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Si has attracted more attention as an ideal anode for next-generation Li-ion batteries (LIBs), due to its large theoretical capacity and low de-lithiation voltage. However, extreme volume change (about 300%) and low electronic conductivity severely hinder its practical application. Herein, to overcome these problems, via the electrospinning and pyrolysis processes, Si nanoparticles are embedded in porous N-doped carbon fibers (Si/P-NCFs) and interwoven into a flexible film. The binder-free and flexible Si/P-NCFs can significantly enhance the Li-ion storage capacity (1386 mAh g−1 after 100 cycles at 0.1 A g–1), cycling stability (942 mAh g−1 over 1000 cycles at 1 A g−1), as well as rate capability (381 mAh g−1 at 10 A g−1). These improvements are ascribed to the spatial confinement of carbon fibers and buffering effect of porous structure, which synergistically prevent the harm caused by the volume change. Additionally, porous N-doped carbon networks and binder-free structure can significantly enhance electron/ion conductivities. This work demonstrates an effective design to address the volume change and low electronic conductivity of Si towards advanced flexible Si-based anodes, as well as exhibits promising potential in practical use. [Display omitted] • Si are embedded in porous N-doped carbon fibers and interwoven into a flexible film. • Confinement of carbon fibers and porous structure can buffer volume change of Si. • Carbon fibers, N-doping, and porous structure can facilitate charges/ions transfer. • The binder-free and flexible Si/P-NCFs exhibits improved Li-ion storage properties. [ABSTRACT FROM AUTHOR]

The development of non-noble metal electrocatalysts for oxygen evolution reaction (OER) has attracted widespread attention in the field of energy. Herein, we report a facile in-situ etching method to convert commercial stainless steel felt (SSF) into NiFe 2 O 4 octahedral nanoparticles as an efficient and robust OER electrode. This preparation method of NiFe 2 O 4 is different from the conventional ones, both nickel and iron elements come from the substrate itself without extra addition of precursors, as well as NiFe 2 O 4 octahedral nanoparticles are self-grown directly on the substrate without binder. The treated SSF shows good water oxidation properties with low overpotential, small Tafel slope, and durable stability at 500 mA cm−2 for 200 h. Moreover, the effect of NaNO 3 in the etchant is studied carefully, which plays the function of removal of chromium and promoting the formation of octahedral nanoparticles, resulting in the enhancement of conductivity and catalytic activity. This study presents a new preparation method for producing NiFe 2 O 4 octahedral nanoparticles with the characteristic of low cost, simple process, wide raw material sources, and favorable OER activity, which demonstrates a good application prospect in the field of large-scale hydrogen production. [Display omitted] • Low cost NiFe 2 O 4 octahedral nanoparticles are prepared by a facile in-situ etching of stainless steel felt. • The prepared NiFe 2 O 4 octahedral nanoparticles exhibit high catalytic activity and good long-term stability for OER. • NaNO 3 is proved to have the function of removing Cr and promoting the formation of octahedral nanoparticles. [ABSTRACT FROM AUTHOR]

• High pressure increases the solid solubility of Al 2 O 3 in ZnO. • The thermoelectric properties of the sample are explained by the given band gap model under high pressure. • The whole synthesis procedure last only for 30 min. • High pressure can induce rich defects. ZnO has excellent electrical properties such as high conductivity (σ) and Seebeck coefficient (S) that are important for its thermoelectric properties and have provided the basis for obtaining improved ZnO-based thermoelectric materials by doping. In particular, the most representative Al-doped ZnO (AZO) has excellent thermoelectric performance. Although the Al doping is beneficial for reducing the lattice thermal conductivity of ZnO, the solubility of Al 2 O 3 in ZnO is limited and excessive doping of Al gives rise to the generation of a large amount of the ZnAl 2 O 4 secondary phase that limits the further improvement of the electrical properties. Thus, it is crucial to develop approaches to reduce thermal conductivity while still maintaining high electrical properties. In this work, high pressure and high temperature (HPHT) synthesis was used to adjust the ZnO optical band gap by modifying the lattice parameters of ZnO, and thereby improving the electrical properties of the sample. It was found that the optimal doping content for the samples synthesized at high pressure is different from that of the samples synthesized at normal pressure, providing a new approach for the further improvement of the thermoelectric properties of ZnO. Additionally, high pressure can promote grain refinement that is conducive to the generation of the multi-scale hierarchical structure of the sample that introduces a variety of phonon scattering mechanisms to reduce the thermal conductivity while maintaining a high power factor. The Zn 0.96 Al 0.04 O material obtained by sintering at a pressure of 3 GPa and a temperature of 1053 K for 30 min reached the highest power factor (7.8 µW cm−1 K−2) and the highest zT (0.16) at 973 K. [ABSTRACT FROM AUTHOR]

