacity, abundant raw materials and low cost. Although low-dimensional nanostructured V 2 O 5 can increase the discharge capacity of LIBs, it still suffers from poor cycling and rate performance due to serious self-aggregation and pulverization. Building micro/nano-structures is a highly promising method to address the above issues. Herein, we propose a facile oxidation strategy to successfully synthesize the unique 3D hierarchical porous sponge-like V 2 O 5 micro/nano-structures (V 2 O 5 -SLMNSs) by using the structure-similar sponge-like VO 2 (B)@C micro/nano-structures as a precursor. Importantly, as-synthesized V 2 O 5 -SLMNSs possess the distinct structural advantages of a robust structure with large surface area and abundant meso/micropores, which are beneficial for achieving a better electrochemical performance. Specific capacity during the second discharge for V 2 O 5 -SLMNSs is 232 mAh/g at 100 mA/g, with 87% of the capacity being maintained after 50 cycles, which is considerably higher than the discharge capacity (190 mAh/g) in the second cycle and the value for the capacity retention (69%) of 1D V 2 O 5 nanoribbons. Thus, as-synthesized V 2 O 5 -SLMNSs are promising cathode materials for the next-generation LIBs. Graphical abstract Image 1 Highlights • Unique 3D sponge-like V 2 O 5 micro/nano-structures (V 2 O 5 -SLMNSs) are synthesized. • V 2 O 5 -SLMNSs possess robust structure, large surface area and conductive frameworks. • V 2 O 5 -SLMNSs exhibit the greatly improved electrochemical performance. [ABSTRACT FROM AUTHOR]

Sodium cobalt oxides (Na x CoO 2 , denoted as NCO) have attracted considerable attentions as the promising candidate of high-temperature thermoelectric materials because of their high thermoelectric power, high thermal stability and non-toxicity. The performances of NCO materials are dependent on their crystal structure. In this paper, the crystal structure and thermoelectric properties for NCO samples prepared by the solid state method under different sintering temperatures are discussed. Importantly, a phase transformation is discovered in NCO ceramics by TG-DTA analysis. The structural transformation is probably caused by Na volatilization at high temperature. With increasing sintering temperature, the Na ion concentration decreases, and the valence state of the Co ions increases, which can influence the carriers transport properties. In addition, a large number of grain boundaries generated by the fine grain prepared under low sintering temperature can effectively decrease the thermal conductivity. Thus, the figure-of-merit ZT value can be enhanced by the large Seebeck coefficient and low thermal conductivity in the low-temperature phase. [ABSTRACT FROM AUTHOR]

In this study, we demonstrated the co-modification of oxygen vacancies and heterojunctions in VO 2 (B) (V O –VO 2 /MXene) as a cathode material for zinc-ion batteries (ZIBs). VO 2 nanobelts are uniformly distributed on MXene nanosheets, which providing complete electron transport channels during the insertion or de-insertion of Zn2+. The formation of oxygen vacancies provides additional active sites and enhances the conductivity of VO 2. Density functional theory calculations reveal that the oxygen vacancies effectively facilitate reversible intercalation/deintercalation process, which results in rapid intra-crystal zinc ion diffusion. The combination of V O –VO 2 with MXene introduces an interfacial electric field, ultimately leading to synergistic enhancement in electrochemical activity. The V O –VO 2 /MXene composite exhibits the highest specific capacity (287 mAh g−1) at 10 A g−1 and excellent cycling lifespan (253 mAh g−1 after 3000 cycles) for ZIBs. This work provides a reliable strategy for the co-modification of metal oxide electrodes with oxygen vacancies and heterostructures. [Display omitted] • VO 2 /MXene heterojunctions with oxygen vacancies were synthesized via HTMM. • Oxygen vacancy and heterointerfaces lead to the superior zinc ion diffusion kinetic. • The synergistic effect of oxygen vacancy and heterointerfaces was demonstrated. • ZIBs shows high specific capacity, excellent rate capability and good cycle lifespan. [ABSTRACT FROM AUTHOR]

With revolutionary electric vehicles and the smart grid fast developing, more advanced energy storage technologies become quite crucial issues. Li-ion batteries (LIBs) and Na-ion batteries (NIBs) are considered as the most promising electrochemical energy storage technologies. Low-dimensional nano-structural electrode materials can greatly increase the specific capacity, but they still suffer from poor cycling and rate performances due to their serious self-aggregations. Constructing 3D structures, such as micro/nano-structures and free-standing electrodes, is a quite promising method to address the above issues. Such 3D structures can simultaneously avoid the disadvantages of low-dimensional nanomaterials, and preserve their advantages. As one group of promising high-capacity and low-cost electrode materials, vanadium-based oxides have exhibited an quite attractive electrochemical performance for energy storage applications in many novel works. However, their systematic reviews are quite limited, which is disadvantageous to their further development. Herein, this article provides an overview of vanadium-based oxides in the applications of LIBs and NIBs by focusing mainly on the aspect from low-dimensional nanomaterials synthesis to 3D micro/nano-structures and free-standing electrodes fabrication. Moreover, a feasible strategy to controllably fabricate the 3D micro/nano-structure for the whole vanadium-based oxides family is presented. Furthermore, and importantly, a quite promising solution method for the practical commercialized applications of vanadium oxides cathode materials in the future is proposed, i.e., fabricating the 'vanadium oxides-based cathode/solid electrolyte/Li metal anode-type' all solid-state secondary-ion batteries. [ABSTRACT FROM AUTHOR]

