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The entrainment defects generated during the preparation of semi-solid slurries following the rheocasting technique impart poor mechanical and comprehensive properties to the casting. However, the mechanism of formation of these defects in semi-solid slurry has rarely been studied, so the mechanism of the formation of entrainment defects in the semi-solid A356 aluminum alloy be herein reported. The speed of the thermal equilibrium body (TEB) was maintained at 1300 and 2500 rpm where the entrainment defects of slurry were analyzed under conditions of internal cooling thermal equilibrium (ICTE). Results obtained using the SEM and computed tomography revealed the formation of bifilm defects, bubble trails, gas pores, and shrinkage pores in the slurry produced when the speed of rotation was 2500 rpm which resulted in lower elongation. The tensile specimens fabricated at the 2500 rpm speed were worse than those fabricated when the rotational speed was 1300 rpm in the aspect of elongation and reliability of mechanical properties. Results from numerical simulation and water simulation indicated that the phenomenon of surface turbulence promoted the formation of entrainment defects, and the bubbles entrapped inside the slurries could not escape according to the bubble theory floating calculation. • Extensive and dispersed gas pores and shrinkage defects are found in the selected samples fabricated at 2500 rpm, as shown in Fig. 4a and 4b. As Fig. 4c reveals that the shapes and sizes of gas pores and shrinkage defects are clearly different from each other. • Fig. 5 presents a typical bifilm defect with its crack-like characteristics, which form an irregular shape due to its continuous folding, and this feature can be used to distinguish it from the stress-induced crack morphology. • Results from numerical simulation and water simulation indicated that the phenomenon of surface turbulence promoted the formation of entrainment defects, and the bubbles entrapped inside the slurries could not escape according to the bubble theory floating calculation. [ABSTRACT FROM AUTHOR]

Abstract Color-tunable semiconductor quantum dots (QDs) are highly attractive for a wide range of applications including imaging, sensing, and lighting. Herein, we reported a facile synthesis of copper-doped zinc sulfide quantum dots (ZnS:Cu QDs) with tunable emission colors, using a microwave-assisted one-pot reaction. 3-mercaptopropionic acid (MPA) was used as a stabilizer agent and sulfide source for the formation of ZnS:Cu QDs. The photoluminescence of ZnS:Cu QDs showed a clear red-shift as increasing Cu concentration, which can be controlled by microwave irradiation time. As increasing the irradiation time, the emission color (peak) of ZnS:Cu QDs changed from blue (500 nm) to green (540 nm), yellow (580 nm), and to orange-red (595 nm). The obtained ZnS:Cu QDs were highly luminescent, as evidenced by their high quantum yields. The potential utility of ZnS:Cu QDs as a novel lighting source was demonstrated in a near-UV chip-based white light-emitting diode. Highlights • A facile synthesis of Cu doped ZnS QDs via a microwave-assisted one-pot reaction. • Tunable emission colors was highly dependent on the amount of incorporated Cu + dopant. • The potential utility of these QDs was demonstrated in white LED applications. [ABSTRACT FROM AUTHOR]

Abstract Transparent electronic technology has many urgent optoelectronic device applications. A key component of plasmonic materials in conventional semiconductors is the wide band gap of oxide thin films. Although transparent electronic materials have been developed for visible and near-infrared wavelengths, systems incorporating mid-infrared and far-infrared spectra are difficult to achieve. In this study, hydrated magnesium-carbon films, a new type of non-oxide transparent conductive thin films with a magnesium hydroxide structure, were generated using the three-step method. After annealing treatment, larger crystals in the thin films typically exhibited superior film resistivity, with conductivity values of approximately 8.63 × 10−3 Ω m. Due to the free electron concentration was not more than 1020 cm−3, the films demonstrated excellent optical properties, with plasma wavelength values of approximately 8 μm for infrared transmittance above 70%. After annealing, due to the Moss-Burstein (M-B) effect, the visible light transmittance was greater than 85% and the optical bandgap shifted towards the blue region. In addition, the influences of the sputtering power of the carbon target on the properties of hydrated magnesium-carbon film were also discussed in this paper. Graphical abstract Image 1 Highlights • We prepare hydrated magnesium-carbon films using the three-step method. • We analyze the effect of annealing on structural, electrical, and optical features. • Annealing leads to crystal growth, superior film resistivity, and good conductivity. • Films exhibit excellent optical properties, particularly for far-infrared ranges. • The films can replace TCO in the application of optical-electronic devices. [ABSTRACT FROM AUTHOR]

In this work, BiVO 4 films are firstly synthesized, followed by electrodepositing of Cu 2 O to construct BiVO 4 /Cu 2 O heterojunction electrodes for photoelectrochemical water splitting. By regulating the electrodeposition potential, it is possible to control that Cu 2 O is deposited on the surface or inside of BiVO 4 , which enables them n-type or p-type semiconductivity behavior for oxygen and hydrogen evolution reactions, respectively. Due to the built-in electric field of p-n heterojunction and the Co-Pi co-catalyst layer, the anodic photocurrent density of optimized BiVO 4 /Cu 2 O/Co-Pi photoanode reaches 1.97 mA cm−2 at 1.23 V vs. RHE. In the meantime, the deposition of Cu 2 O inside BiVO 4 has reversed the arrangement of the BiVO 4 /Cu 2 O heterogeneous structure. The cathodic photocurrent density of the fabricated BiVO 4 /Cu 2 O-C photocathode shows − 2.9 mA cm−2. Furthermore, the unbiased solar tandem cell is fabricated using BiVO 4 /Cu 2 O-C photocathode and BiVO 4 /Cu 2 O/Co-Pi photoanode, which exhibits 0.1 mA cm−2 in the photoelectrochemical cell without applying any external voltage. [Display omitted] • BiVO4 decorated with Cu2O can be served as photoanodes. • By varying electrodeposition potential, the as-fabricated hybrid BiVO4/Cu2O photoelectrodes also exhibited photocathodes character. • The unique distribution location of Cu2O renders it to form anticipant heterojunctions with opposite conductive types. • The BVO/Cu2O/Co-Pi—BVO/Cu2O-C tandem cell exhibited 0.78 mA cm−2 of Jop. [ABSTRACT FROM AUTHOR]