Abstract: Transparent hybrid conducting films were prepared by dodecylbenzene sulfonic acid-doped polyaniline (DBSA-PANI) and 3-glycidoxypropyltrimethoxysilane (GPTMS) through a sol–gel process. DBSA-PANI was synthesized via emulsion polymerization, and inorganic acid (nitric or sulfuric acid) was added to adjust the structure of the emulsion system and obtain the higher conductivity of polyaniline. When nitric acid was used in the emulsion system, structure of the hybrid films became more stable and sheet resistance of the hybrid films was lower. Visible light transmittance of the hybrid films was over 75%. Various properties of the hybrid material were analyzed by the infrared spectra (IR), UV–visible absorption spectra, thermogravimetric analysis (TG) and digital four-point probe meter. [Copyright &y& Elsevier]

Abstract: Schiff base synthesized by APTES (3-aminopropyltriethoxysilane) and salicylaldehyde was used as the ligand for coordination with Eu3+ ions. It was covalently attached with meso-structured monoliths via post-synthetic method. The assembly materials were characterized by infrared spectra, CHN elemental analysis, BET analysis and luminescence measurement. The results showed that assembly material had much weaker emission intensity of the ligand, which indicated that energy transfer from ligand to Eu3+ in the assembly became more efficient than that in the neat complex. Additionally, Eu-assembly sample exhibited much longer lifetime and higher emission quantum efficiency of Eu3+ than those of the neat complex. [Copyright &y& Elsevier]

Abstract: The formation of a Fe43.7Co7.3Cr14.7Mo12.6C15.5B4.3Y1.9 bulk metallic glass (BMG) was attempted in low vacuum environment and in air using commercial raw materials. The glass forming ability of the Fe-based alloys was studied by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and differential thermal analyzer (DTA). It was found that cylindric rods with diameters ranging from 10mm to 5mm could be successfully fabricated by copper-mold casting in the pressures from 1.5Pa to 105 Pa (105 Pa=1atm). All BMGs exhibit a distinct glass transition and wide supercooled liquid region. The preparation condition seems not significantly affected by the thermodynamic parameters of BMG, such as supercooled liquid region, glass transition temperature and melting process. The oxygen content of the alloys prepared in different vacuum conditions was measured by a LECO oxygen analyzer, which revealed that the oxygen content was less than 100ppm for all BMGs prepared, even in air. The good glass forming ability and excellent oxidation resistance for the present Fe-based alloy are discussed. [Copyright &y& Elsevier]

Abstract: A Zr55.9Cu18.6Ta8Ni10Al7.5 bulk metallic glass (BMG) composite with an amorphous matrix reinforced by micro-scale particles of Ta-rich solid solution was prepared by copper-mold casting. The crystallization kinetics of the BMG composite was investigated under isothermal conditions by differential scanning calorimetry (DSC) and was modeled by the Johnson–Mehl–Avrami equation. It was found that the crystallization process follows three distinct stages with different Avrami exponents. The average Avrami component was about 2.5 at the initial and final stages, implying a mechanism of diffusion-controlled three-dimensional growth with a constant nucleation rate. However, the Avrami exponent was higher than 4 in the middle stage, indicating that the crystallization involved a transient nucleation process with an increasing nucleation rate. The different mechanisms in various stages of crystallization were tentatively discussed from a structural point of view. [Copyright &y& Elsevier]

Here, the thermal and electrical properties of Al doped ZnO were synergistically improved by using high temperature and high pressure (HPHT) technology. HPHT treatment to modulate its crystal structure and microstructure. We simulated this process using first-principles calculations and finite element analysis. Increasing the synthesis pressure improved the electrical and thermal properties. As the synthesis pressure increased, the band gap decreased, and the electrical properties were improved. HPHT also changed the microstructure, and full-spectrum phonon scattering provided the sample with a relatively low thermal conductivity. The sample synthesized at 4.5 GPa achieved a dimensionless figure of merit (zT) of 0.165 at 973 K. Compared to related literature, the synthesized Al doped ZnO showed better thermoelectric properties than previous achievements at the same temperature, showing that HPHT provides a promising method for improving its thermoelectric performance. • The grain size and band gaps of ZnO were effective optimized. • Partial high pressure features of ZnO have been captured to the ordinary pressure. • The whole synthesis procedure last only for 30 min. • High pressure can induce rich defects which are beneficial for thermal properties. [ABSTRACT FROM AUTHOR]

