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• Series of porous spinel gallate nanospheres are prepared by solvothermal method. • The as-obtained porous spinel gallate nanospheres are composed of nanoparticles. • The porous CdGa 2 O 4 exhibits remarkable formaldehyde sensing performance. • The sensor based on CdGa 2 O 4 responds and recovers ultra-fast to formaldehyde. Spinel metal oxides, prepared at high temperature, have shown excellent gas sensing properties among metal oxide sensing materials. Herein, a series of porous spinel gallate nanospheres, including CdGa 2 O 4 , NiGa 2 O 4 , CoGa 2 O 4 , CuGa 2 O 4 , ZnGa 2 O 4 , and MgGa 2 O 4 were prepared by solvothermal method and followed low temperature calcination. XRD, SEM, XPS and N 2 adsorption-desorption have been carried out to determine their structure, morphology, chemical state and surface area, respectively. These nanospheres are all composed of tiny nanoparticles, giving meso-porous characters. Furthermore, the sensor based on CdGa 2 O 4 exhibits excellent formaldehyde sensing performance, including good selectivity, short response time, and excellent stability at the low working temperature of 120 °C. [ABSTRACT FROM AUTHOR]

The development of recyclable photocatalysts with enhanced photo-induced charge separation and efficient visible light utilization is imperative for antibiotic pollutants removal in aqueous environment. Herein, a Z-scheme Fe 3 O 4 /BiOCl/BiOI heterojunction photocatalyst was constructed using a facile solvothermal method on the basis of BiOCl/BiOI composites. A series of characterization methods were employed to analyze the microstructure, morphology, optical property and chemical composition of as-prepared ternary Fe 3 O 4 /BiOCl/BiOI composite. Field emission scanning electron microscope (FESEM) and transmission electron microscope (TEM) analysis revealed that Fe 3 O 4 nanoparticles were well loaded on the surface of BiOCl/BiOI microspheres. The main active species of Fe 3 O 4 /BiOCl/BiOI during photocatalysis were confirmed by radical trapping experiments, which indicated the formation of Z-scheme heterojunction. Compared to pure BiOCl and BiOI, Fe 3 O 4 /BiOCl/BiOI nanocomposite exhibited significantly improved photocatalytic performance toward tetracycline (TC) degradation (89%, 80 min). Furthermore, the photocatalytic activity of Fe 3 O 4 /BiOCl/BiOI remained at a high level after five cycles, which suggested that the ternary composite possessed good stability and reusability. Such superior photocatalytic activity of Fe 3 O 4 /BiOCl/BiOI was mainly attributed to the suitable band structure and construction of Z-scheme heterojunction, resulting in the enhanced light utilization and migration rate of charge carriers. In addition, Obviously, the ternary composite revealed a potential prospect in the practical application of photocatalytic degradation due to its good magnetic recovery performance and minimal environmental impact. [Display omitted] • The ternary composite (Fe 3 O 4 /BiOCl/BiOI) with magnetic property was synthesized by a facile solvothermal method. • The Z-scheme heterojunction for efficient charge separation was constructed. • Fe 3 O 4 /BiOCl/BiOI possessed superior photocatalytic performance with excellent stability and recyclability. [ABSTRACT FROM AUTHOR]

Highlights: [•] The luminescence intensity of coating (LMC) is inverse ratio to the porosity. [•] The phase composition has influence on LMC. [•] The appearance of new cracks can be monitored by LMC. [ABSTRACT FROM AUTHOR]

By chemical substitutions with Ba2+ and La3+ at A-site in PbHfO 3 -based ceramics, an ultrahigh energy storage efficiency of 91% and high energy density of 7.3 J cm−3 are achieved simultaneously at 290 kV cm−1 in Pb 0.925 Ba 0.045 La 0.03 (Hf 0.6 Sn 0.4) 0.9925 O 3 ceramics. [Display omitted] Near-zero remanent polarization, high breakdown electric field, high saturation polarization and low electrical hysteresis are necessary conditions for antiferroelectric ceramics to obtain excellent energy storage performance. Here, Pb 0.925 Ba x La 0.075−x (Hf 0.6 Sn 0.4) 0.98125+x/4 O 3 lead-based antiferroelectric ceramics were prepared by a rolling process. The composition modulations of Ba and La are beneficial to adjust the phase switching field, improve the saturation polarization and reduce the electrical hysteresis, leading to an enhanced energy storage performance. Simultaneously, the Pb 0.925 Ba 0.045 La 0.03 (Hf 0.6 Sn 0.4) 0.9925 O 3 ceramic exhibited a high energy storage density of 7.3 J cm−3 and an energy storage efficiency of 91%, revealing that this composition is an outstanding candidate in pulsed energy storage application and lays a foundation for further study on the energy storage performances of PbHfO 3 -based antiferroelectric ceramics. [ABSTRACT FROM AUTHOR]

• x wt %-BT/P(VDF-HFP) films were prepared by topochemical microcrystal conversion process and solution casting process. • The composite films exhibit a high breakdown strength of 480 MV/m and the energy density of 19.5 J/cm³. • The excellent cycle life stability of discharge energy density has been achieved in 1.0 wt %-BT/P(VDF-HFP) composite films. Polymer-based dielectric films are considered as most promising materials for pulsed power capacitors due to their ultra-high power density and current density, fast discharging speed, excellent cycle lifetime and so on. However, the relatively low energy density and efficiency limit their applications in modern electronics and electrical power systems. Here we demonstrate a remarkable improvement in the breakdown strength and energy density of [111]c-BaTiO 3 (BT) textured ceramic platelets synthesized in a poly(vinylidene fluoride-hexafluoropropylene) (P(VDF-HFP)) matrix. The breakdown strength of 1.0 wt% BT/P(VDF-HFP) composite films is 130 MV/m higher than that of pristine poly(vinylidene fluoride-hexafluoropropylene) films. The highest energy density of 19.5 J/cm³ and discharged energy density of 10.6 J/cm³ are achieved under an electric field of 480 MV/m in the 1.0 wt % BT/P(VDF-HFP) composite films. Fatigue experimental results show that the energy density and efficiency enhanced with the increase of cycles. This study provides a new paradigm to develop the polymer composites with high breakdown strength and energy density, which has great potential for flexible electrical energy storage applications. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the phase transformation and electrochemical characteristics of the as-cast and annealed La0.75Mg0.25Ni x (x= 3.0, 3.3, 3.5, 3.8) alloys were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), pressure composition isotherm (PCI) and electrochemical measurements. The as-cast alloys were composed of LaNi5, (La,Mg)2Ni7 and (La,Mg)Ni3 phases. Phase transformation of LaNi5 and (La,Mg)Ni3 phases into (La,Mg)2Ni7 phase occurred during annealing treatment, leading to the increase of the (La,Mg)2Ni7 phase and decrease or even depletion of the LaNi5 and (La,Mg)Ni3 phases. The two plateaus observed in P–C isotherms of the as-cast alloys tended to become single and the plateau pressure dropped after the phase transformation by annealing. Electrochemical study showed that for the alloy electrodes with and without annealing treatment, the maximum discharge capacity and HRD initially increased then decreased with x increasing from 3.0 to 3.8. The transformation of the LaNi5 and (La,Mg)Ni3 phases into (La,Mg)2Ni7 phase favored the maximum discharge capacity and cycling stability but suppressed the activation as well as HRD of the La0.75Mg0.25Ni x (x= 3.0, 3.3, 3.5, 3.8) alloy electrodes. The annealing treatment significantly improved the cycling stability of the alloy electrodes by alleviating the pulverization and oxidation degree of the electrode alloys. [Copyright &y& Elsevier]

Abstract: ZnO films with three different microstructures including hexagonal prisms, plates and rose-like twinned crystals were fabricated using chemical bath deposition with different concentration of gelatin. The growth mechanisms of ZnO films were discussed, and the gelatin played a vital role as a polyelectrolyte capping the formation of microstructures. The photoluminescence and Raman properties were found sensitive to the crystal morphologies of ZnO films. Significantly, the photodegradation efficiencies of methylene blue under UV light irradiation in the presence of ZnO films consisted of hexagonal prisms and rose-like twinned crystals were 95% and 96%, respectively. The excellent photocatalytic activities can be ascribed to the high oxygen vacancies concentration and high percentage of polar planes, and this result was important in addressing the origin of high photocatalytic activity. [Copyright &y& Elsevier]