Nitinol alloys have recently drawn significant attention and interest in a broad range of applications, due to their excellent shape memory properties, super elasticity and corrosion resistance. However, the low phase transition temperature of the binary Ni-Ti alloy is difficult to meet the high temperature performance requirements, while adding a third alloying element can dramatically improve the phase transition temperature. Additive manufacturing is an effective means for preparing complex shape memory alloy parts, and laser powder bed fusion (LPBF) technology is the most widely used technology. This paper mainly studies the LPBF process optimization process of Ni-Ti-Zr ternary alloy, and reveals the evolution of microscopic defects, microstructure, phase transformation behavior and mechanical properties in LPBF-formed Ni-Ti-based shape memory alloy through the characterization of microstructure and properties. The optimized process window range is 45–80 J/mm3 with the highest relative density of 98.89% under laser power of 250 W, scanning speed of 1000 mm/s, and the preheat temperature of 200 ℃. The average compressive fracture strength is measured to be 1955.77 MPa, and the average elastic recovery strains under pre-compression deformation of 3%, 6%, and 9% are 2.41%, 4.06%, and 6.56%, respectively. Furthermore, the average peak temperature of B19'→B2 is 99.19 ℃, and that of B2→B19' is 28.99 ℃. Compared with the LPBF-made binary Ni-Ti alloys, the phase transformation temperature and thermal hysteresis of Ni-Ti-Zr alloy have been significantly increased by the addition of Zr. It is expected to broaden the application of nickel-titanium alloys under high-temperature conditions, and provide a theoretical reference for LPBF forming of high-performance nickel-titanium-based shape memory alloys. [ABSTRACT FROM AUTHOR]

Mine monitoring system relies on display to in-situ monitor underground environment, but electrochemical corrosion from through-hole film in gate driver on array unit may threaten life safety of underground personnel. This work thus attempts to prepare indium tin oxide/copper/indium tin oxide film on through-hole, and adjust Cu layer thickness to block vapor with proper etching slope angle, so as to improve the electrochemical corrosion resistance. The results show that, surface of film with 841-nm thick Cu layer has few holes, and its particle size is uniform. The film exhibits superior electrical characteristics (Rs=0.024 Ω/sq) and appropriate etching slope angle (67°). The 841-nm film also has larger polarization resistance (3871 Ω) and smaller corrosion current density (1.296 ×10−5 A/cm2). Noticeably, a display screen assembled with 841-nm film exhibits optimal electrochemical corrosion resistance, and can pass field test of double 85 conditions (85 °C with relative humidity of 85 %), presenting a long duration of 1000 h. A correlation mechanism of Cu thickness on the electrochemical corrosion resistance is also proposed to inspire development of high-performance display in safe. • ITO/Cu/ITO is prepared as through-hole film for GOA unit. • Adjusting Cu thickness improves electrochemical corrosion resistance. • Screen with 841-nm film has 1000-h duration in field test under double 85 conditions. • Blocking vapor intrusion and suitable etching slope angle can reduce film corrosion. [ABSTRACT FROM AUTHOR]

Highly transparent Tm 3+ doped terbium gallium garnet single crystal was grown by the Czochralski(Cz) method for magneto-optical applications. The single-crystal X-ray diffraction confirms that the compound crystallize in the cubic systems with the structure a = b = c = 1.2338 nm. The temperature dependence of the magnetic susceptibility indicates that the Tm:TGG crystal exhibits paramagnetic behavior over the experimental temperature-range 10–300 K. Transmittance spectra and the Faraday rotation have been investigated, which demonstrates that the as-grown crystal shows a high visible transparency and yields a lager Faraday rotation comparable to that of TGG crystal. The increasing of the Verdet constant at measured wavelength and high thermal property show the superior characteristics of Tm 3+ doped TGG compared to the pure TGG, indicating that it has significant development for magneto-active materials used in Faraday devices at visible and near-infrared regions (VIS-NIR). [ABSTRACT FROM AUTHOR]

High optical quality Tb 3−x Nd x Ga 5 O 12 (TNGG) single crystal has been grown by Czochralski technique. The absorption spectrum in the wavelength range of 300–1600 nm has been measured at room temperature, as well as the weak absorption at 1064 nm, and the spectral characteristics were analyzed in detailed. Results show a superior transparency in the near-infrared region. Thermal conductivity and laser induced damage threshold (LIDT) measurements were carried out to check its potential usage. Magnetic properties of the as-grown crystal were studied and showed paramagnetism. The magneto-optical properties were studied and the specific Faraday rotation of the as-grown crystal was measured at 1064 nm wavelength. The Verdet constant and magneto-optical figures of merit (V/α) calculated are 41 rad m −1 T −1 and 2.56 × 10 2 rad/T at 1064 nm, which are both larger than that of commercial TGG (2.44 × 10 2 rad/T). The results indicated that the TNGG shows a superior properties than that the commercial TGG and could be a promising candidate magneto-optical material in the wavelength of 900–1450 nm. [ABSTRACT FROM AUTHOR]

In this work, Zn-1.5Cu-1.0Ag-xZr (x = 0, 0.1, 0.5, 1.0) alloys were used as raw materials to research the effects of Zr content and hot rolling on the microstructure and mechanical properties of the alloys. The results revealed that as-cast Zn-1.5Cu-1.0Ag alloy was composed of η-Zn phase and (Ag, Cu) Zn 4 phase. After Zr addition, Zn 22 Zr was precipitated in both as-cast and as-rolled Zn-1.5Cu-1.0Ag-xZr alloys, and a new phase of CuZn 5 was observed in as-rolled Zn-1.5Cu-1.0Ag-xZr alloys, resulting in the second phase strengthening. It was demonstrated that the grain sizes of the as-rolled alloys were much smaller than those of as-cast alloys, while Zr had slight effects on the grain sizes. In addition, Zn-1.5Cu-1.0Ag-0.1Zr alloy has the best as-cast and as-rolled mechanical properties, and the yield strength, ultimate tensile strength and elongation of above two alloys are 84.18 ± 0.71 MPa, 117.79 ± 0.52 MPa, 3.73 ± 0.40% and 218.14 ± 0.04 MPa, 244.83 ± 0.57 MPa, 64.50 ± 4.60%, respectively. Moreover, the strength and elongation of both as-cast and as-rolled Zn-1.5Cu-1.0Ag-xZr alloys increase initially and then decline with the increase of Zr content. • In this work, it can be proved that hot rolling can significantly reduce the grain sizes of as-cast alloys. • Among all the developed alloys, as-rolled Zn-1.5Cu-1.0Ag-0.1Zr alloy has the best comprehensive mechanical properties. • The strength and elongation of Zr modified alloys increase initially and then decline with growing of Zr content. 244.83 MPa [ABSTRACT FROM AUTHOR]

Fe-rich particles that contain silicon were observed in commercially pure magnesium, which contained less than 25 ppm Fe. Based on the simulated phase diagram, silicon, even at low ppm levels, promotes the formation and growth of Fe-rich particles. The studied pure Mg showed a high corrosion rate (>2 mm/year) in 3.5 wt.% NaCl solution, although the Fe content is far below the widely accepted corrosion tolerance limit of Fe (170 ppm by weight). The formation of the Si-containing Fe-rich particles is one of the main reasons for the high corrosion rate observed. Consequently and importantly, the corrosion tolerance limit of iron in magnesium is significantly reduced by the presence of traces of silicon. [ABSTRACT FROM AUTHOR]