Mg-based alloys exhibit a good degradation performance in wastewater treatment containing dyes. The degradation performance of as-spun Mg crystalline ribbon, Mg 78 Zn 22 (MZ) semi-amorphous ribbon and Mg 73 Zn 22 Ca 5 (MZC) amorphous ribbon on acidic orange dye (AO II) solution is improved apparently by citric acid (CA) solution immersion. The degradation rate constant k of MZ ribbon after immersing for 1 h reaches 0.084 min−1, showing a much higher degradation efficiency than other immersed ribbons. Compared with the immersed Mg and MZC ribbons, the surface of immersed MZ ribbon has a developed loofah porous structure and an appropriate crystallization. Here, the crystallization induced porous structure is composed of Zn and ZnO, which can generate more nascent hydrogen [H] by transporting Mg atoms to surface and more O 2 • − radical by supplying photo-catalytic ZnO under visible light and then enhance the degradation of AO II dye. This work not only proposes a new method to improve the degradation efficiency of AO II dye by Mg-based alloys, but also provides a new insight into the microstructure and properties of Mg-based alloys. Image 1 • Crystalline, semi-amorphous and amorphous Mg-based ribbons have been melt-spun. • Immersed semi-amorphous ribbon has a high degradation efficiency of AO Ⅱ dye. • Its high efficiency is due to the loofah porous structure on ribbon surface. • ZnO on ribbon surface also has an important contribution to dye degradation. [ABSTRACT FROM AUTHOR]

Due to its enormous development potential, research on perovskite solar cells (PSCs) is progressing rapidly worldwide. Among numerous hole transport materials (HTMs), an organic molecule spiro-OMeTAD emerged victorious. Spiro's application in PSCs is constrained to its weak hole mobility and low conductivity. Here, an inexpensive, ecologically friendly inorganic oxidant iodine pentoxide (I 2 O 5) is used to aid in quick and manageable oxidation of Spiro. I 2 O 5 -modified Spiro as HTM improves the charge carrier transportation. Meanwhile, trap-states density and trap-assisted recombination are decreased. Additionally, the modification adjusts the HTM's energy level to match the perovskite layer properly. As a result, the I 2 O 5 -modified PSC achieves a champion power conversion efficiency of 22.80%, while the pristine device gets an efficiency of 20.65%. [Display omitted] • Iodine pentoxide (I 2 O 5) is introduced to spiro-OMeTAD hole transport layer. • I 2 O 5 -introduction adjusts Spiro oxidation rate and increase carrier concentration. • I 2 O 5 -modification decreases defect density and trap-assisted recombination. • I 2 O 5 -treated PSC achieves an efficiency of 22.80%, pristine device gets 20.65%. [ABSTRACT FROM AUTHOR]

Understanding corrosion behavior under hydrostatic pressure is crucial for the design of materials for deep-sea industrial applications. In this work, the corrosion behavior of a Fe 48 Mo 14 Cr 15 Y 2 C 15 B 6 amorphous coating was examined under high hydrostatic pressure (80 atm), and compared to that at atmospheric pressure (1 atm). The results from immersion and potentiodynamic polarization tests indicate that the general corrosion rate of the coating increased at 80 atm with respect to that at 1 atm, yet the localized corrosion resistance did not change much. However, the stability of passive films at 80-atm is declined compared to that at 1-atm, which is attributed to the lower compactness and higher density of point defects in the passive film at high hydrostatic pressure. Finally, TEM observations reveal that the passive film formed at 80 atm is much thicker (nearly 3 times) than that formed at 1 atm due to a faster dissolution rate of metals and diffusion rate of ions under high hydrostatic pressure, which have a compensation for the decrease of stability and compactness of the passive film, such that the good localized corrosion resistance of the amorphous coating is reserved at high hydrostatic pressure. This study sheds light on the dynamics of passive film formed on amorphous metals and will also be helpful for designing corrosion-resistant materials for deep-sea applications. [ABSTRACT FROM AUTHOR]