The increasing demand for high-energy-density portable electronics and electric vehicles is sparking an intensive research interest in lithium-ion batteries. Transition metal oxides/carbonaceous matrix hybrids have attracted tremendous attention to produce the next-generation lithium-ion batteries (LIBs). This paper initially reports that the tree-like Li 2 MnO 3 @carbon nanotube (CNT) hierarchical architecture can achieve the long-life lithium storage performance. Li 2 MnO 3 nanoparticles of the hybrid with lattice Li + , as the anode material for LIBs, exhibits a reversible capacity of over 740 mAh/g at a current density of 0.5 A/g after 350 cycles, indicative of superior cyclic stability and excellent rate performance. XPS and XRD patterns reveal that LiOH in the anode material, which originates from the conversion reaction, is further discovered to be available and reversible for surface-enhanced lithium storage. Surface-enhanced lithium storage contributes to the over-compensation and increased capacity. [ABSTRACT FROM AUTHOR]

As intercalation-type anode materials for Li-ion batteries (LIBs), the commercially used graphite and Li4Ti5O12 exhibit good cycling and rate properties, but their theoretical specific capacities are too low to meet the ever-growing demands of high-energy applications such as electric vehicles. Therefore, the development of new intercalation-type anode materials with larger capacity is very desirable. Herein, we design and synthesize novel 3 D hierarchical porous V2O3@C micro/nanostructures consisting of crumpled nanosheets, through self-reduction under annealing from the structurally similar VO2 (B)@C precursors without the addition of any other reducing reagent or gas. Excitingly, it is found for the first time through ex situ XRD technology that V2O3 is a new, promising intercalation-type anode material for LIBs with a high capacity. V2O3@C micro/nanostructures can deliver a large capacity of 732 mAh g−1 without capacity loss at 100 mA g−1 even after 136 cycles, as well as exhibiting excellent cycling and rate performances. The application of V2O3 for Na-ion batteries (NIBs) is elaborated for the first time, and excitingly, it is found that V2O3@C micro/nanostructures may be promising anode materials for NIBs. [ABSTRACT FROM AUTHOR]

In this article, monocrystalline bundles and polycrystalline nanowires were synthesized using α-MnO 2 and MnOOH as precursors via an in-situ reaction. The electrochemical properties of the resulting nanocrystals were investigated. Results reveal that the polycrystalline nanowires are more activated than the monocrystalline nanowires. The polycrystalline nanowires also deliver a maximum discharge capacity of 226 mA h/g at 10 mA/g. Compared with the linear charging plateau at >4.3 V in the monocrystalline bundles, the charging platues of (100) and (001) domains in the polycrystalline nanowires are 4.3–4.55 and 4.55–4.6 V, respectively. The high capacity and rate performance of the polycrystalline nanowires are attributed to their good electroconductivity and rapid Li + diffusion, which originate from defects and small domains. [ABSTRACT FROM AUTHOR]

• ZnS-MoS 2 /rGO composites were synthesized by using a one-step high-temperature mixing method (HTMM) under hydrothermal conditions. • The synthesis approach is implemented by using the self-designed dual-chamber Teflon lined reactor and ingenious rotation process. • The synergistic effect in the hybrid enhances electronic conductivity and structural stability. • The ZnS-MoS 2 /rGO@C composites with large proportion of pseudocapacitive contribution exhibits excellent rate capability. Hybrid-structured coupling metal dichalcogenides with carbon materials serve as prospective anode materials for lithium-ion batteries (LIBs) due to their high electrical conductivity, rich active sites, and Li+ diffusion path for Li+ storage. In the present work, graphene-wrapped ZnS−MoS 2 @carbon composites (ZnS−MoS 2 /rGO@C) are synthesized via high-temperature mixing during the hydrothermal and carbonation processes. The as-prepared ZnS−MoS 2 /rGO@C composites display alleviated volume change in the electrochemical process, increased Li+ diffusion speed, and improved conductivity, which are caused by the synergic effect of phase boundaries and hierarchical construction. Therefore, the ZnS−MoS 2 /rGO@C composites show superior lithium storage capacity and structure stability, and possess ultrastable cycle (581.0 mAh g−1 after 500 cycles at 1 A g−1) and good rate performance (310.7 mAh g−1 at 5 A g−1). This work confirms that anode materials with a hybrid structure can be rationally engineered for high-performance LIBs with superior cycle durability and good rate capability. [Display omitted] [ABSTRACT FROM AUTHOR]

The citrate complexing sol-gel process to fabricate lead-free (K,Na)NbO3 ferroelectric thin films was studied. Soluble niobium source of niobium-citric acid (Nb-CA) solution was utilized as a raw material to synthesize (K,Na)NbO3 thin films, by pyrolyzing at 450-550C and annealing at 650C. The film pyrolyzed at 450C shows poor crystallization with porous morphology, whereas the film pyrolyzed at 550C appear to be well-crystallized and denser, and the ferroelectricity was also proved by the - hysteresis loop measurement. [ABSTRACT FROM AUTHOR]