• New core/shell Bi 12 O 15 Cl 6 /BiOI hybrid junction was prepared by a facile in-situ generation method. • Bi 12 O 15 Cl 6 /BiOI can effectively remove MO, TC and E.coli under LED light. • h+, •O 2 - and •OH are all active substances in photocatalytic reactions and possible degradation pathway of TC was proposed. • Fermi level reached new equilibrium between p-type BiOI and n-type Bi 12 O 15 Cl 6. • The core-shell structure and n-p junction effectively promote the separation and migration of photogenic carriers. The construction of composite photocatalytic materials with compact heterojunction is of great significance for improving the properties of materials. To achieve this goal, novel core/shell Bi 12 O 15 Cl 6 /BiOI photocatalyst, with n-p junction heterojunction, was prepared by using p-type BiOI nanosheet coating with lamellar n-type Bi 12 O 15 Cl 6. A series of techniques including XRD, TEM, HRTEM and BET confirmed the structure of Bi 12 O 15 Cl 6 /BiOI. As expected, methyl orange (MO), tetracycline (TC) and E. coli can be effectively removed by the novel photocatalyst under LED light illumination. The optimal sample Bi 12 O 15 Cl 6 /BiOI can degrade 90.3% MO in 90 min, degrade 75.5% TC in 180 min, and completely destroy E. coli in 40 min. Photocurrent and electrochemical impedance analysis (EIS) show that the separation efficiency of photo-excited electron-hole pairs in the composite material is significantly improved. Between n-type Bi 12 O 15 Cl 6 and p-type BiOI semiconductor, a Fermi level movement produced a more negative conduction band position and a more positive valence band position, which is conducive to the production of active species and the photocatalytic redox reaction. Moreover, the effects of catalyst dosage and pollutant concentration on the degradation of MO and TC were systematically investigated. The capture experiment proved that the superoxide anion radicals (•O 2 −) and holes (h+) are main active species in photocatalytic reaction. The intermediates were identified by mass spectrometry analysis (MS), and the possible photocatalytic degradation pathway of TC was proposed. [ABSTRACT FROM AUTHOR]

In the present work, with the addition of ZnO nanoparticles (NPs) as Zn source, the Zn-incorporated TiO 2 coatings were successfully produced by the facile one-step micro-arc oxidation (MAO) method. The influence of current density on the microstructural features and biological properties of Zn-incorporated TiO 2 MAO coatings were systematically examined. It is revealed that, at a relatively low current density of 0.1 A/cm2, Zn species either locate on the coating surface as ZnO nano-sheet clusters or entrap within the coating. By contrast, Zn species tend to fuse into the coating at a relatively high current density of 0.5 A/cm2, which exhibits a three-layered structure with significant difference of crystallinity, composition and morphology between different layers. The biological experiments indicate that different current densities result in different osteogenic activities and antibacterial properties of Zn-incorporated TiO 2 coatings. The presence of a Zn-depleted amorphous outer-layer on the MAO coating produced at the current density of 0.5 A/cm2 favours the deposition of apatite-like phases, but retards the release of Zn ions, which thus results in its higher osteogenic activity with lower antibacterial capability compared to that produced at the current density of 0.1 A/cm2. In summary, dual-functional Zn-incorporated TiO 2 coatings could be successfully produced through the facile one-step MAO method, with both antibacterial property and bone formability significantly affected by the current density of MAO process. • Dual-functional Zn-incorporated TiO 2 coatings are successfully produced using one-step micro-arc oxidation method with ZnO nanoparticles as Zn source. • The coating formation process is closely associated with the energy released pre discharge site. • A three-layered Zn-incorporated TiO 2 coating could be fabricated through micro-arc oxidation at the current density of 0.5 A/cm2. • Antibacterial property and bone formability of Zn-incorporated TiO 2 coatings are closely associated with their microstructural features. • Biological properties could be controlled by adjusting the current density of micro-arc oxidation process. [ABSTRACT FROM AUTHOR]

CuI is a wide bandgap p-type transparent conductor with promising optoelectronic properties. However, conventional CuI films prepared through the iodination of Cu films exhibit rough surface, poor stability and excessively high hole concentration, hindering its application. Herein, we introduce CuI−Ga 2 O 3 composite films as a substitution to overcome the shortcomings of pure CuI. During the iodination process, Ga 2 O 3 hindered the mobility of CuI grain boundaries, resulting in small grain size and low surface roughness. After the charge re-equilibrium and low-energy carrier filtering at the interface between Ga 2 O 3 and CuI, the hole concentration in the films decreased by an order of magnitude. Due to the interface effect of Ga 2 O 3 at the grain boundaries of CuI, the hole mobility increased by 5 times, and the conductivity improved by 53%. The ultra-wide band gap of Ga 2 O 3 enhanced the transmittance of CuI films in short wavelength region. Ga 2 O 3 served to passivate the grain boundaries of CuI, preventing the oxidation of CuI and the loss of iodine, consequently improving the stability of the films. This work will deepen the understanding of the failure and hole transport mechanisms of CuI films. • The second phase Ga 2 O 3 inhibits the movement of CuI grain boundaries. • Ga 2 O 3 reduces the surface roughness of CuI films. • CuI−Ga 2 O 3 films have lower hole concentration, higher conductivity and hole mobility. • CuI−Ga 2 O 3 films exhibit better stability in ambient than pure CuI films. [ABSTRACT FROM AUTHOR]

Abstract It is a great challenge to prepare high capacitance negative electrodes for high energy density supercapacitor devices. In this work, nitrogen doped carbon spheres in-situ grown on Ni foam (N doped CS/NF) are prepared as a binder-free negative electrode for supercapacitors. Due to the formation of hierarchical porous structure and N contents after nitrogen-doping, the specific area and electrochemical active sites on the surface of the electrode are effectively increased. Therefore, the specific capacitance of N doped CS/NF electrode is remarkably improved compared to pristine carbon spheres electrode. The synthesized N doped CS/NF negative electrode provides a high areal specific capacitance (C A) of 5.75 F cm−2 at 5 mA cm−2 and mass specific capacitance (C m) of 287.5 F g−1 at 0.25 A g−1. Furthermore, the electrode shows an excellent cycle stability of 115.6% after 10000 cycles at 100 mA cm−2. This study proposes a synergistic approach to enhance the electrochemical performance of supercapacitor's negative electrode. Highlights • In-situ growth method eliminated the resistance of non-conductive binder. • The nitrogen doping strategy produced a novel morphology with porous structure. • Capacitance was significantly increased through nitrogen doped retreatment. [ABSTRACT FROM AUTHOR]