Abstract: The Bi0.86Sm0.14FeO3 (BSFO) and Bi0.86Sm0.14Fe1− x Mn x O3 (BSFMO) (x =0.01, 0.03, 0.05) thin films were deposited on indium tin oxide/glass substrates via a metal organic deposition method. 1at.% Mn doping leads to an evident reduction of the leakage current in BSFO film. More importantly, the Bi0.86Sm0.14Fe0.99Mn0.01O3 film exhibits the lowest coercive field (E c =272kV/cm), the largest remanent polarization (P r =53.6μc/cm2) and the remanent out-of-plane piezoelectric coefficient (d 33 =146pm/V). However, further increase of Mn doping content results in the deterioration of the charge retaining capability and the piezoelectric properties of the films. The negative influence of high Mn doping contents was discussed based on the structure change and the contribution of irreversible movement of non-180° domain walls in the aged films. [Copyright &y& Elsevier]

Abstract: The newly discovered large magnetostriction in antiferromagnetic γ-Mn–Fe alloy is of interest to develop a new kind of ductile and low-cost magnetostrictive materials. This work presents a detailed study on the structures, magnetostrictive, and magnetic properties of a heat-treated Mn42Fe58 alloy by X-ray diffraction (XRD), transmission electronic microscopy (TEM), and superconducting quantum interference device (SQUID) magnetometer. The single γ-phase separates into a mixture containing a face-centered-cubic (fcc) γ-phase, a hexagonal close-packed (hcp) ɛ-phase, and a body-centered-cubic (bcc) α-phase after isothermal heat treatment for 24h at 1100°C. Such phase separation in Mn42Fe58 alloy not only leads to a slight increase in lattice parameter a of the γ-phase and Néel temperature T N, but also results in an obvious enhancement in magnetization due to the presence of ferromagnetic bcc phase. The magnetostrictive performance, however, deteriorates accompanying with the phase separation. [Copyright &y& Elsevier]

Abstract: A visible light active photocatalyst was prepared through boron-doping by using sodium borohydride as boron source. Different from the previous boron-doped titania prepared at high temperature, our preparation was carried out at 55°C under hydrothermal condition. The as-prepared boron-doped titania was characterized by X-ray diffraction, transmission electron microscope, X-ray photoelectron spectroscopy, Raman spectroscope, diffuse reflection spectra and N2 adsorption–desorption measurements. The results showed that diboron trioxide phase appeared in the X-ray diffraction pattern of such photocatalyst. Compared to boron-doped titania synthesized by sol–gel method and pure TiO2, this novel photocatalyst exhibited stronger absorption in the visible region, and it also showed larger surface area. The photocatalytic activity was evaluated for degradation of Reactive Brilliant Red (C.I. Reactive Red 2) and 4-chlorophenol under visible light irradiation, respectively. The trend of photocatalytic activity was as follows: boron-doped titania (hydrothermal method)>boron-doped titania (sol–gel method)>pure titania>Degussa P25. [Copyright &y& Elsevier]

Abstract: We have performed ab initio calculations of the structural, dielectric, and lattice-dynamical properties of the zinc-blende ZnX (X=O, S, Se, Te) using a plane-wave pseudopotential method within the density-functional theory. A linear-response approach to the density-functional theory as implemented in the code ABINIT is used to calculate the Born effective charges, electronic dielectric tensors, phonon frequencies and LO–TO splitting. Compared to the direct approach (or frozen-phonon approach), the linear-response approach has important advantages in that time-consuming supercell calculations are avoided and phonons of arbitrary wave vector can be treated with a cost that is independent of wave vector. The calculated bulk lattice constant values of 4.616Å, 5.392Å, 5.674Å, and 6.226Å for ZnO, ZnS, ZnSe and ZnTe, respectively, were used for phonon calculations. The LO–TO splitting frequencies (in cm−1) at the zone-center (Γ point) are ZnO: LO=517, TO=367; ZnS: LO=333, TO=267; ZnSe: LO=245, 205; ZnTe: LO=188, TO=161. The computed values are in reasonable agreement with experimental data and other calculations. [Copyright &y& Elsevier]

Abstract: A novel magnetically separable composite photocatalyst, titania-coated magnetic activated carbon (TMAC), was prepared by depositing of anatase titania onto the surface of magnetic activated carbon (MAC). The MAC was prepared by a simple route: directly adsorbing of magnetic Fe3O4 nanoparticles onto activated carbon. The prepared samples were characterized by XRD, scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The photocatalytic activity of the samples was determined by degradation of reactive brilliant red X-3B under either UV or visible irradiation, and compared to Degussa P25. The composite photocatalyst can be separated easily from solution by a magnet, its photocatalytic activity in degradation of X-3B also has dramatic enhancement compared to that of P25 titania. The composite photocatalyst can also be reused with a little reduction of its photocatalytic activity. The degradation rates of X-3B were both higher than 80% after six cycles under UV and visible irradiation. [Copyright &y& Elsevier]

• Pt decorated GIO nanofibers have been prepared by electrospinning method. • All Pt-GIO sensors show higher sensitivity to acetone than that of GIO sensor. • The detection limit of the 1.2 at% Pt-GIO sensor is as low as 300 ppb. • The 1.2 at% Pt-GIO sensor can detect acetone in exhaust breath. The concentration of acetone in exhaled breath is an efficient indicator for the diagnosis of diabetes. However, it is difficult to detect acetone in exhaled breath due to the extremely low acetone concentration, rather complex composition and very high humidity. Herein, we report Pt-decorated foam-like Ga-In bimetal oxide nanofibers (Pt-GIO) for trace concentration acetone detection. We found that the Pt-GIO based sensor exhibits enhanced sensing response towards acetone compared with that of Ga-In bimetal oxide (GIO), due to the formation of Schottky contact between Pt and n-type GIO, leading to the increased chemisorbed oxygen. As a result, the Pt-GIO based sensors gives a high response (3.2), short response time (13 s) to 1.8 ppm acetone and very low detection limit (300 ppb). The Pt-GIO sensor also gives good stability and is nearly insensitive to moisture in the range of 40% RH to 95%. These advantages including high response, low detection limit, short response time and high moisture resistance endow Pt-GIO a promising sensing material for acetone detection in exhaled breath. [ABSTRACT FROM AUTHOR]

Abstract: Cathode Li(Ni1/3Co1/3Mn1/3)O2 was prepared by solid-state reaction at low temperatures. Structures of the Li(Ni1/3Co1/3Mn1/3)O2 were investigated as a function of synthesis temperature. The initial discharge capacities are 149, 167, and 161mAh/g for samples synthesized at 600, 700, and 800°C. Except for the sample synthesized at 600°C, the other two samples showed excellent capacity retention at room temperature. Both samples showed better electrochemical properties than those synthesized by co-precipitation and conventional solid-state reaction. The rate capability of the synthesized materials is very good, and the capacity retention is also excellent after 20 cycles. [Copyright &y& Elsevier]

• The phase equilibria of the Cr-Mn-Co ternary system were investigated. • Isothermal sections at 900, 1050, 1150, and 1200 °C were determined. • The σ phase forms a continuous solid solution from Cr-Co side to Cr-Mn side at all temperatures investigated. • The solubility of Co in the (Cr) phase decreases with the increasing Mn content at all temperatures investigated. [Display omitted] The equilibrated microstructures in the Cr-Mn-Co ternary alloys annealed at 900, 1050, 1150, and 1200 °C were studied using X-ray diffraction (XRD) and electron probe micro analyzer (EPMA). The results are summarized as follows: (1) the σ phase has a wide solubility range from Cr-Co side to Cr-Mn side at all temperatures investigated; (2) the σ phase region becomes narrower as the temperature increases from 900 to 1200 ℃; (3) The (αCo) phase has a significant solubility for Cr which decreases with increasing Mn content; (4) the solubility of Co in the (Cr) phase decreases with the increasing Mn content at all temperatures investigated; (5) the solubility of Cr in the (βMn) phase slightly increases as the temperature increases from 900 to 1150 ℃, while the solubility of Co changes hardly. The experimental information obtained from this study is not only useful for the thermodynamic assessment of the Cr-Mn-Co ternary system, but also significant for the alloy design of high entropy alloy. [ABSTRACT FROM AUTHOR]