The electrical properties of the perovskite oxide thermoelectric material SrTiO 3 (STO) should be improved in order to realize its thermoelectric application due to its intrinsic insulation characteristics. The bulk STO materials usually optimize their electrical properties by annealing in reducing environment after synthesis. However, this method inevitably leads to the gradient distribution of oxygen defect concentration in materials. In this study, the combination of High Temperature and High Pressure (HPHT) method is used, and Ti powder is added to optimize the electrical properties of STO materials. HPHT provides a closed synthesis environment. In addition, with the strong oxygen-capturing ability of Ti at high temperature, the semi-conductivity of materials is performed. The thermoelectric properties of the synthesized materials under HPHT are studied using XRD, XPS, SEM, and TEM. The properties and micro-morphology of the synthesized samples with different Ti contents are investigated. The results show that, with the increase of the Ti content, the oxygen defect concentration increases and the electrical properties are significantly improved. Simultaneously, the sample synthesized using the HPHT method changes its micro-morphology and reduces the thermal conductivity of the material. The increase of oxygen vacancy concentration can also effectively reduce the thermal conductivity. Under the collaborative optimization of HPHT while adding Ti, the maximum obtained zT value at 20 wt% addition is 0.19 @ 973 K. The density functional theory calculation also shows that, compared with pure STO, the band gap of STO with oxygen vacancy decreases, which increases the conductivity. Therefore, a high pressure and the addition of Ti powder provide a fast, simple and efficient method for preparing oxygen-deficient perovskite oxide materials, which is of great significance for improving its thermoelectric properties. • The introduction of oxygen vacancies effectively improves the electrical properties. • High pressure-induced micromorphological changes and generated oxygen vacancies reduce thermal conductivity. • The whole synthesis procedure last only for 30 min • Theoretical calculations show that oxygen vacancies can significantly improve the electrothermal transport properties of perovskite-structured materials. [ABSTRACT FROM AUTHOR]

An experimental investigation was conducted to understand the influence of hydrostatic pressure on phase transition, thermal expansion and barocaloric property of a polycrystalline Ni 54 Mn 23 Ga 23 alloy. Two pressure ranges of 0–1.28 GPa and 0–0.74 GPa were selected for thermal expansion and barocaloric property measurements due to the different test limits of instrumentals. The pressure dependence of fourteen parameters was studied systematically. It was found that the sample experiences a martensitic transformation (MT) near room temperature and the response of MT peak temperature (T M) to pressure is about 15.89 K/GPa. The phase transition strain (λ tr), transformation width (Δ T tr) relative volume change (|Δ V / V |) and maximum adiabatic temperature change (Δ T ad) max increase linearly with pressure and their shifting rates are about 0.071 %/GPa, 7.5 K/GPa, 0.211 %/GPa and 12.2 K/GPa, respectively. Simultaneously, applying hydrostatic pressure can also enhance the barocaloric property of the sample, leading to a large increase in the absolute value of the maximum entropy change (|Δ S | max), the refrigerating capacity (RC) and their reversible values. On cooling, the sensitivities of the reversible RC and its proportion to pressure are around 185.52 J/kg GPa and 16.7 %/GPa, respectively. Finally, the average linear expansion coefficient (α ave) of both martensite and austenite phases keeps unchanged while in the MT region it decreases from -99.84×10–6/K to -86.04×10–6/K with increasing pressure from 0 to 1.28 GPa. These findings indicate that applying hydrostatic pressure can effectively adjust the phase transformation, thermal expansion and barocaloric property of Ni-Mn-Ga alloys, which are meaningful for their application in solid-state refrigeration. • Pressure can effectively adjust phase transformation, thermal expansion and barocaloric property of Ni 54 Mn 23 Ga 23 alloy. • A large response of martensitic transformation (MT) peak temperature to pressure is reported. • The barocaloric property and its reversibility are highly sensitive to pressure. • The average linear expansion coefficient during MT decreases with increasing pressure. [ABSTRACT FROM AUTHOR]

Silicon, as the earth-abundant semiconductor, has low cost and good compatibility with mature complementary metal-oxide-semiconductor technology. Therefore, instead of choosing the proper semiconductor with a specific bandgap energy, hyperdoping technique, which can introduce deep-level dopants and intermediate band into silicon, enable silicon to operate in infrared wavebands. Particularly, the hyperdoped silicon with transition metals, having low ionized impurity scatting, makes silicon a promising infrared detection material. In present work, zinc-hyperdoped silicon is fabricated by femtosecond pulsed laser irradiation. The doping concentration of zinc has exceeded 1019 cm−3, and even reached 1022 cm−3, which is about five orders of magnitude greater than the solid solubility of zinc in crystalline Si. The zinc-hyperdoped silicon shows sub-bandgap absorptance of 87.86 % at 1310 nm. Temperature-dependent Hall effect measurements prove that zinc doping results in acceptor energy level located at 0.520 eV above the valence band maximum. It is worth nothing that, zinc-oxygen related defect state results in donor energy level located at 0.252 eV below the conduction band minimum when lower laser fluence is used, which means the energy level of impurity is altered by the presence of undesignedly doped oxygen atoms, suggesting compound formation between the zinc atoms and oxygen atoms. • The concentration of Zn atoms is about five orders of magnitude greater than the solid solubility of Zn in crystalline Si. • Zn hyperdoping can achieve a nice tradeoff between sub-bandgap absorption and recombination within IB materials. • As deep level dopant, ionizing impurity scattering of Zn atoms has weak impact on the charge carrier transport process. • Zn-hyperdoped Si can extend the operating wavelength to shortwave infrared region. • Zn-hyperdoped Si exhibits dual conductive type that depends on the relative content of Zn and O in hyperdoped layer. [ABSTRACT FROM AUTHOR]