BaTiO nanoparticles were prepared for the first time employing a solvothermal process from the synthetic precursors of KTiO nano-whiskers. The obtained samples were characterized by X-ray diffraction, transmission electron microscopy, selected area electron diffraction, and high-resolution transmission electron microscopy, etc. The results indicate that well-crystallized single-phase BaTiO nanoparticles are synthesized using KTiO as precursors under solvothermal conditions at as low as 0.9 M. The solvothermal method facilitates the crystallinity and formation of the BaTiO nanoparticles. However, the K ions cannot be completely replaced by Ba by the hydrothermal method even at 10 M due to its unique and extremely stable 'tunnel' structure. The solvothermal method provides new avenues for the ion-exchange synthesis of a variety of other perovskite-type materials such as MTiO (M = Pb, Sr, Ca, etc.). [ABSTRACT FROM AUTHOR]

A simple low-temperature solid-state reaction in the presence of the surfactant PEG400 was developed to obtain ZnO/CdS nanocomposites. The effects of synthesis temperature and reaction time on crystal structure and optical properties of the nanocomposites were investigated by several technologies. X-ray diffraction (XRD) and high resolution transmission electron microscope (HRTEM) characterizations showed that the products consisted of the nanoparticles, and the grain growth kinetics of the cubic CdS and the hexagonal ZnO phase in the nanocomposites was described. The mechanism analysis suggested that sufficient grinding and heating treatment was a key to form the ZnO/CdS nanocomposites, and the surfactant PEG400 was proved not to involve the reaction and prevent the nanoparticles from aggregating to larger in whole grinding and heat-treatment process. Ultraviolet–visible (UV–vis) spectra revealed that the band gaps of the nanocomposites could be tuned by the reaction temperature and reaction time. Photoluminescence (PL) spectra showed that the changing position and the intensity of the emission peaks resulted from the rate of electron transfer and recombination probability under the different conditions. [ABSTRACT FROM AUTHOR]

• PEO-based 3D CPE-5 was prepared by reinforcing with PVDF-HFP nanofibers and LATP particles. • The thickness of 3D CPE-5 is only 50 μm with excellent mechanical strength. • 3D CPE-5 displays high electrochemical window (5.21 V) and lithium transference number (0.49). • 3D CPE-5 shows excellent stability to Li-metal and effective lithium dendrite inhibition. • High-voltage Li/3D CPE-5/NCM811 battery shows excellent cycling stability at 0.1 and 0.5 c. Solid-state lithium metal batteries (SSLMBs) are considered as a promising energy storage technology due to their high energy density and safety. However, the relatively low conductivity of solid-state electrolytes and the high electrolyte–electrode interfacial resistance seriously limited the development of SSLMBs. In this work, the high-performance PEO-based composite polymer electrolyte (3D CPE-5) was successfully prepared by reinforcing with polyvinylidene fluoride–hexafluoropropylene nanofibers and Li 1.3 Al 0.3 Ti 1.7 (PO 4) 3 (LATP) particles. The thickness of 3D CPE-5 is only 50 μm with high electrochemical window (5.21 V) and lithium transference number (0.49) at 60 ℃. In addition, the 3D CPE-5 shows excellent stability to Li–metal, so that Li–Li symmetric cells can run stably for more than 300 h under 0.1 mA cm−2 with low voltage polarization value (15 mV) and effective lithium dendrite inhibition. Finally, the high-voltage Li/3D CPE-5/NCM811 (LiNi 0.8 Co 0.1 Mn 0.1 O 2) solid-state battery demonstrates excellent cycling stability at 0.1 and 0.5 C (60 ℃). The excellent safety performance of 3D CPE-5 highlights its remarkable advantages over liquid electrolytes and provide an effective design strategy of high-performance polymer electrolytes for SSLMBs. [Display omitted] [ABSTRACT FROM AUTHOR]

• 2D V 6 O 13 nanosheets were one-step synthesized using URH for the first time. • URH is a simple, low–energy consumption, time-saving, and efficient synthesis technology. • The as-synthesized material has a superior rate/cycle performance and enhanced reversible capacity. The ever-growing demands of Lithium-ion batteries (LIBs) for high-energy and long-life applications, such as smart grids and electrical vehicles, have drawn great research interest. Herein, 2D V 6 O 13 nanosheets with good crystallinity and robust configuration are in situ synthesized by applying an interesting one-step uniform rotate hydrothermal method. X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy were carried out to characterize the crystal structure and micromorphology of the samples. In addition, the lithium storage performance of the sample was investigated through cyclic voltammetry, electrochemical impedance spectroscopy, and charge/discharge tests. Their capacity is up to 240 mAh g-1 at a current density of 100 mA g-1, corresponding to an initial Coulombic efficiency as high as 98.41%. Moreover, the capacity of 199 mAh g-1 can be delivered at a large current density of 500 mA g-1, and 87% of the capacity can be retained after 100 cycles. Even at a larger current density of 1000 mA g-1, they can still deliver a high capacity of 155.7 mAh g-1, and nearly 80% of the initial capacity can be kept after 300 cycles. This result is much higher than that of V 6 O 13 prepared by traditional hydrothermal method under the same test conditions. These results demonstrate that the as-synthesized 2D V 6 O 13 nanosheets by uniform rotate hydrothermal method have a promising future for high-rate and long-life cathode materials of next-generation LIBs. [ABSTRACT FROM AUTHOR]