Due to its excellent shape memory effect and super elasticity, NiTi Shape Memory Alloy (NiTi SMA) has broad application prospects in aerospace, ship, biomedicine and other fields. Laser powder bed fusion (L -PFB) has proven to be a feasible way to fabricate NiTi with a complex and precise structure. In this study, a 3D transient multi-physics model based on the computational fluid dynamics (CFD) model is proposed, which incorporates the effects of convective heat transfer and radiation heat transfer on the forming quality of parts and mechanical models such as thermal buoyancy. The temperature field and stress field distribution during the L -PBF forming process of NiTi alloy were studied by using this multi-physics model. Furthermore, the influence of different process parameters on the shape of the molten pool was analyzed, and a nonlinear regression equation was proposed to predict the size of the molten pool. The proposed model is verified by experimental results with a prediction error of 3 %−8 %. Both numerical and experimental results demonstrate that under the process parameters of P = 125 W and V = 500 mm/s, the shape of the molten pool is stable and the NiTi single track is continuous. This work illustrates the reliability of the established simulation method and provides a timesaving approach to optimize the L -PFB process parameters of nickel-titanium alloy. [Display omitted] • Using Ansys-Fluent, the process parameters of NiTi L -PBF process were optimized. • Influence of process parameters on molten pool morphology during NiTi L -PBF process. • A reliable CFD simulation model of NiTi L -PBF process was established. • The equations for estimating the NiTi melt pool width and the optimal process parameters for NiTi are given. • The mechanism of melt pool morphology change during NiTi L -PBF process is revealed. [ABSTRACT FROM AUTHOR]

The effect of heat treatment on the microstructure and properties of Mg-4Al-0.25Si-0.3Ca alloy was systematically studied. The results showed that after solution treatment at 420 ℃ for 10 h and 500 ℃ for 3 h, then aging at 220 ℃ for 7.5 h, the shape of Mg 2 Si and CaMgSi phases changed from continuous to discontinuous, while the Mg 17 Al 12 phased precipitated in the way of continuous precipitation in grains and discontinuous precipitation at grain boundaries during aging. The UTS of the alloy increased from 174.3 ± 4.0 MPa to 194.0 ± 5.0 MPa, and the corrosion current density decreased by 54%, The corrosion resistance was also improved, but the elongation decreased from 10.38 ± 0.37% to 9.1 ± 0.46%. • The Mg2Si phase and CaMgSi phase changed from continuous to discontinuous after 420 ℃ × 10 h, 500 ℃ × 3 h and 220 ℃ × 7.5 h. • After heat treatment, the UTS increased from 174.4 MPa to 194.0 MPa, the Icorr decreased, but the elongation decreased slightly. • The Mg17Al12 phase precipitated in two methods: intragranular continuous and grain boundary discontinuous precipitation. [ABSTRACT FROM AUTHOR]

Band gap engineering has been opening a way to enhance the performance of two-dimensional (2D) material devices. Here we report a synthesis of ternary MS 2(1−x) Se 2x (M = Mo, W) alloys with a band gap tunability of ∼170 meV using a solid state reaction method. X-ray photoelectron spectroscopy and Raman scattering characterizations reveal that the change of Se contents can be utilized to tune the composition of the ternary MS 2(1−x) Se 2x (M = Mo, W) alloys. UV–vis–NIR absorption results conform the realization of tunable band gap in MS 2(1−x) Se 2x (M = Mo, W) alloys tailored by different Se contents. The electrical transport investigation of the ternary alloys exhibits an n-type semiconductor behavior demonstrated by back-gated field effect transistors. [ABSTRACT FROM AUTHOR]

It is still a great challenge to design efficient and stable photocatalysts to effectively remove organic pollution in water. A new type Bi 12 O 15 Cl 6 /SnO 2−x Z-scheme heterojunction was successfully constructed. The best sample 30% Bi 12 O 15 Cl 6 /SnO 2−x can degrade 86.7% TC within 90 min and 99.7% RhB within 75 min under LED light. The morphology, structure, optical and electrochemical properties of the photocatalyst were characterized by using different testing techniques. Efficient photoinduced charge transfer and separation efficiency was confirmed by photocurrent and electrochemical impedance spectra (EIS) in Bi 12 O 15 Cl 6 /SnO 2−x structure. The active substances, intermediate product and photodegradation pathway in degradation process were revealed by capture test and mass spectrometry (MS) measurement. In photocatalytic process, h+, •O 2 − and •OH are the main active species, and h+ is the most important active substance. In addition, the photocatalytic mechanism of charge separation is also proposed, which provides a new opportunity for the construction of photocatalysts and the degradation of organic pollutants in the water environment. • A novel Z-scheme Bi 12 O 15 Cl 6 /SnO 2−x heterojunction containing oxygen vacancy was prepared. • Degradation activity of Bi 12 O 15 Cl 6 /SnO 2−x on TC and RhB was significantly increased in LED light. • h+, •O 2 - and •OH are active species in photocatalytic process, and h+ is the main active substance. • The introduction of SnO 2−x enhances the transition of electrons and the absorption of light. • Z-scheme system promote the charge transfer and redox ability of Bi 12 O 15 Cl 6 /SnO 2−x. [ABSTRACT FROM AUTHOR]

Copper(II) hydroxides, particularly Cu(OH) 2 micro/nanostructures, are metastable under normal conditions. Notably, Cu(OH) 2 micro-/nanostructures undergo structural restructuring and phase transitions during electrochemical reactions. In this study, the effects of electrolyte concentration, current, and duration of the electrochemical reaction on the crystal morphology, structure, and chemical composition of Cu(OH) 2 micro-/nanostructured composite electrodes were investigated by anodic oxidation. The results showed that a Cu(OH) 2 nanorod-like structure was formed on the electrode surface in the KOH electrolyte at a concentration of 3 M, while Cu 2 O crystals were synthesized at electrolyte concentrations of 1 M and 6 M. The growth current of the Cu(OH) 2 nanorod-like structures ranged from 30 mA to 70 mA. At a reaction time of 10–80 min, the micro-/nanostructure of the electrode surface changed from an unstable Cu 2 O to a stable CuO phase through metastable Cu(OH) 2. The synthesized Cu(OH) 2 composite electrode exhibited an area-specific capacitance of 2777 mF cm–2 at a scanning rate of 10 mV s–1. In particular, the relationships between the surface morphology, structure, and chemical composition of the Cu(OH) 2 composite electrode and the electrolyte concentration during cyclic voltammetry were studied. The results showed that in the KOH electrolyte at 1 M concentration, the Cu(OH) 2 micro-/nanostructure transformed into Cu 2 O under electrochemical action, Cu(OH) 2 transformed into both the Cu 2 O and CuO phases at 3 M electrolyte concentration, and Cu(OH) 2 transformed into the CuO phase when the electrolyte concentration was increased to 6 M, indicating that the concentration of the alkaline electrolyte had a significant effect on the reconstruction and phase transformation of the Cu(OH) 2 micro-/nanostructures. These results are expected to address the pressing issues in the application of metastable Cu(OH) 2 micro/nanostructured composite electrodes in high-performance supercapacitors, such as insufficient energy, mass transfer, and structural instability. [Display omitted] • The controlled synthesis of Cu(OH) 2 micro-/nanostructures was realized. • Cu(OH) 2 micro-/nanostructures undergo structural restructuring and phase transitions during electrochemical reactions. • The factors affecting the evolution of Cu(OH) 2 micro-/nanostructures were clarified. [ABSTRACT FROM AUTHOR]