We report the investigation on the nonlinear optical properties of two typical two-dimensional metal-organic frameworks (2D MOFs) - 2D Cu-MOF and Zn-MOF (c opper/zinc 1,4-benzene dicarboxylate, CuBDC and ZnBDC) using spatial self-phase modulation (SSPM) and spatial cross-phase modulation (SXPM) methods. It is found that 2D Cu-MOF exhibits a large nonlinear optical coefficient n 2 = 5.20 × 10 - 11 m 2 / W a n d χ 3 = 8.24 × 10 − 11 e. s. u . By contrast, no nonlinear optical effect was observed from 2D Zn-MOF under the same condition. The main reason is the Cu center of Cu-MOF has variable valence electrons and a vacant 3 d atom orbit, which can form a conjugated system with organic ligands through the d - π interaction and therefore strengthen the nonlinear optical effect by the delocalization of π electrons. However, the Zn ion of Zn-MOF with fixed valence electrons and fully occupied d orbit makes it hard to produce observable nonlinear optical effect. Furthermore, we demonstrated the ability of 2D Cu-MOF in all-optical spatial light modulation and optical switch based on the principle of SXPM. This work sheds light on the physics of 2D MOFs in all-optical light modulation, providing an insight for rational design of 2D MOFs with high nonlinear optical coefficients in future. • Metal-organic framework materials are rich in research on new energy sources, but there are few researches in photonics. • Experiments show that 2D MOFs are potential candidates for all-optical modulation. • This work provides insights for the rational design of 2D MOFs with high nonlinear optical coefficients in the future. [ABSTRACT FROM AUTHOR]

Additive manufacturing (AM) technology is currently undergoing rapid development in the aerospace field. However, due to the intense cracking susceptibility, additive manufacturing of nickel-based single-crystal (SX) superalloys still presents major challenges. In this paper, the crack-free SX superalloy is fabricated directly using pulsed laser. The microstructure and stress rupture property of the additively manufactured SX superalloy after heat treatment are carefully investigated and compared with conventional cast alloy. The results show that the stress rupture life of the AM sample (66.4 h) is longer than that of the cast sample (59.1 h). This is related to the difference of microstructure between AM and cast samples. AM samples have a finer dendritic structure and lower inter-dendritic segregation, which is conducive to solution strengthening and avoids the formation of TCP phase. Besides, the carbides in the AM sample is finer and evenly distributed, which is conducive to precipitation strengthening; The fine carbides are enveloped within layers of γ′ in the AM samples, which avoids the formation of cracks caused by separation of carbides and the matrix. All of those are beneficial to improve stress rupture properties. • AM sample had fine dendrites, small carbides and homogeneous element distribution. • Dot-like MC Carbides of AM sample was enveloped by γ′ film after heat treatment. • Carbides in the AM sample hardly broke or separated from the γ matrix. [ABSTRACT FROM AUTHOR]

The microstructure and properties of Cu-0.42Cr (wt.%) and Cu-0.45Cr-0.14Ti (wt.%) alloy subjected to cold rolling and aging treatment are investigated through tensile testing, electrical conductivity measurement, scanning electron microscopy, and transmission electron microscopy. Results show that the tensile strength of Cu-0.45Cr-0.14Ti (wt.%) alloy enhances as the degree of deformation increases, but the degree of deformation slightly influences electrical conductivity. When deformation is changed, electrical conductivity is basically unchanged. The good combination of strength and electrical conductivity, which reach 610 MPa and 55.4% IACS, respectively, can be obtained in the Cu-0.45Cr-0.14Ti (wt.%) alloy after 80% cold rolling and aging at 450 °C for 15 min. Ti inhibits the growth of the Cr precipitation phase and enhances the precipitation strengthening effect. Ti mainly exists in the matrix in the form of solute atoms, which do not form a separate lattice structure after aging treatment. • The alloy material is prepared by a process method combining solid solution aging treatment and deformation treatment. • Ti element enhances the effect of age hardening and significantly improves the mechanical properties of the alloy. • Titanium atoms segregate around the Cr phase to slow down the rate of precipitation coarsening. • Ti atoms have never formed a separate lattice structure in the Cu-0.45Cr-0.14Ti (wt.%) alloy. [ABSTRACT FROM AUTHOR]

Mixed transition metal oxides have attracted much attention as anode materials for lithium-ion batteries because of their high theoretical capacity, low cost, and rich redox reaction. In this work, coralline-like FeMnO 3 anode materials are synthesized by a facile co-precipitation method and subsequent sintering in air. The influences of sintering temperature on the microstructure and electrochemical performance of the samples are investigated. The results demonstrated that with the increase of sintering temperature, the phase structure of the products changes from FeMnO 3 /Fe 2 O 3 /Mn 3 O 4 composites at 600 °C to pure phase FeMnO 3 at 1000 °C, accompanied with the size of the primary particle increasing from tens of nanometers to hundreds of nanometers. Discharge/charge performance tests indicated that the sample sintered at 600 °C presents the biggest fluctuation of capacity during cycling, while the sample sintered at 1000 °C gives a rather flat capacity during cycling; moreover, the pure phase FeMnO 3 at 1000 °C possesses the best rate capability among the three samples. For example, the pure phase FeMnO 3 sintered at 1000 °C delivers a specific capacity of 585 mA h g−1 after 290 cycles at the current of 1000 mA g−1; even at the high current density of 5 A g−1, the capacity still retained at 397 mA h g−1. Charge storage mechanism analysis revealed that the pure phase FeMnO 3 sintered at 1000 °C shows obvious pseudocapacitive behavior during the discharge/charge process, which partly account for its superior cycling performance and high-rate capability. • Coralline-like FeMnO 3 are synthesized by a facile co-precipitation method. • The coralline-like FeMnO 3 showed superior lithium storage performance. • The coralline-like FeMnO 3 showed significant pseudocapacitive behavior. • The FeMnO 3 exhibited a lithium diffusion coefficient of 2.42 × 10−15 cm2 s−1. [ABSTRACT FROM AUTHOR]

Solid composite polymer electrolytes have been proposed as high-performance solid electrolytes for next-generation energy storage devices. In particular, UiO-66 with monodispersed size (400 nm) and morphology and outstanding stability was introduced as a functional filler to modify the electrochemical properties of poly(ethylene oxide) (PEO) solid electrolytes with LiClO 4 as the lithium salt. The desired physicochemical properties and electrochemical properties of the electrolyte was improved through microstructure regulation and the intermolecular interactions, as confirmed by X-ray diffraction, differential scanning calorimetry, optical microscopy and electrochemical characterisation. Owing to the intermolecular interactions, crystallisation of PEO was inhibited, and the ionic conductivity of the solid composite polymer electrolyte increased to 4.8 × 10−5 S cm−1 at 25 °C. Electrochemical stable window and lithium ion transference number (t +) were also observably enhanced. The assembled LiFePO 4 /PEO-LiClO 4 -UiO-66/Li solid-state lithium batteries exhibited excellent cycling and C-rate performances. The initial discharge capacity reached to 160 mAh g−1, and superior cycle stability with a capacity retention ratio of 83% after 200 cycles at 1C current and 80 °C was achieved. The discharge capacity at 5C was improved by 232%. This work provides new insights into boosting the performances of solid composite polymer electrolytes through intermolecular interactions. Image 1 • An ionic conductivity as high as 4.8 × 10−5 S cm−1 at 25 °C was obtained in the PEO-LiClO 4 -UiO-66 solid polymer electrolyte. • The high-performance of the solid composite polymer electrolyte was achieved by intermolecular interaction regulation. • The assembled all solid-sate lithium batteries give high initial discharge capacity and superior cycle stability. [ABSTRACT FROM AUTHOR]

As a promising candidate for next generation thermoelectric material, SnSe has attracted extensive attentions due to its intrinsic ultralow thermal conductivity and adjustable electrical transport properties. However, unavailability of Sn-rich crystal leaves a gap in the Sn-deficient, stoichiometric, and Sn-rich series to study the effects of point defects and bonding nature evolution on thermal transport properties in SnSe compound. Also, historic references recorded contradicting electrical transport properties in polycrystalline Te-doped SnSe samples. This study shifted the research object from polycrystalline sample to single crystal to avoid the disturbance of grain boundary scattering and texture on the effects of Te doping. Vast off-stoichiometric Sn-rich Te-doped SnSe crystals were obtained by a self-flux method. The evolution of phase structure and Sn/Se atomic ratio were recorded and correlated. Our results confirmed that the Te atoms are incorporated in the Se sub-lattice, and have the potential to change the cation-anion atomic ratio in Sn-rich crystals. Crystal Sn 1 · 17 Se 0 · 97 Te 0.027 with low concentration of Te shows rather robust thermodynamic properties, while crystal Sn 1 · 10 Se 0 · 88 Te 0.115 is unstable and prone to decompose above 297 °C. Te incorporation and aroused defects are capable of decreasing the hole concentration as other donor dopants, at least at low doping level. Te doping has the potential to change both the band gap and the band structure, and may lead to convergence of multiple valence bands. An increase of thermal conductivity with increase of cation-anion atomic ratio Sn/(Se + Te) was recorded in Te-doped crystals, along with much lower thermal conductivity compared with the pristine one. The results indicates that the excess Sn in Sn-rich samples may cause a change in the bonding nature between cross-plane Sn–Se slabs and makes the material behaves less layer-like and shows more three dimensional thermal transport characterization as in Br-doped SnSe crystals. • Te-doped vast off-stoichiometric SnSe crystals were obtained by self-flux method. • The evolution of phase structure and Sn/Se atomic ratio were recorded and correlated. • Te acts as donor in p -type Sn-rich samples, at least at low doping concentration. • Excess Sn may change the bonding nature between cross-plane Sn–Se slabs. • Te doped SnSe shows more 3D transport characterization as in Br-doped samples. [ABSTRACT FROM AUTHOR]