A one-step surfactant-free hydrothermal route is developed to prepare platelike NaNbO3 template powders. At optimal KOH concentration, pure platelike NaNbO3 with rhombohedral structure (width and thickness of 20 and 2 μm, respectively) is obtained at 200°C for 16 h. After calcination at 600°C for 4 h, the structure of the hydrothermally synthesized NaNbO3 changes from rhombohedral to orthorhombic, whereas the initial platelike morphology is maintained. Such characteristics in terms of phase structure, elemental composition, and morphology render our hydrothermally synthesized NaNbO3 suitable for textured ceramic fabrications. [ABSTRACT FROM AUTHOR]

Dielectric capacitors with high power density are essential components in advanced electronic and micro-electronic products. Nevertheless, the limited energy storage density and efficiency, coupled with poor performance at elevated temperatures, severely restrict their usefulness. In this work, Ta was introduced to the (Ag 0.80 Bi 0.04 Sr 0.04)NbO 3 ceramic prepared via the hydrothermal-synthesized powders to improve the room- and high-temperature energy storage performance. A large breakdown strength of 729 kV/cm, a high recoverable energy storage density of 8.5 J/cm3 and a benign energy efficiency of 75.6% were simultaneously achieved in (Ag 0.80 Bi 0.04 Sr 0.04)(Nb 0.85 Ta 0.15)O 3 ceramics. Moreover, the larger energy storage efficiency (83.5%) at elevated temperatures than room temperature, the benign frequency and cycle stability foreshow great potential in realizing the application of capacitors at high-temperatures. [ABSTRACT FROM AUTHOR]

Eu(OH)3 with various shape-controlled morphologies and size, such as plate, rod, tube, prism and nanoparticles was successfully synthesized through simple hydrothermal reactions. The products were characterized by XRD (X-Ray Powder Diffraction), FE-SEM (Field Emission- Scanning Electron Microscopy) and TG (Thermogravimetry). The influence of the initial pH value of the starting solution and reaction temperature on the crystalline phase and morphology of the hydrothermal products was investigated. A possible formation process to control morphologies and size of europium products by changing the hydrothermal temperature and initial pH value of the starting solution was proposed. [ABSTRACT FROM AUTHOR]

Sodium-ion batteries (SIBs) are considered promising energy storage devices owing to the abundant reserve and low-cost accessibility of Na resources. However, such batteries suffer from poor electrochemical performance due to the larger diameter of Na ions (0.106 nm). In this study, nitrogen-doped carbon-coating interlayer-expanded MoS 2 porous nanosheets (MoS 2 @N–C) were synthesized, and their structural, morphological, and electrochemical properties were characterized. The XPS and EDS indicated the successful introduction of carbon into the MoS 2 nanosheets. The interlayer spacing for (002) plane was increased from 0.62 nm to 0.78 nm corresponding to the shift toward lower angles shown in XRD. The MoS 2 @N–C exhibited an impressively high reversible capacity of 352 mAh/g at a current density of 100 mA/g after 200 cycles; this capacity is five times higher than that of bare MoS 2. Moreover, MoS 2 @N–C showed excellent rate performance due to the boosted diffusion of Na ions. The observed improvement in the electrochemical performance of MoS 2 @N–C demonstrates that the combination of suitable composite materials and interlayer expansion are effective strategies for battery technologies based on the storage of large ions. Image 1 • A high-temperature mixing method under hydrothermal conditions was utilized. • CTAB acts as intercalating reagent to perform interlayer engineering for MoS 2 @N–C. • The porous, flower-like few-layered MoS 2 @N–C nanosheets were obtained. • The interlayer spacing of (002) planes of MoS 2 @N–C increased from 0.62 nm to 0.78 nm. • The physical mechanisms for the enhanced electrochemical properties were addressed. [ABSTRACT FROM AUTHOR]

The unique antiferroelectric behavior of AgNbO 3 ceramics has great potential for energy storage applications, which have attracted increasing attention. However, the relatively low recoverable energy storage density, energy efficiency and breakdown strength of AgNbO 3 ceramics severely limit their application in practice. In the present work, (Bi 0.2 Sr 0.7)TiO 3 was introduced to improve the relaxation behavior in AgNbO 3 ceramics via two-step sintering, which contributed to a high breakdown strength of 580 kV/cm. A recoverable energy storage density of 7.8 J/cm3 and an energy efficiency of 56 % were obtained in 0.90AgNbO 3 -0.10(Bi 0.2 Sr 0.7)TiO 3 ceramics. Moreover, the benign energy storage performance could be maintained at elevated temperatures, variable frequencies and cyclings up to 105. These results demonstrate the great potential of AgNbO 3 -based ceramics for energy storage applications. [ABSTRACT FROM AUTHOR]

High‐capacity vanadium‐based oxides are one kind of promising energy storage materials, especially for electric vehicles. It has become a hot research issue to synthesize vanadium‐based oxides from low‐dimensional nanostructures to 3D micro/nano‐structures and free‐standing‐electrodes. It will become a very attractive and practical strategy in the future to fabricate the “vanadium oxides‐based cathode/solid electrolyte/Li metal anode‐type” all solid‐state secondary‐ion batteries. This is reported by Pengcheng Liu, Kongjun Zhu, and co‐workers in article number 1700547. [ABSTRACT FROM AUTHOR]