4-Aminothiophenol (4-ATP, a toxic pesticide intermediate) residues in waste water endanger water ecology and human health. Therefore, the development of reliable surface-enhanced Raman scattering (SERS) substrate is a promising strategy for monitoring and preventing 4-ATP pollution. In this work, a core-shell structured Ag@ZnS hybrid, consisting of Ag nano-core and ZnS nano-shell, was fabricated and employed as a SERS substrate to detect 4-ATP. Owing to the specific core-shell structure, epy as-prepared Ag@ZnS substrate is stable against oxidation and spontaneous agglomeration of Ag NPs, enjoying good stability and uniform hot spots. Moreover, the formation of heterostructure between Ag-core and ZnS-shell offered a remarkable chemical enhancement for the Raman signals. The optimized Ag@ZnS substrate showed high sensitivity for rhodamine 6 G (R6G, 10−9 M) and methylene blue (10−8 M) probes, as well as 4-ATP (10−8 M) target analyte. Likewise, the superior reproducibility (RSD<5.50 %, n = 16) and good stability (79.5 % of initial strength after 28 days) for 4-ATP makes this substrate a good candidate for actual determination of trace 4-ATP. This work proposes a strategy to fabricate a reliable SERS substrate with high sensitivity and superior reproducibility, and the designed Ag@ZnS substrate may be applicable to monitor 4-ATP residues in wastewater. • Core-shell Ag@ZnS hybrids were fabricated as a substrate for SERS detection of 4-ATP in water. • The core-shell structure reduces the aggregation of Ag NPs, and enhances its oxidation resistance. • Ag@ZnS exhibits good sensitivity and superior reproducibility and stability for 4-ATP. [ABSTRACT FROM AUTHOR]

Searching for high-efficiency and earth-abundant electrocatalysts towards hydrogen evolution reaction (HER) is one of the most promising pathways to ameliorate environmental contamination. In this work, we report a facile protocol to achieve the synthesis of the coupled molybdenum carbide and molybdenum nitride (Mo 2 C/Mo 2 N), in which ammonium heptamolybdate (AHM) serves as molybdenum source and hexamethylenetetramine (HMT) is chosen as a N-containing carbon source. By virtue of adjusting the ratios of precursors and carbonization temperatures, a variety of products with different structural features and HER performance can be obtained. Compared to single component of carbide or nitride, the Mo 2 C/Mo 2 N hybrid prepared with AHM/HMT ratio of 1:2 at 700 °C shows superior catalytic activity, with an overpotential of 205 mV required to drive 10 mA cm−2 of current density and a Tafel slope of 71.8 mV dec−1. The boosted HER performance is attributed to the synergistic effect between Mo 2 C and Mo 2 N, and the electronic modulation of active sites due to N-doping. • Facile synthesis of coupled Mo 2 C/Mo 2 N hybrid is demonstrated. • The precursors composition and temperatures cause the change of phase structure. • The structure-performance correlation is investigated. • The heteroatom N doping could modulate the electronic structure of active sites. • The optimized catalyst presents favorable HER activity and excellent stability. [ABSTRACT FROM AUTHOR]

Abstract In this work, Ce/Mn dual-doped LaAlO 3 ceramics have been synthesized via a facile microwave sintering method. From the detailed investigations of Fourier transform infrared spectroscopy, it has been found that Ce/Mn co-doping can dramatically improve the far-infrared emission capability of LaAlO 3 ceramics in the range of 8–14 μm. After co-doping of Ce and Mn, Ce4+ ions in polyhedron site (A-site) induce the transformation of Mn4+ to Mn2+ in octahedron site (B-site), which causes the severe lattice distortion of the unit cell and strengthens the vibration intensities of asymmetrical Mn-O-Mn and Mn-O-Al bonds for the promotion of the far-infrared emissivity. Such dual-doped and perovskite-type LaAlO 3 ceramics with excellent far-infrared emission shows great potential as a new generation of far-infrared radiation materials for energy conservation applications. Graphical abstract Image 1 Highlights • Ce/Mn dual-doped LaAlO 3 ceramics are prepared via microwave sintering approach. • Microwave sintering is a high-efficiency method for perovskite-type phase formation. • Ce/Mn co-doping causes the enhancement of lattice strain and asymmetrical vibration. • Ce/Mn dual-doped ceramics possess appealingly high far-infrared emissivity. [ABSTRACT FROM AUTHOR]

High-performance Ti-based nanocomposites reinforced with TiB nanowires with a network-woven structure were fabricated, and the growth of the TiB nanowires was investigated through comparative sintering and annealing experiments. TiB nanowires nucleated from the surfaces of the Ti powder particles and then grew into the particles. They remained stable in the Ti matrix when isothermally annealed at 1000 °C for 24 h, but coarsened noticeably during rapid heating to 1200 °C. The coarsening of the TiB nanowires was found to occur through stacking of thinner TiB nanowires, which can be regarded as a detachment-attachment controlled Ostwald ripening process and is affected by the surface free energy of the faceted TiB. Tensile property tests revealed that TiB nanowires are distinctly advantageous over TiB microwhiskers in strengthening the Ti matrix. The as-sintered Ti-based nanocomposites achieved both high tensile strengths (>800 MPa) and excellent tensile ductility (>20%). [ABSTRACT FROM AUTHOR]

Transmission electron microscopy and energy dispersive X-ray spectroscopy have been used for crystallographic and compositional characterization of nano-precipitates distributed within the α-Zr matrix of the ZIRLO alloy. Intermetallic nano-particles with the C14 Laves-phase structure were found to be the dominant precipitate phase typically larger than 60 nm in sizes, which is assigned to the Zr(Fe,Nb) 2 formula with Fe and Nb being mixed on the second sublattice sites in the bracket. Stacking faults were also observed in the ternary Laves phase, together with dislocations presenting on prism planes of the matrix solid solution. Besides, some fine spherical β-Nb particles about 30 nm in size were also found to precipitate within the α-Zr grains, with the α/β interface being crystallographically coherent. [ABSTRACT FROM AUTHOR]