Ni-rich cathode material LiNi 0.6 Co 0.2 Mn 0.2 O 2 with the advantage of relative high capacity, low cost and high safety has been realized mass industrial production. To maximize the electrochemical performance of LiNi 0.6 Co 0.2 Mn 0.2 O 2 , it is highly necessary to gain insight into the inherent laws of precipitation process and precisely control the characterization of secondary and primary particle of precursor. Herein, the evolution of structure, morphology, D 50 , tap density, {010} facts for Ni 0.6 Co 0.2 Mn 0.2 (OH) 2 precursor and the electrochemical performance of corresponding cathode modulated by ammonia during hydroxide precipitation are investigated. The particle size, D 50 , tap density and morphology are charged with the increase of reaction time under different of ammonia concentration. When the feeding time is larger than 32 h, the steady state of the continuous precipitation is reached. The higher amount of ammonia leads to the formation of precursor crystal with higher percentage of (001) plane and cathode with better electrochemical performance. The understanding of the evolution of precursor and electrochemical performance of Ni-rich cathode modulated by ammonia during hydroxide precipitation would provide new a guiding significance for the controllable preparation of other lithium transition metal oxide materials. • Evolution of precursor is modulated by ammonia during hydroxide precipitation. • Steady state of precipitation is reached when feeding time is larger than 32 h. • Higher amount of ammonia enhances the percentage of area for (001) plane. [ABSTRACT FROM AUTHOR]

The catalytic activities of Au 5- x Ag x (x = 0, 1, 2 and 5) alloys for the electro-oxidation of methanol (CH 3 OH) and formic acid (HCOOH), together with their structure and microhardness, are studied in extruded and annealed states. For the electro-oxidation of CH 3 OH, the catalytic activity of Au–Ag alloys increases continually with increasing x ; for HCOOH, the catalytic activity of Au–Ag alloys reaches the maximum as x = 1, indicating that the Ag addition can apparently improve the catalytic activity of Au–Ag alloys. Meanwhile, the catalytic activity of annealed Au for the electro-oxidation of CH 3 OH and HCOOH is lower, but that of annealed Au 3 Ag 2 is higher than the extruded counterpart, indicating that annealing treatment has a complex effect on the catalytic activity of Au–Ag alloys. This complex effect is due to the fact that the changes of texture and twin crystal fraction of Au after annealing are different from those of Au 3 Ag 2. • Ag addition can apparently improve the catalytic activity of Au–Ag alloys. • EBSD data indicate the texture change and the existence of crystal twin. • Catalytic activities of Au–Ag catalysts can be regulated by texture and twin. • Plastic deformation ability of Au–Ag alloy is characterized by the Schmid factor. [ABSTRACT FROM AUTHOR]

Abstract In the present work, phosphate-bonded porous silicon carbide (SiC) ceramics were prepared by using aluminum dihydrogen phosphate as binder. The morphologies, phase composition, microstructures, mechanical strength, porosity and bulk density of the porous ceramics were investigated. It was found that the aluminum dihygrogen phosphate binder bonding method was a novel and low cost process to prepare near net-shape and high strength porous SiC ceramics at low temperature. The bonding mechanism was A type and B type aluminum metaphosphate which formed from aluminum dihygrogen phosphate during heat treatment bonded the SiC particles together to form porous ceramics. With temperature increasing, the phase of B type gradually transformed into A type aluminum metaphosphate, and the transformation was completed at 900 °C. The A type aluminum metaphosphate began to decompose into AlPO 4 and P 2 O 5 when the sintered temperature higher than 908 °C. The flexural strength of the porous SiC ceramics reached the maximum at 900 °C and decreased sharply with temperature increasing. The decomposition of A type aluminum metaphosphate made the strength reduce. The bulk density increased with aluminum dihydrogen phosphate content and decreased with temperature, in contrast, the porosity decreased with increasing binder content and temperature. Highlights • Porous SiC ceramics were prepared at low temperature by phosphate bonding method. • Aluminum dihydrogen phosphate was a new binder for preparing porous SiC ceramics. • Porous SiC ceramics bonded by aluminum dihydrogen phosphate had a lower shrinkage. • Aluminum dihydrogen phosphate bonding method was a near net-shape forming process. [ABSTRACT FROM AUTHOR]