Direct Z-scheme Bi 3 TaO 7 –CdS semiconductor materials were synthesized via hydrothermal method. The activity of the composites was investigated by the ciprofloxacin (CIP) degradation under visible light irradiation. Bi 3 TaO 7 –CdS composite catalysts all exhibited enhanced photocatalytic performances compared to both single photocatalysts (Bi 3 TaO 7 and CdS). The characteristics of the morphology and structure, the photoelectric properties and the composition of chemical elements of these samples have been studied extensively. Besides, capture experiments demonstrated that superoxide radical and hole worked together for the CIP degradation. The optimal catalyst exhibited stable CIP degradation activity in four cycles repeating experiments. Finally, a possible Z-scheme charge migration mechanism was proposed for the Bi 3 TaO 7 –CdS composite photocatalysts. Three possible pathways were proposed for the CIP degradation based on the detected intermediates by LC/MS. This work provided a feasible idea for the further research of Z-scheme photocatalysts for the emerging contaminants degradation. • CdS/bismuth tantalate composite photocatalysts were synthesized for the first time. • The charge transfer followed Z-scheme mechanism. • The photocatalyst exhibited enhanced performance for CIP degradation of ciprofloxacin compared to Bi 3 TaO 7 and CdS. • The mechanism for the enhanced activity was discussed deeply. • The degradation pathways were deduced based on the detected intermediates. [ABSTRACT FROM AUTHOR]

Constructing heterojunction to achieve efficient charge separation and transfer is a significant way to enhance photocatalytic activity. Herein, a novel ternary Bi 2 O 2 CO 3 –Bi 2 O 2 (OH)NO 3 /g-C 3 N 4 (labeled as BOC-BON/CN) heterojunction photocatalyst was successfully synthesized by ion exchange reaction under hydrothermal conditions. The products were characterized by various analytical methods, including X-ray diffraction (XRD), Fourier transform-infrared spectrometer (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray spectrometer (SEM), UV–vis reflectance spectra (UV–vis DRS), photoluminescence (PL), photocurrent response and electrochemical impedance spectroscopy (EIS). Heterojunction formation mechanism and photocatalytic degradation mechanism were discussed in detail. The prepared BOC-BON/CN heterojunction exhibited excellent Rhodamine B (RhB) photodegradation rate of 0.0476 min−1 under visible light, which was 3.55 times of the pristine g-C 3 N 4 (0.0134 min−1). The significant increase in photodegradation rate was attributable to the heterojunction structure, which promotes the separation of photogenerated charges. Bi 2 O 2 (OH)NO 3 played an essential role as electron accelerator in the charge transfer process. The internal electric field of Bi 2 O 2 (OH)NO 3 accelerates the directed transfer of electron from g-C 3 N 4 to Bi 2 O 2 CO 3. This work extends the study of g–C 3 N 4 –based photocatalytic systems and demonstrates Bi 2 O 2 (OH)NO 3 as a promising cocatalyst. Image 1 • A novel Bi 2 O 2 CO 3 –Bi 2 O 2 (OH)NO 3 /g-C 3 N 4 (BOC-BON/CN) heterojunction was fabricated. • BOC-BON/CN exhibited excellent photocatalytic degradation of RhB under visible light. • The heterojunction structure promoted the separation of photogenerated charges. • The internal electric field of Bi 2 O 2 (OH)NO 3 accelerated the electron transfer from g-C 3 N 4 to Bi 2 O 2 CO 3. [ABSTRACT FROM AUTHOR]

LaFeO 3 /Bi 3 NbO 7 p-n heterojunction photocatalysts were prepared successfully through an in-situ growth method. The phase structure, optical property, morphology and microstructures of the obtained samples were studied by X-Ray diffractometer (XRD), Ultraviolet–visible absorption spectrum (UV–vis DRS), photoluminescence (PL) spectroscopy, transmission electron microscope (TEM), high resolution transmission electron microscope (HRTEM) and scanning electron microscope (SEM). The visible light responsive photocatalytic activity of as-obtained samples were investigated by the photo-reduction of Cr (Ⅵ). The effects of preparation conditions (proportion of BNO/LFO and temperature) on the activity were studied. Results showed that the as-obtained BNO-LFO-200-5 composite behaved the best photocatalytic activity (with rate constant of 0.0212 min−1) among all the obtained samples. The rate constant was about 42.4-times and 17.7-times as that of pristine BNO (0.0005 min−1) and LFO (0.0012 min−1), respectively. The enhanced photocatalytic property of the as-prepare LaFeO 3 /Bi 3 NbO 7 composites can be ascribed to the formation of p-n junction between BNO and LFO, which significantly increased the separation efficiency of photo-excited electron-holes. • A novel LaFeO 3 –Bi 3 NbO 7 p-n heterojunction photocatalyst was prepared for the first time. • The composites exhibited significantly enhanced activity for Cr (Ⅵ) photocatalytic reduction. • The heterojunctions promote the photo-generated carriers transmission and separation. [ABSTRACT FROM AUTHOR]

In the present work, the phase equilibria of the Nb-Ni-Ru system at 1100 °C were investigated via a combination of triple diffusion and equilibrated alloys. The samples were examined by X-ray diffraction and electron probe microanalysis. Three new ternary compounds, namely, τ 1 (Nb 5 Ni 13 Ru 2), τ 2 (Nb(Ni 1-x Ru x) 3 , 0.17 ≤ x ≤ 0.32) and τ 3 (Nb(Ni 1-x Ru x) 3 , 0.34 ≤ x ≤ 0.67), were discovered. The isothermal section of the Nb-Ni-Ru ternary system at 1100 °C consists of 10 single-phase regions, 20 two-phase regions, and 11 three-phase regions. The homogeneity ranges for phases in this system were established. In addition, the phases of the Nb-Ru binary system at 1100 °C were discussed, and the existence of compounds NbRu and NbRu 2 was confirmed. The NbRu 3 phase was not identified, but it should be the solid solution of Nb in Ru. Image 1 • The isothermal section of the Nb-Ni-Ru ternary system was constructed at 1100 °C. • Three new ternary compounds were discovered. • The homogeneity ranges for the phases in this system were established. • The phases of Nb-Ru binary system was discussed at 1100 °C. [ABSTRACT FROM AUTHOR]

Nickel-based Single Crystal (SX) superalloys have an excellent creep ductility and thermal fatigue resistance at elevated temperatures. But SX structure is difficult to be manufactured under the demand of increasing operating temperature and complex shapes. In this work, the feasibility of manufacturing Nickel-based SX-superalloys by selective laser melting (SLM) was investigated theoretically and experimentally. Firstly, the solidification conditions including temperature field, thermal gradient and solidification speed of the SLMed multi-track samples were calculated by an established finite element model to judge the theoretical feasibility based on the columnar to equiaxed transition (CET). Then, the single-track, triple-track and cuboid samples on a single-crystal SRR99 substrate were deposited to judge the experimental feasibility and explore their grain growth mechanism during SLM. The results showed that CET can be avoided during the whole process of SLM. The unidirectional SRR99 SX structure with a height of 2 mm can be successfully obtained by SLM. On horizontal section, the microstructures can be divided into [001] orientation zone, [010] orientation zone and overlapping zone with a typical secondary dendrite structure. On vertical section, the columnar dendritic structure along the dominant thermal gradient direction is present. The primary dendrite spacing of the SLMed samples (∼1–2 μm) is more than two orders of magnitude lower than that of the cast one (∼320 μm). So, SLM technology possesses the capacity to manufacture SX superalloy. When the deposited height reaches 6 mm, the misorientation angle is about 25° and a crack initiates. Finally, the grain growth mechanism of the SLMed SRR99 single-crystal superalloy was proposed based on the local thermal gradient, the existing well-aligned crystallographic orientation and the preferential grain growth direction. • Solidification conditions of the SLMed samples were calculated by a finite element model. • Columnar to equiaxed transition can be avoided during the whole process of SLM. • The single-crystal alloy with a height of 2 mm can be obtained by SLM. • The grain growth mechanism of the single-crystal superalloy was proposed. [ABSTRACT FROM AUTHOR]