The effects of post-deposition oxygen annealing temperature on the physical, chemical, and optical properties of gallium oxide (Ga 2 O 3) films were systematically studied in this work. First, Ga 2 O 3 films were deposited on Si (100) substrates by atomic layer deposition (ALD) and then annealed at 500–900 ℃, respectively. Several standard surface analysis methods were used to characterize the Ga 2 O 3 films before and after annealing. X-ray diffraction (XRD) patterns illustrated that the as-deposited amorphous film transitioned to β-phase after annealing at temperatures greater than 600 ℃. Atomic force microscopy (AFM) images showed that the grain size and roughness of the films significantly increased when annealed above 700 ℃. Transmission electron microscopy (TEM) tests presented that the interface microstructure was slightly affected by the annealing process. The effects of the annealing process on optical properties were performed using photoluminescence spectroscopy (PL) and spectroscopic ellipsometry (SE). Moreover, X-ray spectroscopy (XPS) was utilized to extract the oxygen vacancy (V O) concentration, bandgap, and the energy band alignment of Ga 2 O 3. With increasing annealing temperature, it was found that the atomic ratio of O/Ga increased while V O decreased monotonically from 47.4 % to 27.0 %. Density functional theory (DFT) simulation further accounted for energy band shifts resulting from the variation of V O. This study provides a means to achieve high-quality β-Ga 2 O 3 films, highly significant for applications of β-Ga 2 O 3 -based ultraviolet photodetectors and other relevant devices. • The temperature-dependent annealing effect on chemical state, microstructure, and optical properties of Ga 2 O 3 film is systematically studied. • The relationship of the band structure with annealing temperature and oxygen vacancy defects is established. • The energy bandgap of Ga 2 O 3 can be tuned from 4.75 eV to 4.94 eV by controlling the annealing temperature. • The DFT theoretical calculation combined with XPS results gives insight into the effect of oxygen vacancy defects on the properties of the Ga 2 O 3. [ABSTRACT FROM AUTHOR]

Y 0.5 Ca 0.5−x In x BaCo 3.2 Ga 0.8 O 7+δ (x = 0.0 or 0.1, and denoted as YCBCG, YCIBCG, respectively) oxides are synthesized and investigated as cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs). The In content (x) significantly affects the properties of Y 0.5 Ca 0.5−x In x BaCo 3.2 Ga 0.8 O 7+δ . The YCIBCG oxide exhibit superior phase stability compared to YCBCG at high temperatures (700–950 °C). The substitution of In for Ca improves the long-term phase stability at higher temperatures, but slightly degrades the electrochemical performance. Thermal expansion coefficient (TEC) values of the YCBCG and YCIBCG oxides are 9.8 × 10 −6 K −1 and 9.7 × 10 −6 K −1 in the range of 30–850 °C, respectively, which provides good mechanical compatibility with the electrolyte (10.9 × 10 −6 K −1 for LSGM). The interfacial polarization resistances for YCBCG and YCIBCG cathode are as low as 0.140 Ω cm 2 and 0.146 Ω cm 2 at 700 °C, respectively. The maximum power densities of the NiO–SDC/SDC/LSGM/YCBCG and NiO–SDC/SDC/LSGM/YCIBCG cells are 434 and 415 mW cm −2 at 800 °C, respectively with a 300 μm thick electrolyte. The results of this study demonstrate that YCBCG and YCIBCG are very promising cathode materials for intermediate temperature SOFCs. [ABSTRACT FROM AUTHOR]

Cerium doped TiO 2 nanopowders were prepared by hydrothermal method with cerium nitrate. The samples were characterized by high-resolution transmission electron microscope (HRTEM), X-ray diffraction (XRD), X-ray photoemission spectroscopy (XPS), ultraviolet–visible light diffuse reflectance spectra. Results show that the crystal of cerium dioxide can be observed in the grains of TiO 2 . The morphology of TiO 2 prepared by hydrothermal methods changed from nanosheets to nanopowders by cerium doping. Meanwhile cerium doping can significantly reinforce the absorption of visible light, and adjust the absorption cut-off wavelength, from 373 nm to 499 nm for the undoped and the 25% doped 499 nm samples respectively. With the increase in doping ratio of cerium, the band gaps also decreased from 3.32 to 2.48 eV. Based on our observations, it can be concluded that cerium oxide can improve the absorptivity of TiO 2 and may have potential applications in the areas of solar cells and photocatalysis. [ABSTRACT FROM AUTHOR]

An important aspect of materials phenomena during the service of structural Zr alloys for nuclear cladding components is associated with hydrogen picking, which leads to the formation of δ-hydrides ZrH x (x = 1.55 or 1.66), the structural evolution of which is essential to the mechanical stability of the cladding components. In this work, we report the formation of δ-hydrides due to accidental hydrogen pickup, using high-resolution transmission electron microscopy (HRTEM). The results showed that the habit plane for relatively large δ-hydrides was (0001) α , with the plate morphology. The morphology for regions with populous nano-sized hydrides is irregularly blocky, albeit being of the same orientation relationship between hydrides and matrix. Such remarkable morphological change is associated with multi-nucleation and twinning in the hydrides crystals in the nano-scale. [ABSTRACT FROM AUTHOR]

ZnO thin films were prepared in the electrolyte with different methanol ratio by cathodic electrodeposition method. Microstructure, surface morphology, optical properties and wettability of the thin films were investigated by X-ray diffractometer, field-emission scanning electron microscope, ultraviolet–visible spectroscope, fluorescence spectrometer and water contact angle apparatus. Increase of methanol ratio in the solvents may restrain the (0 0 2) plane preferential orientation in some extent. Change of current density curves with the ratio of methanol in the solution play a vital role on electrochemical reaction kinetics, microstructure and/or surface morphology of ZnO thin films. With the methanol ratio increase from 0 to 0.8, the surface morphology changes from nanorods to net-like nanostructure. The adsorbed NO 3 − ions on the polar planes hinder the crystal growth along the c -axis and redirect the growth direction along the nonpolar planes. The maximum and minimum band gaps have been obtained in the ZnO thin films with the methanol ratio of 0.4 and 0.6, respectively. Change of contact angle before UV irradiation may be related to surface morphology and oxygen vacancies. The maximum light-induced water contact angle change has been observed in the sample with the methanol ratio of 0.8. The results may be attributed to the higher surface roughness and net-like morphology. [ABSTRACT FROM AUTHOR]

• The EM wave absorption performance are manipulated by the morphology, composition and loading of Ni/NiO microspheres. • The porous Ni/NiO550 microspheres possess multiple electromagnetic wave absorption channels. • Ni/NiO550-45 achieves excellent electromagnetic wave absorption performance. [Display omitted] The research and development of electromagnetic wave absorbing materials with light weight, thin thickness, powerful absorption, and wide frequency bandwidth is a long-term pursuing. Here, Ni/NiO microspheres were synthesized through hydrothermal reaction followed by thermal reduction process. The experimental results indicated that the electromagnetic parameters and electromagnetic wave absorption performance were seriously affected by the morphology, composition and loading of Ni/NiO microspheres. When the reduction temperature rose to 550 °C, Ni/NiO550 showed a special porous-microsphere structure which assembled by irregular Ni/NiO core-shell nanorods. The micro-size combination of porous and core-shell structures, the affluent surface area, sufficient NiO-Ni interface, high-concentration active sites were conducive to the impedance matching and diverse loss mechanism including conductive loss, interfacial polarization, dipole polarization, natural/exchange resonance and multiple scattering. Finally, 45 wt% porous Ni/NiO/paraffin composite exhibited high reflection loss (− 52.15 dB) and broad effective frequency bandwidth (3.22 GHz) at a thickness of 2.17 mm. [ABSTRACT FROM AUTHOR]