Pure TiO2 and 3% Y-doped TiO2 (3% Y-TiO2) were prepared by a one-step hydrothermal method. Reduced TiO2 (TiO2-H2) and 3% Y-TiO2 (3% Y-TiO2-H2) were obtained through the thermal conversion treatment of Ar-H2 atmosphere at 500 °C for 3 h. By systematically comparing the crystalline phase, structure, morphological features, and photocatalytic properties of 3% Y-TiO2-H2 with pure TiO2, 3% Y-TiO2, and TiO2-H2, the synergistic effect of Y doping and reduction of TiO2 was obtained. All samples show the single anatase phase, and no diffraction peak shift is observed. Compared with single-doped TiO2 and single-reduced TiO2, 3% Y-TiO2-H2 exhibits the best photocatalytic performance for the degradation of RhB, which can be totally degraded in 20 min. The improvement of photocatalytic performance was attributed to the synergistic effect of Y doping and reduction treatment. Y doping broadened the range of light absorption and reduced the charge recombination rates, and the reduction treatment caused TiO2 to be enveloped by disordered shells. The remarkable feature of reduced TiO2 by H2 is its disordered shell filled with a limited amount of oxygen vacancies (OVs) or Ti3+, which significantly reduces the Eg of TiO2 and remarkably increases the absorption of visible light. The synergistic effect of Y doping, Ti3+ species, and OVs play an important role in the improvement of photocatalytic performances. The discovery of this work provides a new perspective for the improvement of other photocatalysts by combining doping and reduction to modify traditional photocatalytic materials and further improve their performance. [ABSTRACT FROM AUTHOR]

Bismuth ferrite–barium titanate (BFO–BT) is a well‐known lead‐free ferroelectric material with a large electric field‐induced strain; however, its piezoelectricity is very low under low electric fields. Herein, by studying Ca‐doped BFO–BT ceramics, multiple structural evolutions are found in the ferroelectric domains at the morphotropic phase boundary (MPB) in BFO–BT‐based ceramics, where a part of the local ferroelectric domains reveals a transition from rhombohedral to tetragonal and to relaxor phases. The superior electrical properties with large electrostrain Sp of 0.38%, large Pr of 38.4 μC cm−2, intermediate d33 of 132 pCN−1, and high TC of 425 °C are obtained at the MPB in these ceramics. Multiple local domain structural evolutions with compound ferroelectric domains and relaxor phases are responsible for the large electrostrain and intermediate piezoelectricity. This can explain the inconsistent piezoelectric response under high and low electric fields at the MPB in the BFO–BT‐based ferroelectric ceramics. [ABSTRACT FROM AUTHOR]

Rapid developments in revolutionary electric vehicles have led to an increase in the energy-density and cycling-life requirements for Li-ion batteries (LIBs). The binary transition metal oxide NiCo 2 O 4 is attracting considerable attention due to its much larger specific capacity than graphite. However, NiCo 2 O 4 suffers from poor cycling performance owing to a large volume change during cycling. To address this problem, we proposed an easy strategy to fabricate in situ carbon-coated NiCo 2 O 4 bilayered hybrid nanostructural arrays supported on Ni foam (denoted as NiCo 2 O 4 @C BHNAs–NF) as free-standing anodes for LIBs through a sucrose-assisted hydrothermal method. The in situ-synthesized uniform carbon shell can simultaneously buffer the volume change during cycling and increase the conductivity. The micro/nano-structure also possessed outstanding structural advantages, such as large surface area and hierarchical porous characters, enabling NiCo 2 O 4 @C BHNAs–NF to have excellent electrochemical performance. Its capacity can reach 1298 mAh/g at a current density of 100 mA/g, and 86% of the initial capacity can be retained after 100 cycles. All these results revealed that NiCo 2 O 4 @C BHNAs–NF was a promising candidate anode for next-generation LIBs. [ABSTRACT FROM AUTHOR]

The investigation of fine structural evolutions around the morphotropic phase boundary (MPB) is important to understand the origin of the high piezoelectricity in ferroelectric ceramics. Here, we report a new phase boundary associated with oxygen octahedral tilt–untilt transition by exploring average and local structural evolutions in the vicinity of MPB in Bi0.5Na0.5TiO3–PbTiO3 (BNT–PT) ceramics. It is found that the local structural change of the oxygen octahedral tilt–untilt transition is decoupled with the average structural change of the rhombohedral-to-tetragonal phase transition at MPB in BNT–PT. The slight octahedral tilting distortion at MPB is responsible for the large high-field-induced electrostrain and small low-field-induced piezoelectricity in BNT–PT. The crucial difference of MPB between BNT–PT and the classical piezoelectric Pb(Zr,Ti)O3 is discussed from their local structural evolutions of octahedral tilting to the performance changes at MPB. It helps us to figure out the origin of large high-field-induced electrostrain but small piezoelectricity in BNT-based ceramics. [ABSTRACT FROM AUTHOR]