As a new kind family of lead-free Na 0.5 Bi 0.5 TiO 3 (NBT) ceramics, bismuth layer-structured ferroelectrics (BLSFs), Na 0.5 Bi x Ti 3.98 Mg 0.02 O y ( x = 4.48, 4.50, 4.52) were synthesized by a conventional mixed oxide route. Studies have found that the dielectric properties of Na 0.5 Bi 4.5 Ti 4 O 15 can be optimized through changing the Bi content of the ceramics or Mg-doping on Ti-site under different sintering temperatures. X-ray diffraction analysis indicated that the new material was in a single BLSFs phase. The dielectric constant of Mg-doped Na 0.5 Bi 4.5 Ti 3.98 Mg 0.02 O y was improved and dielectric loss of Na 0.5 Bi 4.5 Ti 3.98 Mg 0.02 O y changed slowly under 500 °C with the increased sintering temperature. We found that the dielectric properties of the sample sintered at 1120 °C with the highest permittivity of 1122.5 and the lowest dielectric loss of 0.01 were relatively better than those of the other samples. SEM can be better to explain the results of the dielectric spectrum at different sintering temperatures through grain size mechanics. Z* plots showed that Na 0.5 Bi 4.5 Ti 3.98 Mg 0.02 O y ceramics are a kind of dielectrics. Thus, Na 0.5 Bi x Ti 3.98 Mg 0.02 O y ( x = 4.48, 4.50, 4.52) can be used as high-temperature capacitors and phase shifter with high dielectric constant, low dielectric loss and wide operating temperature range. [ABSTRACT FROM AUTHOR]

Because of its high stability and low cost, titanium oxide is a very promising thermoelectric material. Improvement of its thermoelectric performance is limited by the strong correlations among conductivity, Seebeck coefficient, and thermal conductivity. It is therefore important to optimize at least two of these three parameters. This paper provides a new idea for the synergistic optimization of the conductivity and thermal conductivity of titanium oxide. Under high temperature and high pressure, the elementary substance Ta can reduce TiO 2 to Magnèli phase titanium oxide (mainly Ti 8 O 15), which greatly increases its conductivity. At the same time, the submicron tantalum oxide (Ta 2 O 5) generated during the reaction process can effectively reduce the lattice thermal conductivity and total thermal conductivity, and realize the synergistic optimization of the conductivity and thermal conductivity of the material. The titanium-tantalum-oxygen composite thermoelectric ceramics prepared by the high-pressure and high-temperature (HPHT) method have good thermoelectric and mechanical properties. The maximum zT value of the material at 973 K is 0.176, and its Vickers hardness is 11.14. • The addition of elementary substance Ta achieves the synergistic optimization of the conductivity and thermal conductivity of the sample. • The synthesis time is short, and the process is convenient and rapid. • A titanium-tantalum-oxygen composite thermoelectric material is obtained, which has good thermoelectric and mechanical properties. [ABSTRACT FROM AUTHOR]

The effects of interrupted aging on the microstructure, mechanical properties and corrosion resistance of Al–Cu–Mg–Ag heat-resistant alloy were investigated by hardness tests, tensile tests, exfoliation corrosion (EXCO) tests, transmission electron microscopy (TEM) and electrochemical analysis. Results showed some phases precipitated during the interrupted aging process in Al–Cu–Mg–Ag alloy, which were called secondary precipitations. The precipitations both in the grains and the grain boundaries were refined by interrupted aging. The phases on the grain boundaries of the single-aged sample were distributed discontinuously, whereas those of the interrupted-aged sample were chain-like with a wider precipitation free zone (PFZ) on both sides of the grain boundary. The elongation of Al–Cu–Mg–Ag alloy increased by 37.7% while the tensile and yield strength slightly decreased after interrupted aging. The corrosion resistance of Al–Cu–Mg–Ag alloy was mainly determined by the PFZ with the lowest self-corrosion potential. The coarse and discontinuously distributed precipitations on the grain boundaries of the single-aged sample gave rise to larger efficient PFZ width than that of the interrupted-aged sample, which then lead to wider corrosion passageway and resulted in the better exfoliation corrosion resistance of Al–Cu–Mg–Ag alloy treated by interrupted aging. [ABSTRACT FROM AUTHOR]