• TiO 2 nanorod arrays were decorated with AgVO 3 quantum dots (QDs) on and a layer of V 2 O 5 film, forming a heterojunction material for removal pollutants and photoelectrochemical (PCE) water splitting. • The favorable sunlight-driven PCE activity can be attributed to the n-type semiconductor TiO 2 coupling to the p-type semiconductor V 2 O 5 , small band gap AgVO 3 , and to the formation of Z-scheme (double type-II band gap) heterojunction materials through Fermi level alignment. • The Mott-Schottky plots clearly reveal that the donor density of AgVO 3 /V 2 O 5 -TiO 2 photoanodes increases (∆ N D =6 × 1016 cm−3) significantly under photo-electrochemical (2.15 × 1018 cm−3) than under electro-chemical (2.09 × 1018 cm−3). • We provide new insight into the performance of this heterojunction used for water splitting, in addition to demonstrating a low-temperature hydrothermal method, and that this insight would be of interest to the many researchers working in the field. • While the individual components are well known for these applications in other heterojunction materials, given that this combination of components appears to be new, and with a significant performance improvement over the state-of-the-art. In this study, we fabricated TiO 2 nanorod arrays (TiO 2), which were decorated with AgVO 3 quantum dots (QDs) on and a layer of V 2 O 5 film, forming a heterojunction material for removal pollutants and photoelectrochemical (PEC) water splitting. The AgVO 3 /V 2 O 5 -TiO 2 nanorod arrays (AgVO 3 /V 2 O 5 -TiO 2) synthesized by the secondary hydrothermal method were grown on conductive glass to form one-dimensional (1D) nanorod and p-n junction structures. Through experimental characterisation and testing, optical, morphological photocatalysis and PEC characteristics of the materials were measured and studied. The TiO 2 modified with AgVO 3 and V 2 O 5 can significantly improve the visible light optical absorption, the reduce the electron-hole pair binding rate and shorten the band gap (3.07–1.41 eV) of TiO 2. The resulting photocurrent density (116 uA/cm2) and photodegradation efficiency (rate constant, k = 0.025 min−1) of AgVO 3 /V 2 O 5 -TiO 2 are approximately 20 (6 uA/cm2) and 5 times (0.005 min−1) higher than those of bare TiO 2 , respectively. The AgVO 3 /V 2 O 5 -TiO 2 achieved a current density of 10 mA at an overpotential of 246.2 mV and exhibited excellent oxygen evolution reaction (OER) performance. The systematic PEC experiments concluded that the optimized of the TiO 2 interface by AgVO 3 and V 2 O 5 could promote the separation and transport of charge carriers. [ABSTRACT FROM AUTHOR]

• The well-bonded NiTi wall was fabricated by introducing CMT based WAAM method. • The NiTi wall exhibits mainly columnar grains with different morphologies and equiaxed grains near the top surface. • The B2 is the main constituent phase and Ti 2 Ni/Ti 4 Ni 2 O precipitates appear after deposition. • Each layer shows a one-step B2→B19′ transformation and the Ms temperature is lower than that of the as-received wire. • The mechanical properties show position dependence and reliable plasticity. Wire arc additive manufacturing (WAAM) has been proved to be a promising method to fabricate large expensive NiTi shape memory alloys with complex geometry. In this study, five layers of NiTi alloy with dimensions of 80 × 12 × 15 mm were deposited by the cold metal transfer (CMT) welding based WAAM process. The macroscopic morphology, microstructure evolution, phase transformation and mechanical properties of each layer were investigated and compared with each other. Each layer of the as-deposited NiTi wall shows a one-step B2→B19′ transformation during cooling and the martensitic transformation temperature (M s) is lower than that of the as-received wire. For the first three layers, the columnar grains growing along the building direction have a larger length-to-diameter ratio and B2 is the main constituent phase. Coarse dendritic Ti 2 Ni/Ti 4 Ni 2 O precipitates are precipitated at the interior of the grains besides grain boundaries. However, grains in the subsequent layers become finer and the region near the top surface are characterized by equiaxed grains, and elliptical Ti 2 Ni/Ti 4 Ni 2 O precipitates mainly concentrate at grain boundaries. The heat-affected zone exhibits the lowest hardness of 233.34HV, followed by a gradually increase among the as-deposited layers and the highest hardness of 331.27HV was obtained at the 5th layer. The highest ultimate tensile strength of 652.46Mpa, together with the elongation of 13.66% and recoverable strain of 2.39% was obtained in the sample which is located at 11.5 mm height away from the substrate. This research provides an innovative method and insights for additive manufacturing NiTi shape memory alloys by introducing CMT based WAAM method. [ABSTRACT FROM AUTHOR]

The Cu/Invar bi-metal matrix composites have a great potential to be used as novel electronic packaging materials. In order to clarify effects of the Invar particle size on microstructures and properties of the composites, two Invar powders of average sizes of 26 µm and 105 µm were employed to fabricated the 50 wt% Cu/Invar composites, respectively, by spark plasma sintering (SPS) at 700–800 °C under vacuum condition with a heating rate of 100 °C/min, a pressure of 50 MPa and a holding time of 1 min. The results indicate that the Cu/ fine Invar (f-Invar) composites have finer Cu grain sizes in which the f-Invar particles are semi-continuously distributed. The composites have typical characteristics of low-angle Cu grain boundaries, high-density Σ3 growth twins and Cu/Invar coherent/semi-coherent interface. On the contrary, the coarse Invar (c-Invar) particles are discontinuously distributed in the Cu/c-Invar composites, resulting in the formation of coarser Cu grain sizes, high-angle Cu grain boundaries and non-coherent Cu/Invar interface. Moreover, compared with the f-Invar particles, the c-Invar ones can not only effectively decrease the Cu/Invar interfacial area, but also prohibit the Cu/Invar interface diffusion, therefore considerably improve thermal conductivity (TC) of the Cu/Invar composites at the cost of a little reduction of tensile strength (R m). It is also clarified that properties of the Cu/Invar composites are sensitive to the sintering temperature. The 700 °C sintered 50 wt% Cu/c-Invar composite has the highest TC of 130.1 W/(m·K). It is very close to the theoretical value predicted by the Maxwell model and much superior to the TCs previously reported in the Cu/Invar composites of the similar Invar fraction. [Display omitted] • SPS technique used to fabricate the Cu/Invar composites at low temperature. • Interfacial characteristics of the composites varied with Invar particle size. • Relationships between microstructures and properties of the composites. • The highest TC among those of the composites of the similar Invar fraction. [ABSTRACT FROM AUTHOR]