The representatives of relaxor ferroelectric (1-x)Pb(Zn1/3Nb2/3)O3-xPbTiO3 (PZNT) and (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMNT) have been extensively studied due to their excellent dielectric and piezoelectric properties near the morphotropic phase boundary (MPB). However, low rhombohedral to tetragonal phase transition temperature and Curie temperature directly affect the performance and stability of devices, particularly for high-power ultrasonic transducers. In this paper, the large size tetragonal 0.62Pb(In1/2Nb1/2)O3-0.38PbTiO3 (PINT) crystal was grown by the modified Bridgman technique. The crystals were oriented along the ⟨ 100 ⟩ direction to make bars with electrodes on (001) faces. The variation of the dielectric constant with temperature showed that the Curie temperature of PINT was 250 °C, and the maximum dielectric constant was 7.29 × 104ɛ0. Fitting with Curie-Weiss's law, we obtained that the relaxation degree was 1.44, which could mean that the dielectric properties of PINT are between relaxor ferroelectric and ordinary ferroelectric. At room temperature, electromechanical coupling coefficient k31 and piezoelectric strain constant d31 were 0.56 and 551 pC/N, respectively. Piezoelectric properties were relatively stable between room temperature and 175 °C. The material has good temperature stability in terms of piezoelectricity and dielectric properties. These results proved that the working temperature of the PINT crystal could reach about 175 °C, much higher than PZNT and PMNT single crystal, indicating their application in ultrasonic transducers at high temperatures. [ABSTRACT FROM AUTHOR]

As one of binary transition metal oxides, NiCo 2 O 4 (NCO) suffers from several problems like self–agglomeration and drastic volume change when used as an anode for lithium–ion batteries (LIBs). Herein, we propose a facile one–step hydrothermal method combined with heat treatment to prepare a hierarchical micro–nano hydrangea–like NiCo 2 O 4 /V 2 O 3 composite array (denoted as NCO/VO) on a nickel foam substrate as a free–standing anode for LIBs. The V 2 O 3 is introduced to form a composite structure with NCO, improving the electronic and ionic conductivity of the electrode. The synergistic effect of porosity, composite structure and micro–nano architecture offers the electrode excellent electrochemical performance. The specific capacity of the as–prepared electrode is 1155.6 mA h g−1 after 200 cycles under the current density of 100 mA g−1, with a retention ratio of 91.02 %. When the current density rises to 1000 mA g−1, it delivers a specific capacity of 750 mA h g−1, showing excellent rate performance. This work demonstrates that NCO/VO–NF is a promising candidate anode for next–generation LIBs. [Display omitted] • A first–time synthesis of NiCo 2 O 4 –V 2 O 3 composite arrays on nickel foam by a facile method. • The unique hierarchical micro–nano hydrangea–like morphology. • Improved electrochemical performances as an anode for LIBs by introducing V 2 O 3. [ABSTRACT FROM AUTHOR]

Designed component of 0.95Al 2 O 3 –0.015Yb 2 O 3 –0.01MgO–0.025SiO 2 (95Al 2 O 3 –Yb/Mg/Si) ceramics were prepared by the traditional mixed-oxide method in the sintering temperature range of 1450–1700 °C. The influence of sintering temperature on the crystal structure, densification, microstructure, mechanical, friction and wear properties of 95Al 2 O 3 -YbMgSi ceramics were systematically investigated. XRD and SEM analysis results revealed that the increase in sintering temperature was very beneficial to eliminate the pores, increase the density and grain size, which obeys the common grain growth law. Both the flexural strength and hardness of obtained samples were increased almost linearly when the sintering temperature increased from 1450 °C to 1700 °C. The ceramics sintered at 1650 °C showed the optimum properties: H v = 1812.3, σ = 151.3 MPa, μ = 0.41, ρ = 3.72 g/cm3 and K c = 8.06e−5 mm3/N·m, respectively. Furthermore, the results of friction and wear experiments suggested that the 95Al 2 O 3 –Yb/Mg/Si ceramic prepared at the optimizing sintering process exhibited more stable friction state and lower wear degree under non-lubricated conditions. The enhanced mechanical properties could be attributed to their structure densification, pore elimination and gain growth with the increase of sintering temperature. [ABSTRACT FROM AUTHOR]

With the wearable electronics progressing rapidly, the demand for flexible, long-life and low-cost electrodes of Li-ion batteries (LIBs) becomes more and more urgent. Due to the abundant resources and low cost, silica (SiO 2 ), especially the amorphous one, has attracted a lot of interests on the application of anode materials for LIBs. However, SiO 2 still suffer from the poor cycling performance mainly caused by the huge volume change during cycling like other alloy-type materials. Furthermore, it remains a challenge to fabricate the SiO 2 –based flexible electrode. Herein, we propose a facile in situ strategy to fabricate the electrospun robust free-standing SiO 2 /carbon nanofibers (denoted as in-SCNFs) film constructed by N-doped carbon nanofibers encapsulating uniformly amorphous SiO 2 nanoparticles. The in situ synthesized finer SiO 2 nanoparticles in the in-SCNFs are uniformly encapsulated in flexible carbon nanofibers, which can effectively buffer the volume change. Furthermore, the robust in-SCNFs film possesses the excellent mechanical flexibility and strength. So, when served as the free-standing anode of LIBs, the in-SCNFs film exhibits superior cycling performance. A discharge specific capacity of 405 mAh/g can be delivered even after a long-term 1000 cycles at a large current density of 500 mA/g, and the retention is up to 115%. It is an exciting finding that the in-SCNFs film is also a long-life anode of Na-ion batteries (NIBs). The 99% of initial capacity can be kept after 250 cycles at 500 mA/g. To our best knowledge, this is the first report on the application of SiO 2 /C composite for NIBs. These results suggest that the as-fabricated in-SCNFs film can become one promising free-standing long-life anode for LIBs and NIBs. [ABSTRACT FROM AUTHOR]