Developing highly efficient and earth-abundant electrocatalysts for water oxidation is highly desirable for sustainable energy conversion applications. In this work, we designed and constructed a novel integrated ternary hybrid composed of CoO/Co 3 O 4 (CoO x) nanoparticles supported on CoMoO 4 nanorods (CoO x /CoMoO 4) through a hydrothermal treatment of ZIF-67/CoMoO 4 followed by a thermal annealing. Benefiting from the enlarged surface areas, more active sites and fast charge transfer kinetics resulted from the interface between CoO x and CMO, the CoO x /CMO electrocatalyst manifests the excellent oxygen evolution reaction (OER) catalytic performance with a low overpotential of 253 mV at the current density of 10 mA cm−2 and high long-term durability, which is superior to those of most previously reported Co- or Mo-based oxides electrocatalysts. This work not only provides a highly efficient catalyst for OER but also sheds light on the fabrication of ternary Co-based hybrid electrocatalyst by using ZIF-67 as a precursor. Image 1 Novel ZIF 67-derived CoO/Co 3 O 4 (CoO x) nanoparticles supported on CoMoO 4 nanorods (CoO x /CoMoO 4) is developed, which exhibiting excellent oxygen evolution reactioncatalytic performance with a very low overpotential of 253 mV at the current density of 10 mA cm−2 and high long-term durability. • Novel ternary CoO/Co 3 O 4 /CoMoO 4 heterostructure electrocatalyst was synthesized. • This ternary electrocatalyst showed highly efficient OER activity and long-term durability. • The synergistic effect among the multicomponents contributes to the high activity. [ABSTRACT FROM AUTHOR]

Porous carbons have recently drawn extensive attention in energy conversion and storage devices. Boosting energy densities of carbon family is still a challenge due to their limited surface area and accessible active sites. In this work, porous carbons with hierarchically structures were prepared from natural Juncus effuses (CJE) and homogeneous MnO 2 layer was successfully incorporated on their surfaces without changing their original porous structure. The CJE/MnO 2 composite showed large specific capacitance (283 F/g at 1 A/g), which was on account of high specific surface area (1283 m2/g) and abundant active sites for pseudocapacitance, particularly, resulted from the introduction of MnO 2. Significantly, the assembled symmetric supercapacitor from CJE/MnO 2 in Na 2 SO 4 aqueous electrolyte delivered high energy/power densities (19.13 Wh/kg at 225 W/kg and 13.73 Wh/kg at 8984 W/kg) and good cyclic performance (86.2% capacitance retention over 5000 cycles at 10.0 A/g). These results demonstrate the CJE/MnO 2 composite can be a potential candidate for supercapacitors. • The surfaces of porous carbons from Juncus effuses are functioned. • Oxygen-containing functional groups facilitate the formation of MnO 2 layer. • Prepared CJE/MnO 2 composites show high specific surface area and capacitance. • The supercapacitor from CJE/MnO 2 delivers excellent energy-power output. [ABSTRACT FROM AUTHOR]

Though fluoride is a necessity for human body, excessive intake probably leads to irreversible damages such as dental fluorosis, skeletal fluorosis and lesions of the endocrine glands, thyroid and liver. Herein boron nitride nanosheets (BNNSs) and a series of Al-modified BNNSs (BNNSs-Al-X) with different Al amounts were first prepared to remove superfluous fluoride in aqueous solution. The modified Al was proved to be amorphous Al 2 O 3 on the surface of BNNSs. Batch adsorption results show that both BNNSs and BNNSs-Al-2, which fits pseudo-second-order model well, have high adsorption rate for fluoride. The maximum adsorption capacity calculated by Langmuir model is 50.510 mg/g for BNNSs-Al-2, which is better than vast majority of reported adsorbents. The excellent adsorption capacity of BNNSs-Al-2 could be attributed to the synergy of porous BNNSs and amorphous Al 2 O 3. Primary BNNSs can adsorb fluoride mainly by physical interaction, while chemical adsorption is predominant on the Al-modified BNNSs, which can be deduced from the fitted model and corresponding parameters. All of the above results prove that BNNSs-Al-2, as a promising adsorbent, can play an important role for removal of fluoride in water. In this work, the excellent adsorption properties of Al-modified boron nitride nanosheets (BNNSs) for fluoride were studied systematically for the first time. It can be deduced that Al-modified BNNSs is a promising adsorbent for removal fluoride pollutants from aqueous solution. Image 1 • Excessive intake of fluoride can lead to irreversible damages for human body. • The adsorption of F¯ on BNNSs and Al-modified BNNSs were first investigated. • Both BNNSs and BNNSs-Al-2 have rapid adsorption rate for fluoride. • The maximum adsorption capacity can reach up to 50.510 mg/g for BNNSs-Al-2. • The synergy of porous BNNSs and amorphous Al 2 O 3 enhance the adsorption capacity. [ABSTRACT FROM AUTHOR]

Abstract The Fe 3 O 4 /Fe/C catalyst for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) was prepared using a facile microwave sintering method. The Fe 3 O 4 /Fe/C electrode showed excellent electro catalytic ability on both ORR and OER in alkaline medium. The phase was characterised by X-ray diffraction (XRD). The current density of the Fe/C electrode was 147 mA cm−2 at −0.2 V (vs. Hg/HgO) and 97 mA cm−2 at 0.7 V (vs. Hg/HgO) in 6 mol L−1 KOH electrolyte at room temperature. The mechanism of ORR and OER was explored by the AC impedance. Highlights • The Fe 3 O 4 /Fe/C catalyst was prepared using a facile microwave sintering method. • The Fe 3 O 4 /Fe/C electrode showed excellent catalytic ability towards ORR and OER. • The mechanism of ORR and OER was explored by the AC impedance. [ABSTRACT FROM AUTHOR]

Green synthesis of antibacterial metal oxide nanoparticles is attractive for develop novel antibacterial agents. In this study, probiotic strain Lactobacillus plantarum ZDY2013 fermentation liquid (LFL) was utilized for the synthesis of zinc oxide nanoparticles (called as LFL-ZnO) via an ultrasound-microwave-facilitated procedure. SEM and TEM show the synthesized LFL-ZnO with a spherical morphology that are surrounded by LFL. Zeta potential and hydrodynamic sizes were − 25.533 ± 0.205 mV and 537.5 nm by dynamic light scattering (DLS) analyzer, respectively. X-ray diffraction (XRD) results revealed the hexagonal wurtzite structure of LFL-ZnO with a crystallite size of 41 nm. Fourier transform infrared (FTIR) spectrum and thermal gravimetric (TG) curve showed the structure differences between H-ZnO (synthesized by ddH 2 O instead of LFL) and LFL-ZnO. In addition, LFL-ZnO significantly inhibited the growth of methicillin-resistant Staphylococcus aureus (MRSA) with MIC = 100 μg/mL. The possible antibacterial mechanisms may be attributed to LFL-ZnO release a high concentration of Zn2+ inducing the destruction of bacterial cell integrity resulting in the leakage of protein and reducing sugars. Meanwhile, CLSM results demonstrate the generation of reactive oxygen species (ROS) by LFL-ZnO is another important antibacterial mechanism. The synthesized LFL-ZnO has broad potential to be developed in pharmaceutics as an effective antimicrobial nanomaterial. [Display omitted] • Probiotic strain Lactobacillus plantarum ZDY2013 fermentation liquid (LFL) were utilized for the synthesis of LFL-ZnO. • The LFL-ZnO performs an excellent antibacterial activity against MRSA, and the MIC is 100 μg/mL. • The possible antibacterial mechanisms had been investigated. [ABSTRACT FROM AUTHOR]