A novel method for preparing lead-free Cu nano Bi (CNB) alloy materials by nano Bi powder and shift-speed ball milling (SSBM) flake powder metallurgy was proposed. To improve the mechanical and tribological properties of the alloy materials, the spherical CuSn10 powder was firstly extruded and sheared into flakes by low-speed ball milling (LSBM) in the SSBM system. Meanwhile, the nano Bi powder was evenly dispersed and coated on the CuSn10 flakes. The mechanical alloying between mixed powders and the cold welding of flake CuSn10 flakes containing nano Bi into layered particles were then realized through short-time high-speed ball milling (HSBM) in the SSBM system. While promoting the uniform dispersion of lubricating phase Bi, the surface area of matrix CuSn10 flake was increased so as to achieve better combination of CuSn10 matrix in the material. Results show that the mechanical properties of the CNB material prepared through nano Bi powder and SSBM flake powder metallurgy improved compared with the Cu-Bi material prepared by HSBM. In addition, the antifriction and wear resistance improved by 30% and 80%, respectively. • Lead free Cu-Bi materials were prepared by nano Bi and shift-speed ball milling technology. • Cu-Bi material prepared by nano Bi particles could replace CuPb alloy. • The evolution of Cu-Bi mixed powder during shift-speed ball milling was analyzed. • The mechanism of improving the properties of Cu nano Bi alloy by shift-speed ball milling was analyzed. [ABSTRACT FROM AUTHOR]

• Highly porous carbon nanofibers were prepared via an electrospinning method. • The carbon with hierarchical and entangled structure shows abundant active sites. • The porous carbon displays remarkable reversible capacity toward K ion storage. [Display omitted] Carbonaceous anode materials have been considered as a competitive candidate for the advanced potassium ion batteries (PIBs) owing to their high conductivity, low cost, relatively high theoretical capacity and stability. However, the poor ion transfer kinetics and undesired discharge capacity always limited their practical application. Herein, we reported the highly porous carbon nanofibers (HP-CNFs) prepared by using a facile electrospinning method for efficient K-storage. Due to its highly porous morphology, enlarged interlayer distance, N-doping, and abundant active sites, HP-CNFs can realize the rapid and reversible insertion/deinsertion of large-size K ions. HP-CNFs display reversible capacity of 311.7 mAh g−1 as an anode of PIBs even after 1000 cycles. This excellent electrochemical performance proves the feasibility of using HP-CNFs as a promising anode material for advanced PIBs. [ABSTRACT FROM AUTHOR]

• In situ Ni coated FeS particles were prepared by a simple surface modification method. • Lead-free copper matrix composites were prepared through in situ Ni-coated FeS surface niodification and mechanical alloying. • The in situ Ni-coated FeS improved the interface bonding between FeS and CuSn10 matrix. • The density, hardness and tribological properties of FCB composites were improved. Lead-free FeS/Cu-Bi (FCB) copper matrix composites were prepared by ball milling and in situ Ni-coated FeS surface modification, and their mechanical and tribological properties were studied. Results showed that the hardness of the prepared FCB material increases from 50.5 HRB to 64 HRB, and its density also increases from 5.82 g/cm3 to 6.96 g/cm3. Although FeS surface modification can improve the mechanical properties of the prepared materials, their impact toughness and crushing strength decrease after the mechanical alloying of the mixed powders. However, these two processes have a good synergistic effect on improving the tribological properties of the prepared materials. The friction coefficient and wear rate of the prepared FCB composites were reduced by 29% and 73.2%, respectively. The surface modification and uniform dispersion of the second phase particles in the matrix led to enhancement in the binding energy with the matrix and the mechanical and tribological properties of the materials. [ABSTRACT FROM AUTHOR]

• The disordered rock salt-type LiTiO 2 was prepared by one-step hydrothermal method. • LiTiO 2 was a versatile material for photocatalysts and lithium battery electrodes. • Proper impedance and charge separation efficiency improved photocatalysis. • Helpful diffusion channel and distance made the battery performance excellent. [Display omitted] Disordered rock salt-type LiTiO 2 was successfully synthesized by a simple hydrothermal method. The crystal structure and morphology of samples obtained under different alkali concentrations were characterized. The alkaline solution affected the crystal morphology and growth process. LiTiO 2 synthesized at 180 °С with [OH− = 0.4–3.0 M for 12 h owned high crystallinity and uniform octahedral shape with an axial length of less than 100 nm. TiO 2 underwent hydrolysis into TiO 6 8− octahedral units, which rearranged the cubic intermediate TiO with shared edges. Then, Li ions infiltrated into the TiO lattice to randomly replace Ti ions to generate the cubic LiTiO 2 target. And the moderate alkali concentration could heighten the content of LiTiO 2 and enhance the photodegradative ability of LiTiO 2 to methylene blue. LiTiO 2 was a direct gap semiconductor with a band gap of 3.75 eV. The results of electrochemical properties showed that LiTiO 2 as a lithium-ion battery anode material had high discharge specific capacity, excellent rate performance, good cycle stability and durability. At the current density of 100 mA/g, the largest initial discharge specific capacity of LiTiO 2 was up to 479.9 mA h/g with the initial Coulombic efficiency of 55.7%. These results illustrated that LiTiO 2 is a good multifunctional material. [ABSTRACT FROM AUTHOR]