Sodium niobate nanopowders (N-NaNbO 3 ) and submicron powders (M-NaNbO 3 ) were synthesized by the solvothermal and hydrothermal route, respectively. Subsequently, their sintering activities were comparably investigated through a modified solid-state sintering process. It's found that N-NaNbO 3 green bodies presented an apparent shrinkage after the calcination at 650 °C, and dense N-NaNbO 3 ceramics can be obtained at 950 °C. Besides, the optimized sintering temperature of N-NaNbO 3 ceramics was 100 °C lower, yet the shrinkage was four times larger when compared with M-NaNbO 3 samples. Importantly, N-NaNbO 3 samples showed improved dielectric properties in the whole frequency range, and the room temperature relative dielectric constant (ε r ) of N-NaNbO 3 samples sintered at 950 °C was as high as ~8000. The improved permittivity of N-NaNbO 3 samples was attributed to the compact microstructure, unique crystalline structure and less oxygen vacancies. At the same time, the effect of abnormal phase transition behavior originated from the metastable structure was considered to explain the enhanced room temperature permittivity. It's believed that the solvothermal route has great potentials in the synthesis of alkali niobate ceramics powders with high activity for low-temperature sintering. [ABSTRACT FROM AUTHOR]

Crystal size and microstructure are of great importance in determining the physical and chemical properties of functional materials, and refine powders, especially their assembled porous structures have potential application in ceramic fabrication, absorption, catalysts and drug delivery, due to their characters of high activity and large specific surface area. Herein, high temperature mixing method under hydrothermal condition (HTMM) was adapted to synthesize barium strontium titanate [(Ba, Sr)TiO 3 , BST] powders with various Ba/Sr ratios ( x = 0.5, 1.0, 3.0 and 4.0). In comparison with conventional hydrothermal synthesis (CHS), the effects of HTMM on grain refinement and porous structure formation were exclusively investigated. XRD and SEM results indicated that, in the given condition, BST powders prepared by HTMM were much smaller than that by CHS, especially at a lower Ba/Sr ratio. Additionally, assembled porous architectures were constructed by HTMM. It's believed that the high temperature mixing process and continuous rotation contributed to the grain refinement and assembled porous structure, respectively. The assumption was further confirmed through the synthesis of sodium niobate (NaNbO 3 ) powders by HTMM. It's demonstrated that HTMM is advantageous in preparation of refine powders and porous assembled architectures. [ABSTRACT FROM AUTHOR]

Cu 2 S thin films were successfully grown in situ on Cu foil by an easy hydrothermal method. The effects of surfactant and reaction time on the formation of the Cu 2 S films were studied by X-ray diffraction, field-emission scanning electron microscopy and ABIOS profilometry. Results showed that the thin films consisted of nanoparticles, and their crystallization and surface roughness depended on the structures of surfactants and reaction time. Photocatalytic studies indicated that the film obtained at 1 h by the EDTA-2Na surfactant exhibited a good methylene blue degradation rate of 83.7%, and higher values of 89.2% and 90% were obtained with increased reaction time to 3 and 4 h. Even the decomposition rate remained at high (82%) after reuse. This good catalytic performance can be attributed to the heterojunction formed between Cu and Cu 2 S, the special surface from the reaction between [Cu-EDTA] - ion and S 2− , and the further crystal orientation with prolonged reaction time. [ABSTRACT FROM AUTHOR]

Lead zirconate titanate Pb(Zr x Ti 1− x )O 3 films with various Zr/Ti ratios of 20/80, 40/60, 52/48, 60/40 and 80/20 are deposited on highly dense CoFe 2 O 4 ceramics using a simple chemical solution deposition. All Pb(Zr x Ti 1− x )O 3 films are polycrystalline and have no preferential orientations. The dielectric, ferroelectric, piezoelectric and magnetoelectric properties strongly depend on the Zr/Ti ratio. And the Pb(Zr x Ti 1− x )O 3 films with a Zr/Ti ratio close to morphotropic phase boundary exhibit best properties, whose magnetoelectric coefficient is over 1.5 times larger than those of other Zr/Ti ratios. The introduction of a PbO seeding layer between the Pb(Zr 0.52 Ti 0.48 )O 3 films and CoFe 2 O 4 substrates facilitates the (100)-texture. Therefore, the magnetoelectric coefficient was enhanced by 1.5 times. The further improvement of the magnetoelectric coupling could be anticipated by fabricating Pb(Zr 0.52 Ti 0.48 )O 3 films with more or absolute (100)-texture and using conductive interfacial layer between two phases. [ABSTRACT FROM AUTHOR]