A novel plate-like BaFe 12 O 19 @Fe 3 O 4 core-shell composite was successfully synthesized by a hydrothermal method. The phase structure and morphology of as-prepared composite was characterized by XRD, SEM and TEM. The results show that uniform Fe 3 O 4 microspheres with a diameter of about 10 nm were generated as the shell of plate-like BaFe 12 O 19 grains. The static magnetic properties and electromagnetic parameters in the microwave range were measured using a vibrating sample magnetometer and a vector network analyzer, respectively. The obtained BaFe 12 O 19 @Fe 3 O 4 composite exhibits a saturation magnetization of 43 emu/g and a coercivity of 224 Oe at room temperature. A minimum reflection loss of −33.6 dB was observed at 11.6 GHz with a thickness of 2.5 mm in the frequency range of 2–18 GHz, indicating the excellent microwave absorption performances of the novel composite. This improvement in microwave absorption can mainly be attributed to the enhanced magnetic properties due to the exchange coupling effect between the hard magnetic phase (BaFe 12 O 19 ) and the soft magnetic phase (Fe 3 O 4 ). [ABSTRACT FROM AUTHOR]

To solve the poor conductivity of the anode materials for lithium-ion batteries (LIBs) and enhance the lithium-ion transportation, silver-incorporated Fe 2 O 3 -C (Fe 2 O 3 -C-Ag) porous microcubes were fabricated through polydopamine reduction of AgNO 3 and subsequently high temperature carbonization process using the prussian blue as template. Interestingly, polydopamine not only served as reducing agent for Ag + but also as carbon source in this work, which avoid adding additional reduction agent and high temperature, resulting in a simple and mild reduction condition. When Fe 2 O 3 -C-Ag microcubes were performed as anode materials for lithium-ion batteries (LIBs), the hybrid materials behaved pretty electrochemical properties. The introduction of noble metal (Ag) and carbon to transition metal oxides was an innovative method to form anode materials for lithium-ion batteries (LIBs), which can effectively increase the conductivity of the electrode materials as well as inhibit the volume expansion during cycling. With 10% (wt%) Ag nanoparticles coating in the hybrid composites, the Fe 2 O 3 -C-Ag-10 microcubes exhibit good reversible capacities and pretty cyclic performance (858 mAh g −1 after 200 cycles at 100 mA g −1 ). This novel approach can provide a potential idea to design advanced anode materials for LIBs. [ABSTRACT FROM AUTHOR]

In this work, magnetic nanoparticles (MNPs) Fe 3 O 4 /CeO 2 synthesized by the method of impregnation oxidation-precipitation were used as the heterogeneous catalyst for the degradation of Pantoprazole. Response surface methodology based on central composite design was used to investigate the individual and the interactive effects of three process parameters on the Pantoprazole degradation, i.e. the initial pH of the solution, the dosage of H 2 O 2 and the initial concentration of Pantoprazole. Under the optimal conditions of pH 3.3, H 2 O 2 30.0 mM, Pantoprazole 20.0 mg L −1 , catalyst 2.0 g L −1 and 35 °C, the degradation percentage of Pantoprazole was 98.0% within 120 min. The obtained results agreed well with the modeling prediction ( R 2 = 0.9924, and Adj- R 2 = 0.9889), and the degradation reaction well followed the first-order kinetic with R 2 = 0.9986. According to the results of the iron leaching and the effects of the radical scavengers and the intermediates determination, a possible pathway of Pantoprazole degradation was proposed based on ·OH mechanism. [ABSTRACT FROM AUTHOR]

One of the current key issues in the photocatalysis is to obtain the band alignment of coupled semiconductor experimentally, which is the most significant aspect for understanding the efficient photocatalytic activity precisely. In this article, a BiVO 4 /BiOI{001} heterojunction was detected by the transmission electron microscopy (TEM). The results of electrochemical impedance spectroscopy (EIS) reveal that a higher efficiency of charge immigration across the electrode/electrolyte interface for the BiVO 4 /BiOI{001}. In addition, the electron lifetime was investigated by the Bode phase plots, which are responsible for the observed photocatalytic behaviors. As a result, the photocatalytic activities for rhodamine B (RhB) degradation and iodine ion oxidation are remarkably increased compared to the individual BiVO 4 and BiOI{001}. In fact, a direct band alignment in the BiVO 4 /BiOI{001} does not give well a logical interpreting on its photocatalytic behavior. However, through the valence-band offset formula, we demonstrated the exact band alignment of corresponding components in the BiVO 4 /BiOI{001}. This band alignment was further confirmed by the PL spectra, which CM2 with photo-oxidation (Mn 2+ ) is red shift and CM2 with photo-reduction (Ag + ) is blue shift compared with CM2. [ABSTRACT FROM AUTHOR]

Hierarchical Cu-Ni-Pt dendrites were successfully prepared by a two-step electrodeposition route in air at room temperature. Firstly, Cu-Ni dendrites were deposited on the ITO glass at the deposition current of 10 mA for 5 min. Then, hierarchical Cu-Ni-Pt dendrites were obtained from the H 2 PtCl 6 solution, employing the ITO glass with Cu-Ni dendrites as the working electrode. The deposition processes were carried out at 10 mA for 1–5 min. The phase and morphology of the as-prepared products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), (high-resolution) transmission electron microscopy (HRTEM/TEM), and X-rays photoelectron spectrometry (XPS). It was found that the as-deposited hierarchical Cu-Ni-Pt dendrites exhibited highly electrocatalytic activity and superior long-term cycle stability toward methanol oxidation in 0.5 M H 2 SO 4 solution; and excellent catalytic activities for the reduction of 4-nitrophenol to 4-aminophenol in excess NaBH 4 solution. [ABSTRACT FROM AUTHOR]

A MoS 2 /CNT nanocomposite containing three-dimensional (3D) flower-like MoS 2 nanospheres and interconnected carbon nanotubes (CNTs) has been successfully synthesized by using MoO 3 and KSCN as reactants and deionized water as solvent with the presence of CNTs through a facile one-step hydrothermal method. The nanocomposite was applied as an electrode material for the supercapacitors with excellent energy storage performance. The structure and morphology of the nanocomposite were characterized by scanning electron microscopy and transmission electron microscopy, which show that MoS 2 nanospheres are about 300 nm in diameter and interconnected by CNTs. The special capacity of the nanocomposites can reach 74.05 F/g at a high current density of 2 A/g, which is higher than those of the flower-like MoS 2 and MoS 2 nanosheets at the same current density. Furthermore, the specific capacitance of the MoS 2 /CNT nanocomposite still maintains 80.8% of initial capacitance over 1000 cycles at the current density of 2 A/g. The excellent electrochemical performance and long cycle life of the nanocomposite are attributed to the synergetic effect between CNTs and ultrathin MoS 2 nanosheets grown vertically on the flower-like MoS 2 . [ABSTRACT FROM AUTHOR]

A novel solvothermal chemical route has been developed to synthesize Cu–Sb–S compound nanocrystals in a controllable manner. Cu 3 SbS 4 and CuSbS 2 nanocrystals can be selectively prepared by modifying the reaction temperature. The temperature dependent release of antimony from potassium antimonyl tartrate trihydrate faciliated the selective synthesis of Cu 3 SbS 4 and CuSbS 2 . The bandgap is 1.0 eV for Cu 3 SbS 4 nanocrystals and 1.45 eV for CuSbS 2 nanocrystals. Semiconductors of Cu–Sb–S compounds with such band gaps are desirable for solar cell applications. The Cu 3 SbS 4 and CuSbS 2 nanocrystals both showed obvious photo-electric response, indicating their potential application as an active layer in thin-film solar cells. [ABSTRACT FROM AUTHOR]

A La 0.59 Nd 0.14 Mg 0.27 Ni 3.3 alloy with 72 wt% Gd 2 Co 7 -type (3R-A 2 B 7 ) and 28 wt% Ce 2 Ni 7 -type (2H-A 2 B 7 ) phases is prepared by induction melting followed by the annealing at 1148 K. Upon further increasing the annealing temperature to 1248 K, the 3R-A 2 B 7 phase transforms into the 2H-A 2 B 7 phase, forming an alloy with a 97 wt% 2H-A 2 B 7 phase and a 3 wt% 3R-A 2 B 7 phase. Electrochemical measurement shows that the discharge capacity retention of the alloy electrode at the 100 th cycle increases from 88.5% to 92.4% as the 2H-A 2 B 7 phase increases from 28 wt% to 97 wt%. Compared to the 3R-A 2 B 7 phase, the 2H-A 2 B 7 phase shows a stronger ability to resist amorphousiation during dehydrogenation and has better structural stability. Therefore, the transformation from the 3R-A 2 B 7 phase to the 2H-A 2 B 7 phase stabilizes the structure of the alloy against amorphization and oxidation, thus improving the cyclic stability of the alloy. Electrochemical pressure–composition ( P–C ) isotherms contain two discharge plateaus; the higher plateau corresponds to the 3R-A 2 B 7 phase and the lower one is associated with the 2H-A 2 B 7 phase. As the 2H-A 2 B 7 phase increases, the high-rate dischargeability of the alloy electrodes increases from 56.8% to 66.3%. [ABSTRACT FROM AUTHOR]