Preparation of TiAl x O 1.80-x (x = 0.06, 0.04, 0.02) under high temperature and high pressure (HPHT) can adjust the energy band gap and modify the resistivity of the material, and gives rise to special microstructure and morphology that reduce the phonon thermal conductivity. In this work, we sought to obtain improved the thermoelectric performance of oxide materials by adjusting the doping ratio of Al and Ti in TiAl x O 1.80-x. The phase structures of different samples were studied by X-ray diffraction. The morphology characteristics generated by HPHT synthesis were studied by electron microscopy （FSEM, HRTEM）and the thermoelectric properties of TiAl x O 1.80-x (x = 0.06, 0.04, 0.02) were evaluated. It was found that an appropriate Al and Ti doping ratio combined with the use of HPHT synthesis can reduce the resistivity of the sample and inhibit the rapid increase of thermal conductivity with increasing temperature. The best zT value (0.22) was obtained at the temperature of 973 K for the TiAl 0 · 04 O 1.76 sample. • Prepare samples with different Al and Ti doping ratios under high temperature and high pressure. • The typical non-stoichiometric titanium oxide structure obtained at high temperature improves the thermoelectric performance of the sample. • Adjust the doping ratio of different Al and Ti to obtain the best thermoelectric performance of the sample, which is 10% higher than that of the sample prepared under the same conditions. • The effect of the ratio of doping with Al and Ti on the performance of the samples was studied. [ABSTRACT FROM AUTHOR]

Hole transport materials (HTMs) play an important role in perovskite solar cells (PSCs). At present, the most frequent used HTM is spiro-OMeTAD. However, spiro-OMeTAD without dopants have low electrical conductivity and hole mobility. Therefore, the improvement of mobility and conductivity of hole transport layer (HTL) has become a crucial issue. Here, we introduce a dopant, thionyl chloride (SOCl 2), to oxidize spiro-OMeTAD and generate more spiro-OMeTAD+. Under the same conditions, the optimized device doped with SOCl 2 achieves a power conversion efficiency (PCE) of 20.76%, while the pristine one is only 18.13%. The doping of SOCl 2 not only reduces the density of defect states at the interface between perovskite and HTL, but also suppresses the recombination of light-induced carriers. In addition, the stability of the PSCs based on SOCl 2 is greatly improved, which can maintain 90% of the initial PCE for 31 days under ambient conditions. This work provides a simple and feasible strategy for dopant engineering of HTL to achieve efficient PSCs. Image 1 • Thionyl chloride (SOCl 2) is doped to oxidize spiro-OMeTAD and form spiro-OMeTAD+. • The doping reduces the density of defect and the recombination of carriers. • The device doped with SOCl 2 achieves a PCE of 20.76% and excellent stability. • Conversely, the pristine device obtains an efficiency of 18.13%. [ABSTRACT FROM AUTHOR]

Nanostructured WO 3 films prepared by an industry compatible method with large surface area and strong adhesive force to the substrate are highly desired for electrochromic (EC) applications. Here, we report the preparation of a kind of WO 3 nanoisland films on indium-doped tin oxide (ITO)-coated glass substrates by Ag-induced reactive sputtering deposition combined with a post-etching treatment. Our study demonstrates that compared with the bare WO 3 film, the nanoisland film exhibits apparently enhanced EC performance, including high luminous transmittance (92.8%) in a bleached state, high luminous coloration efficiency (126.4 cm2/C), relatively fast color-switching time (7.1 s for coloring and 12.1 s for bleaching), decent long-term cycling stability (2000 cycles) and improved self-bleaching ability. Electrochemical kinetics analysis indicates that such enhanced EC performance relies on large lithium-ion diffusion coefficient (2.37 × 10−10 cm2/s), a good ability of charge storage (10.82 mF/cm2), and low charge-transfer resistance (196 Ω) of the nanoisland microstructure. The results shed light on exploring a novel method to prepare high EC performance WO 3 film. Image 1 • WO 3 nanoisland films can be fabricated by Ag-induced magnetron sputter deposition combined with a post-etching treatment, which significantly increases the contact interface between the electrolyte and materials. • The special nanostructure promotes the electrochromic performance eminently: higher optical transmittance (92.8%), coloration efficiency (126.4 cm2/C) and fast response time (7.1 s for coloring and 12.1 s for bleaching). • The electrochemical performance was analyzed to explain the internal cause relying on large ion diffusion coefficient (2.37 × 10−10 cm2/s), good charge storage (10.82 mF/cm2), and low charge-transfer resistance (196 Ω). [ABSTRACT FROM AUTHOR]