To analyze the effect of PFN content on the microstructure and electrical properties of x Pb(Fe 0.5 Nb 0.5)O 3 –(0.57− x)Pb(Ni 1/3 Nb 2/3)O 3 –0.43Pb(Zr 0.3 Ti 0.7)O 3 , the doping of x PFN–PNN–PZT) were systematically studied with 0.015 ≤ x ≤ 0.075. XRD patterns and Raman spectra analysis reveal that PFN diffuses into PNN–PZT perovskite lattice and forms new quaternary solid solution. With the increase of PFN content x , the proportion of rhombohedral (R) phase decreases gradually, whereas the proportion of tetragonal (T) phase displays a contrary trend. In particular, R – T coexistence near MPB was observed at x = 0.045. Meanwhile, optimized electrical properties of d 33 = 961 pC/N, k p = 0.716, ε r = 6298, and tan δ = 3.1% are achieved for the 0.045PFN–PNN–PZT ceramics. Moreover, the ceramics at MPB showed larger remnant polarization P r = 24.55 μC/cm2, smaller coercive field E c = 0.36 kV/mm, and lower dielectric relaxor degree γ = 1.813. All these results reveal that the enhanced electrical properties could be attributed to synergistic phase boundary motion, dielectric relaxor behavior and ferroelectric hysteresis effect. [ABSTRACT FROM AUTHOR]

Composites comprising TiO 2 @MWCNTs (shell@core) nanoparticles and poly(vinylidene fluoride) (PVDF) were prepared through a two-step method, including solution cast and mechanical rolling, inducing a highly oriented structure with both PVDF lamellar and TiO 2 @MWCNTs. A systematic study was performed to investigate the crystalline structure and piezoelectric properties of composites. The obtained results reveal that greatly enhanced breakdown strength and piezoelectric properties can be achieved in composites by the incorporation of highly aligned TiO 2 @MWCNTs. A maximum piezoelectric coefficient d 33 of ∼41 pC/N can be achieved in composites at a loading level of 0.3wt.%, which is nearly double that of the pure PVDF. [ABSTRACT FROM AUTHOR]

Monodisperse Dy-doped BaTiO 3 nanopowders ( x DBT) with x =0, 1, 2, 3, 4, 5 mol% has been synthesized via a modified sol-hydrothermal method. And the influence of Dy 3+ on the crystal structure, micromorphology and dielectric properties of x DBT ceramics has been investigated. It’s found that Dy 3+ slightly affects the shape of the x DBT nanopowders, whereas excess Dy 3+ would cause the formation of the Dy(OH) 3 impurity. In addition, the grain growth during a sintering process is suppressed with the Dy 3+ incorporation. Further, the possible occupation of the Dy 3+ has been extrapolated based on the variation of lattice volume and phase composition. A self-compensation mode involving the simultaneously occupation at Ba-site and Ti-site is observed in the samples with 4 mol% Dy. Importantly, stabilized temperature-dependent dielectric properties has been achieved at x =4 mol%, resulting from the diffuse phase transition behaviors (the calculated diffuse factor γ =1.952) induced by chemical inhomogeneity. [ABSTRACT FROM AUTHOR]

Interface interactions between nanoparticles and polymer matrix have crucial effects on microstructures and properties. We demonstrate that polyurethane dielectric elastomer filled with titanium dioxide functionalized graphene, fabricated as a flexible micro-actuator, displays evident electric stimulus response and electric field induced strain. The hydrophilicity and wettability of graphene can be greatly enhanced by decorating nano-TiO 2 onto graphene, which causes the improved interface interactions between fillers and polymers. Higher dielectric constant, less loss modulus, elevated breakdown strength, and better electric stimulation responses of the novel titanium dioxide functionalized graphene–polyurethane dielectric elastomer composite are achieved due to enhanced filler–matrix interface. The maximum electric induced thickness strain of this titanium dioxide functionalized graphene–polyurethane dielectric elastomer composite is 72.4% at 38.7 V/μm, which is 1.8 times of the electric induced strain of graphene–polyurethane composite. [ABSTRACT FROM AUTHOR]

The electromechanical property of a diaphragm type actuator comprising a copper phthalocyanine oligomer noncovalent functionalized graphene-polyurethane dielectric elastomer (CuPc-RGO@PU) composite is described. The composite film had a dielectric constant of 102 with a dielectric loss of 0.13 at 3.0 wt% CuPc-RGO filler and 1k Hz. The composite film had a loss modulus of 195 MPa with a loss tangent of 0.4 at glass-transition temperature. At 37 MV/m, the electric field induced strain of CuPc-RGO@PU is more than 2.8 and 2.0 times higher than that of CuPc@PU and RGO@PU. The nanocomposites thus seem to be attractive for Micro-Electro-Mechanical System applications. [ABSTRACT FROM PUBLISHER]

Abstract: Poly(methyl methacrylate)-functionalized graphene/polyurethane (MG–PU) dielectric elastomer composites were synthesized. MG was prepared by atom transfer radical polymerization (ATRP) and used as conducting filler. The microstructure of MG and MG–PU was characterized by SEM, TEM and XRD. The thermal degradation, mechanical, dielectric and electromechanical properties were investigated. The three-dimensional (3D) electric field induced displacement and strain of dielectric elastomer surface was observed and measured for the first time. Comparing with pure PU elastomer, the dielectric properties and electric field induced strain performance of MG–PU dielectric elastomer composites were significantly improved. The 1.50wt% MG–PU film had high relative permittivity and electric field induced strain of 28.21 and 32.8%, respectively. [Copyright &y& Elsevier]