A non-carbonaceous titanium-based materials of Na 2 Ti 3 O 7 have been considered as an attractive anode material for sodium ion battery (SIBs), due to its low charge potential and high energy density. However, the selection of preferred sodium salts in liquid electrolyte is still a challenge to improve battery performance. Herein, the compatibility of Na 2 Ti 3 O 7 @C anode material with sodium perchlorate (NaClO 4)-based and sodium trifluoromethyl sulfonate (NaCF 3 SO 3)-based electrolytes are studied, respectively. The results show that solid electrolyte interphase (SEI) film formed by NaCF 3 SO 3 -based electrolyte is thin, compact and uniform, which can effectively reduce the transmission energy barrier of Na+. Different from that, the SEI film derived in NaClO 4 -based electrolyte contains more Na 2 CO 3 and NaF, caused by the continuous decomposition of NaClO 4 salt in carbonate solvent. It makes the SEI film thicker and the interface impedance larger, which results in the decline of battery cycle performance. In addition, more sulfur-containing compounds with good sodium conductivity and stability are generated due to the decomposed of NaCF 3 SO 3 salt in carbonate solvent, which improves interfacial transport performance of materials, and inhibits the increase of the SEI film thickness and thus improves the cycling and rate performance of batteries. This study provides a reference method for designing advanced SIBs. [Display omitted] • NaCF 3 SO 3 improves the initial coulomb efficiency of the material. • NaClO 4 promotes the formation of a thick but soft SEI film containing more Na 2 CO 3. • A thin but hard SEI film derived NaCF 3 SO 3 contains more stable inorganic species. • NaCF 3 SO 3 -based electrolyte is more conducive to performance promotion of Na 2 Ti 3 O 7 @C. • Direct visualization information of the formation of SEI film is provided. [ABSTRACT FROM AUTHOR]

In this paper, TiO 2 nanorod arrays were prepared via seed-free and seed-assisted method and denoted as TA-SF and TA-SA respectively. TA-SF exhibited higher photoelectrochemical performance due to decreased resistance, prolonged electron lifetime obtained from electrochemical impedance spectra (EIS). A novel photo-reduction method was then employed to deposit and manipulate the loading amount of Au decoration. The Au/TA-SF photoanodes were then used in photoelectrochemical cells and the influences of the Au loading amount on the PEC performances were studied in detail. Due to the surface plasmon resonance (SPR) effect of Au nanoparticle, charge transfer resistance was decreased and Au/TA-SF hybrid arrays exhibited improved photocurrent density compared with TA-SF arrays. Typically, Au/TA-SF exhibited higher photocurrent density of 1.1 mA/cm 2 , which is much higher than that of Au/TA-SA. [ABSTRACT FROM AUTHOR]

In this work, Cu(In 1−x Ga x )Se 2 (CIGS) absorber layer is fabricated via radio-frequency sputtering of standard quaternary CuIn 0.75 Ga 0.25 Se 2 target. In order to achieve the desired Cu-poor absorber film stoichiometry, which is crucial for the device performance, indium is supplied simultaneously with the CIGS deposition by direct current sputtering of indium target for the first time. The influences of sputtering power on composition, structure of the CIGS absorber films and the performances of related solar cells are systematically investigated. The precursor absorber film exhibits uniform and compact surface morphology without peeling and cracking. After selenized in a tube-type rapid thermal processing system under a Se atmosphere, the CIGS absorber layer possesses columnar grains with preferred (112) orientation. Photoelectric measurements of the most efficient device with CdS buffer and ZnO window layer reveals a short-circuit current of 32.02 mA/cm 2 , an open-circuit voltage of 532 mV, and a fill factor of 60.5 under standard conditions. The efficiency of up to 10.29% on 0.35 cm 2 area without antireflection coating has been achieved. Our new sputtering route shows great potential for practical applications of thin film CIGS solar cells with in-line sputtering processes. [ABSTRACT FROM AUTHOR]

Antimony selenosulfide (Sb 2 (S,Se) 3), an emerging photovoltaic material, exhibits excellent photovoltaic performance, low toxicity, and high stability with a broad development prospects. High-efficiency Sb 2 (S,Se) 3 solar cells use Spiro-OMeTAD as a hole-transport layer for a long time, which poses serious cost, stability and safety issues. This study applies molybdenum trioxide layer prepared by electron-beam evaporation as an alternative to Spiro-OMeTAD, improving cell stability and reducing the manufacturing cost. Device performance characterization and analysis reveals the significant role of MoO 3 in enhancing charge collection, increasing built-in voltage, and inhibiting carrier recombination. Finally, Sb 2 (S,Se) 3 solar cells with a photoelectric conversion efficiency value of 7.20% were obtained based on the FTO/CdS/Sb 2 (S,Se) 3 /MoO 3 /Au structure. This work could lay the foundation for the further development of stable and efficient fully inorganic Sb 2 (S,Se) 3 solar cells. [Display omitted] • Stable electron beam evaporation-prepared MoO 3 hole-transport layer for Sb 2 (S,Se) 3 solar cells for the first time. • MoO 3 layer can effectively enhance the hole mobility and inhibit the carrier recombination of the device. • Sb 2 (S,Se) 3 with MoO 3 HTL achieved a 7.2 % efficiency based on a high current density of 16.53 mA cm-2. [ABSTRACT FROM AUTHOR]

The development of active nonprecious-metal and heteroatom-doped materials is critical for the oxygen evolution reaction (OER). Herein, asphaltene-derived carbon-coated Fe- and N-doped hierarchical hollow porous carbon microtubes were prepared through feasible freeze-drying and carbonization/activation strategies. Cotton with a fibrous morphology acted as a soft template and carbon precursor, while asphaltene with easy graphitization properties was utilized to stabilize the structure of microtubes and accelerate the charge conductivity. Meanwhile, Fe- and N-doping changed the electronic structure of carbon and increased the number of active sites. In particular, the optimum sample displayed excellent OER activity with a lower overpotential of 261.4 mV at 10 mA/cm2 and Tafel slope of 94.60 mV/dec under alkaline conditions. Moreover, the catalyst demonstrated excellent long-term durability with a 10% attenuation rate after continuous operation for 50 h by the chronoamperometry method at a constant potential of 1.5 V. This work provides a strategy for the effective resource utilization of biomass and asphaltene to prepare highly efficient OER electrocatalysts. The iron and nitrogen anchored hierarchical hollow porous carbon microtubes with high degree of graphitization were synthesized using cotton and asphaltene as precursors and exhibited a low overpotential, small Tafel slope and remarkable long-term durability as electrocatalyst towards oxygen evolution reaction. [Display omitted] • Iron and nitrogen anchored hierarchical hollow porous carbon microtubes werederived from cotton and asphaltene. • Cotton provided the resultant carbon microtubes skeleton and a mass transport path for OER. • Graphitc carbon from asphaltene accelerate the charge conductivity. • Synergistic effect of hierarchical hollow porous tubular and doping of Fe and N atoms resulted in excellent OER activity. • Fe3N site played an important role for high OER activity. [ABSTRACT FROM AUTHOR]

In this study, Fe 2 O 3 with oxygen vacancies (OVs) introduced by Ti doping is partially wrapped by reduced graphene oxide (rGO), and then grown directly on carbon cloth (CC) to obtain a self-supported electrode with hierarchical structures (Ti-Fe 2 O 3 @rGO/CC). Compared with Fe 2 O 3 nanosheets, Ti-doped Fe 2 O 3 nanosheets show better lithium storage performance because the existence of OVs can not only promote faster charge transfer kinetics but also help to maintain the integrity of electrode structure and improve the electrochemical activity. Especially, the rGO sheets are partially wrapped on Ti-Fe 2 O 3 , inhibiting the agglomeration of components and shortening the diffusion distance of Li+, to obtain better cycle stability. Moreover, it can also provide a buffer to alleviate the volume expansion, avoid the excessive growth of SEI film, and ensure that OVs can maximize their advantages under deep discharge conditions. The Ti-Fe 2 O 3 @rGO/CC electrode delivers a high capacity of 1193 mAh g−1 (3.245 mAh cm−2) at 200 mA g−1, showing great potential as an anode material for lithium-ion batteries. [Display omitted] • Fe 2 O 3 with oxygen vacancies was partially wrapped by rGO and loaded on carbon cloth as self-supported electrode. • The OVs promote fast charge transfer, maintain the electrode integrity and improve the electrochemical activity. • The rGO inhibits excessive growth of SEI film and ensures the OVs to maximize their advantage under deep discharge. • The electrode delivers high Coulomb efficiency and high reversible capacity. [ABSTRACT FROM AUTHOR]