The microstructure evolution of a hot extrusion (HEXed) powder metallurgy (PM) nickel-based superalloy was investigated by hot compression tests under different deformation conditions. Optical microscope (OM), electron backscatter diffraction (EBSD) technique and transmission electron microscope (TEM) were applied to investigate the effect of Zener-Hollomon (Z) parameter on the microstructure evolution and nucleation mechanisms of dynamic recrystallization (DRX). The results show the stress-strain curves of the experimental superalloy exhibit obvious characteristics of DRX. Microstructure observations reveal that with the decrease of the Z parameter, both the degree of DRX and the size of DRX grains for the experimental superalloy gradually increase. The nucleation mechanism of DRX of the experimental superalloy is related to the Z parameter. Under the condition of lower Z value, discontinuous dynamic recrystallization (DDRX) characterized by bulging of grain boundaries is the main mechanism of DRX, while continuous dynamic recrystallization (CDRX) is considered to be an auxiliary mechanism for DRX nucleation in hot deformation. The existence of twins and γ' phase also has a major effect on the DRX nucleation mechanism of the experimental superalloy. Under the condition of higher Z value, CDRX and DDRX occur simultaneously, while CDRX characterized by progressive subgrain rotation can also be regarded as an important nucleation mechanism of DRX. [Display omitted] • Four nucleation mechanisms of DRX in the PM superalloy are clarified. • DDRX is the principal nucleation mechanism of DRX for all Z parameters. • Twins and γ′ phases play significant roles in the nucleation of DRX at lower Z value. • CDRX is also an important nucleation mechanism of DRX at higher Z value. [ABSTRACT FROM AUTHOR]

The poor machinability of the high-fraction SiCp/Al matrix composites is one of the key factors that hinders its application in electronic packaging. In this study, (0−15) wt% GNFs/SiCp/6061Al matrix hybrid composites are prepared by vacuum hot pressing at 590 °C and 50 MPa with the graphene nanoflakes (GNFs) partially replacing SiCp, the microstructure and ground surface properties of the composite and their effects on the mechanical and thermal properties of the composite are studied, and the machining performance is comprehensively evaluated. The results show that the interface of the composite is well-bonded and no Al 4 C 3 products exist. With increasing GNFs content, the GNFs in the composites tend to agglomerate, the density decreases, and the damage to the ground surface and microstructure increases. Compared to the 54.2 wt% SiCp/6061Al matrix composites, the 5 wt% GNFs/48.4 wt% SiCp/6061Al matrix composites have lower strength but better thermal properties, and show lesser damage of the microstructure and lesser attenuation of the mechanical and thermal properties after grinding. However, with the further increase in the GNFs content, the SiCp crack and drop off and GNFs pull out and peel severely, leading to the greater degradation of the properties of the surface of the GNFs/SiCp/6061Al matrix composites. [Display omitted] • No Al 4 C 3 in the GNFs/SiCp/6061Al matrix composites. • Clarification of the sintering and grinding mechanisms of the composites. • The best microstructures and properties of the composites of 5 wt% GNFs after grinding. [ABSTRACT FROM AUTHOR]

• This work possesses a high ZT ave of 1.23 by nano-TiC ceramic incorporation. • The electron and phonon transport properties are synergistically manipulated. • The samples exhibit excellent improvement in Knoop harness. Bismuth antimony telluride (BiSbTe) composites are the most studied thermoelectric materials around room temperature. However, the extension of commercial applications is mostly restricted by its inferior conversion efficiency and mechanical stability. In this work, we report that the introduction of nano-sized ceramic titanium carbide (nano-TiC) can achieve a high dimensionless figure of merit (ZT) value up to 1.3 at 400 K and an increment in hardness over 37.93% at room temperature in Bi 0.3 Sb 1.7 Te 3 (BST) composites. On one hand, nano-TiC creates BST/TiC interfaces so that total thermal conductivity is reduced. Meanwhile, the Seebeck coefficient increases due to the scattering of carriers through the TiC-driven energy filtering effect. On the other hand, the hardness increases substantially with the addition of TiC resulted from the pinning effect induced hardening by grain boundaries and secondary phases. The results indicate that nano-TiC dispersion into BST matrix is effective for the enhancement in both thermoelectric performance and mechanical properties, which is favorable to practical applications. Moreover, the method of introducing nano-sized ceramic materials can also be extended to other thermoelectric systems. [ABSTRACT FROM AUTHOR]

Novel carbon quantum dots/1D MoO 3-x hybrid junction (noted as CQDs/MoO 3-x) was obtained by a facile hydrothermal route. The CQDs/MoO 3-x photocatalyst was estimated as an effective photocatalyst for inactivating E. coli and S. aureus under LED light. Compared with pure MoO 3 and MoO 3-x , CQDs/MoO 3-x photocatalyst displayed better performance in inactivating E. coli and S. aureus. The results of UV–visible diffuse reflectance spectrum (UV–vis DRS), transmission electron microscopy (TEM) and electrochemical impedance spectrum (EIS) indicated the enhanced photoactivity is ascribed to: (1) MoO 3-x has good absorption property of visible light; (2) the 1D structure of MoO 3-x prolongs the lifetime of photo-excited charge carriers; (3) CQDs modifying 1D MoO 3-x is not only favorable for absorption of visible light, but also for the fast transport and surface separation of the charge carriers. The capture experiment showed that holes (h+) are main active species in the photocatalytic process. This work presents an efficient photocatalyst for water antibacterial treatment. • Novel carbon quantum dots/1D MoO 3-x photocatalyst was successfully prepared. • The hybrid catalyst can inactivate E.coli and S. aureus under LED light. • Holes are main active species in the photocatalytic processing. • CQDs and 1D MoO 3-x are both favorable for the improved photocatalytic activity. [ABSTRACT FROM AUTHOR]

Ca 3 Co 4 O 9+δ ceramic is a potential p-type thermoelectric material for high temperature applications, however, its thermoelectric performance is limited by the strongly interrelated thermoelectric parameters. In this work, we develop an effective method to simultaneously tune the electrical and thermal transport properties of Ca 3 Co 4 O 9+δ. We firstly synthesize Ca 3 Co 4 O 9+δ powders and subsequently obtain surface modified Cu/Ca 3 Co 4 O 9+δ through a well-controlled electroless plating technique followed by a fast Spark Plasma Sintering process. The detailed characterizations of microstructures and chemical compositions of Cu/Ca 3 Co 4 O 9+δ samples suggest that the plated Cu has been doped into the Ca 3 Co 4 O 9+δ after sintering. The doped Cu substitutes Ca ions, creates local oxygen deficiency and increases the ratios of Co3+ and Co4+, which reduces the carrier concentration and induces Ca-missed regions, thus, reducing the electrical and thermal conductivity. This study indicates that introducing metallic Cu phase by chemical electroless technique is a promising method to tune the thermoelectric properties of Ca 3 Co 4 O 9+δ -based ceramics by altering the chemical composition and microstructures. Image 1 • The surface modified Cu/Ca 3 Co 4 O 9+δ composites are prepared with controlled Cu contents. • The plated Cu can be doped into Ca 3 Co 4 O 9+δ after sintering, changing the chemical composition and microstructure. • The Cu plating can simultaneously modify the electrical and thermal transport properties of Ca 3 Co 4 O 9+δ ceramics. [ABSTRACT FROM AUTHOR]