Quasi two-dimensional perovskite solar cells (Q-2D PSCs) has attracted the attention of many researchers in recent years due to improved stability compared to their three-dimensional (3D) counterparts. However, the insulation of organic cation could hinder charge transfer between the octahedral sheets, thereby decreasing photoelectric performance of Q-2D PSCs. Here, the study of the synergistic effect of MACl and GuSCN on crystal orientation and quality of films based on the 4F‐PEA 2 MA 4 Pb 5 I 16 perovskite are reported. The Q-2D perovskite film exhibits more vertical orientation growth and lower trap-state density with the effect of dual additive. As a result, the device obtained a power conversion efficiency (PCE) of 15.05% for planar p-i-n solar cell using the Q-2D perovskite film with dual additive, which retained an average of 85% of their initial PCEs after 300 h in an ambient environment with humidity of 50 ± 10%. This result indicates that the use of dual additive MACl and GuSCN is an effective way to adjust the crystal orientation and quality of perovskite films, which are key factors to influence the performance of Q-2D PSCs. • The Q-2D perovskite film 4F‐PEA 2 MA 4 Pb 5 I 16 with dual additives (MACl and GaSCN) was prepared for the first time. • With the synergistic effect, the high-quality Q-2D perovskite film with more vertical orientation was obtained. • There was a larger concentration window of GaSCN additive in the presence of MACl due to their synergistic effect. • Compared with the Q-2D PSCs without additive, the PCE of Q-2D PSCs based on dual additives increased by 1.76 times. [ABSTRACT FROM AUTHOR]

Rare earth–Mg–Ni-based alloys with superlattice structures are novel anode materials for nickel metal hydride batteries, wherein A 5 B 19 -type alloys have been regarded as the replacement of the current commercialized A 2 B 7 -type alloys due to the superior discharge ability at high rates and cycling stability. However, it is still a challenge to further improve the hydrogen storage properties of the A 5 B 19 -type alloys in a low-cost approach. Herein, we select low-cost Mn and Fe elements to substitute Ni to further reduce the cost of an A 5 B 19 -type La 0.72 Y 0.13 Mg 0.15 Ni 3.70 Al 0.15 alloy and focus on their effects on the alloy's structure and hydrogen storage properties. Results show that the La 0.72 Y 0.13 Mg 0.15 Ni 3.65 Al 0.15 Fe 0.05 alloy features increased intrinsic gas-solid hydrogen storage ability of 1.44 wt% and hydrogen absorption enthalpy change of −22.9 kJ mol–1, which have been altered by 0.21 wt% and 7.3 kJ mol–1 in contrast to the La 0.72 Y 0.13 Mg 0.15 Ni 3.70 Al 0.15 alloy, respectively. Furthermore, the Fe substitution benefits capacity retention during electrochemical cycling compared to Mn, which maintains 87.5% and 62.4% after cycling 100 and 500 times. The Mn substitution results in superior rate capability compared to the alloy containing Fe. The work provides guidance for designing hydrogen storage alloys with superlattice structures to improve the electrochemical performance. • Pr 5 Co 19 -type alloys with low cost Mn and Fe substituted Ni are obtained. • Effect of Mn and Fe substituted Ni on hydrogen storage properties is clarified. • Fe substituted Ni increases hydrogen storage capacity from 1.23 wt% to 1.44 wt%. • Fe substitution rises the capacity retention from 52.6% to 62.4% at the 500th cycle. • Mn substitution optimizes the discharge ability at high rates. [ABSTRACT FROM AUTHOR]

Introducing defects into Pd-based metallene has been shown to significantly enhance its electrocatalytic performance. In this study, we embedded a new type of atomic-scale cavities into the basal plane of PdMo bimetallene (c-PdMo) through precise etching. These cavities introduced tensile strain and increased the generalized coordination number (CN ̅), resulting in superior performance in formate oxidation reaction (FOR) and methanol oxidation reaction (MOR), with mass activities of 5.01 mA μ g NM − 1 and 5.38 mA μ g NM − 1 , respectively. Notably, a two-electrode system comprising commercial Pt/C and c-PdMo coated on carbon paper achieved cell voltages of only 0.517 V and 0.362 V at 10 mA cm−2 for FOR and MOR, respectively. Additionally, density functional theory calculations revealed that the deliberate lattice tensile strain and enhanced coordination numbers reduced the D-band center of defective PdMo, which improved OH adsorption and reduced CO adsorption, thus optimizing FOR and MOR catalysis on the surface of c-PdMo bimetallene. [Display omitted] • PdMo bimetallene with atomic-scale cavities (c-PdMo) was prepared via etching. • Atomic-scale cavities can regulate coordination number and strain of bimetallene. • Atomic-scale cavities can modulate the surface adsorption energies of CO and OH. • c-PdMo exhibited highly-efficient mass activity for FOR and MOR. [ABSTRACT FROM AUTHOR]

The forming of Li-Bi alloy can build a lithiophilic protective layer on the lithium anode, however, it is found that the lithium dendrites trend to grow on the surface of bismuth-rich solid electrolyte interphase (SEI) and there is an exfoliation of SEI from substrate caused by de-alloying process at a large current density. The failure cause of the bismuth-rich SEI is considered as the inadequate Li-ionic conductivity of the passivation layer, which cannot facilitate the lithium deposition on the substrate. Then the components with high Li-ionic conductivities such as Li 3 N, LiF and Li 2 S are introduced into the SEI to adjust the characteristic of the bismuth-rich layer by the addition of LiNO 3 , Bi 2 S 3 and FEC. All of them enhance the SEI's performances effectively and LiNO 3 presents the best. With the addition of LiNO 3 , the SEI thickness is decreased and Li-ionic conductivity is enhanced while Li 3 N became one of the major components of the layer. Utilizing the improved bismuth-rich protective layer the Li/Li symmetric cell presents an overpotential at ∼10 mV in a long cycle over ∼1700 h at 4 mA cm−2, and the LiFePO 4 /Li cell with the cathode loading of ∼10 mg cm−2 exhibits a capacity retention rate 72.1% in 400 cycles. This work provides a new SEI design strategy for lithium metal anode operating at high current density and an inspiration for improving other functional interfacial layers in lithium batteries. • Lithium bismuth alloy and dendrites trend to dealloy and grow on the SEI at high current density. • Additives enhancing Li-ionic conductivities are introduced to adjust the bismuth-rich layer's components. • Lithium nitrate addition make Li 3 N a major component of the layer and significantly enhances SEI electrochemical properties. [ABSTRACT FROM AUTHOR]

• Y 3 LiGeS 7 and Y 3 Cd 0.5 GeS 7 were successfully synthesized for the first time. • Optical performances of title crystals were systematically investigated. • All of them exhibit large SHG responses with requisite phase-matching behavior. • SHG-density and dipole moment calculation analyze the origin of NLO effect. [Display omitted] Combination of multiple structural groups was developed as one effective method for regulating material property and exploring new nonlinear optical (NLO) crystals. For that reason, four Ln 3 MGeS 7 (Y 3 LiGeS 7 , Y 3 Cd 0.5 GeS 7 , Gd 3 Cd 0.5 GeS 7 and Sm 3 Zn 0.5 GeS 7) crystals with various structural motifs were successfully synthesized and systematically investigated. Note that Y 3 LiGeS 7 and Y 3 Cd 0.5 GeS 7 were firstly synthesized so far. Performance test shows that Ln 3 MGeS 7 compounds exhibit the variable optical bandgaps (1.62–2.33 eV) and good second harmonic generation (SHG) responses (0.7–1.1 × commercial AgGaS 2) with requisite phase-matching behavior, which agree well with the theoretical results (Y 3 LiGeS 7 : Δ n = 0.058 and d 33 = 19.97 pm/V; Y 3 Cd 0.5 GeS 7 : Δ n = 0.055 and d 33 = 20.6 pm/V) and introduction of MIIB (Zn, Cd) atoms into crystal structure is conducive to enlarge the SHG effect. SHG density and dipole-moment calculations indicate that their SHG effects are originated from the major contribution on LnS n units with moderate effect of GeS 4 and MIIBS 6 (Zn, Cd) ligands. Therefore, selecting appropriate functional motifs (LnS n and MIIB) into crystal structure can promote the enhancement of NLO property and further realize the rational design of new promising infrared NLO materials. [ABSTRACT FROM AUTHOR]