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The Tb3+ doped P 2 O 5 -B 2 O 3 -ZnO-SrO (PBZS system) glasses were prepared by the melt-quenching method. The structural, physical, thermal, and optical properties of the Tb3+ doped PBZS glasses are thoroughly investigated. The thermal behaviour shows that the PBZS system exhibits a higher thermal stability. FTIR and Raman spectra reveal that the lower OH- content and phonon energy favors the fluorescent properties. XPS analysis reveals that the Tb ions predominantly exist in the trivalent state. The Judd-Ofelt theory indicates a higher covalency between the Tb3+ and O2- ions. Based on the excitation spectra, the phonon sideband characteristics of Tb3+ are observed, which has rarely been reported in previous studies. Under 378 nm excitation, all the glasses display cold and intense green emissions. The spectral results indicate that the optimum doping content of Tb 2 O 3 is 1.5 mol%, at which point the quantum yield is 29.67 %, and even reaches or exceeds those of the Tb3+ doped glass-ceramics (28.62 %). The energy transfer between the Tb3+ ions is mainly dominated by the dipole-dipole interactions. The lifetimes obtained are all at the millisecond level. Time-resolved emission spectra confirm the photoluminescent stability of the Tb3+ ions. The PBZS glass doped with 1.5 mol% Tb 2 O 3 presents the higher branching ratio (71.69 % >> 50 %), emission cross-section (2.20 × 10−21 cm2), gain bandwidth (2.09 × 10−27 cm3), and optical gain (3.54 × 10−24 cm2·s). A nearly negligible chromaticity shift (0.94–2.33 × 10−2) in 293–473 K that the Tb3+ doped PBZS glasses feature excellent thermochromic properties and thermal stability. The PBZS glass doped with 1.5 mol% Tb 2 O 3 is a potentially preferable fluorescent material for exploiting green lasers and trichromatic white light-emitting diodes (WLEDs). [Display omitted] • Tb3+ doped P 2 O 5 -B 2 O 3 -ZnO-SrO glasses have been fabricated. • Glass doped with 1.5 mol% Tb 2 O 3 has optimal emission and fluorescent stability. • High quantum yield of 29.67 % even matches or exceeds glass ceramic system. • 1.5 mol% Tb 2 O 3 doped PBZS glass has potential for green lasers and WLEDs. [ABSTRACT FROM AUTHOR]

We report on the superconducting transport properties of B-doped FeSe 0.5 Te 0.5 single crystals grown by the self-flux method. The structure and superconductivity of these samples were carefully analyzed using X-ray diffraction, scanning electron microscopy, and electrical transport measurements. The crystal structure owns the same tetragonal symmetry as PbO. The B-doped samples show a more significant electronic anisotropy in the superconducting state. Microstructural analysis shows that B-doping of FeSe 0.5 Te 0.5 increases the Fe content in the single crystal samples. B-doping decreases T c slightly, resulting in lower irreversibility lines. This work revealed the physical effects of B-doping in FeSe 0.5 Te 0.5 superconductors and inspired a way to regulate the superconductivity through elemental manipulation. • We have successfully grown B-doped Fe(Se, Te) crystal samples and reported superconductivity. • The B-doped Fe(Se, Te) crystal samples that the B and Te element reacts preferentially. • With B doping of the Fe(Se, Te) samples, B irr (0) decreases both due to a decrease in T c and increased anisotropy. • Mechanistic analysis of the suppression of superconductivity in the B-doped Fe(Se, Te) crystal samples. [ABSTRACT FROM AUTHOR]

MnO attracts increasing attention as a lithium-ion battery anode material due to large theoretical capacity and relatively low cost, but its highly instable structure and low conductivity severely plague cycling stability. In addition to improved performance, easy preparation is also important for the development of MnO anode, and hence both of these aspects need attention. Toward this end, herein, a high-performance MnO-based anode material, composed of carbon coated porous nanoclusters assembled from smaller secondary Fe-doped MnO nanoparticles (denoted as Fe-MnO@C), has been prepared through a facile route. The findings demonstrate that the combination of Fe doping and carbon coating enables Fe-MnO@C to have higher structural stability and faster electrochemical kinetics than MnO and MnO@C counterparts. As a result, Fe-MnO@C anode shows outstanding lithium storage performances, maintaining 1038.4 and 512.3 mAh g−1 at 200 and 1000 mA g−1 after 320 and 400 cycles, respectively. Finally, this work not only offers a feasible method for improving MnO anode performance, but also gives a constructive reference for designing facile methods to prepare other advanced metal oxide-based anode materials. [Display omitted] • Dual modification strategies of Fe doping and carbon coating of MnO were achieved simultaneously. • This way offered MnO improved structural stability and electrochemical kinetics. • The as-prepared Fe-MnO@C anode exhibited long life and high capacity. • The findings gave a constructive reference for improving other metal oxide anodes. [ABSTRACT FROM AUTHOR]

Two-dimensional Ti 3 C 2 MXene with high bulk density can act as prospective electrode material to construct high volumetric energy density supercapacitors. Herein, a series of nitrogen-doped Ti 3 C 2 (N-Ti 3 C 2) films are successfully synthesized by adjusting the quantity of urea using a facile solvothermal method. The incorporation of nitrogen atoms can enlarge interlayer spacing and diminish -F terminal groups of Ti 3 C 2 to promote the diffusion and intercalation of electrolyte ions, and bring about defect sites to provide more electrochemical reactive sites, thus improving the specific capacitance of N-Ti 3 C 2. As a result, the 2.0 N-Ti 3 C 2 film shows the highest volumetric capacitance of 2898.5 F cm−3 at scan rate of 2 mV s−1 in 3 M H 2 SO 4 solution, which is mainly attributed to its high pyridinic N content and low -F terminal groups. Density functional theory (DFT) calculations indicate that the doped N atoms have a higher adsorption energy for protons to enhance the pseudocapacitance of 2.0 N-Ti 3 C 2 electrode, and the increased density of states demonstrate the improvement of its electric conductivity after N doping, which promotes the rate performance of 2.0 N-Ti 3 C 2 electrode. The assembled symmetric supercapacitor based on 2.0 N-Ti 3 C 2 film delivers a high volumetric energy density of 40.8 Wh L−1 and good cycling stability. Our work provides an effective and alternative strategy to improve capacitance of other MXenes for high-performance supercapacitors. [Display omitted] • Flexible nitrogen-doped Ti 3 C 2 films are synthesized by a solvothermal method. • Nitrogen atoms can enlarge interlayer spacing and generate defect sites in Ti 3 C 2. • High pyridinic N can act as electron-donors to absorb more electrolyte ions of H+. • Low -F terminal groups are beneficial to enhance pseudocapacitance of N-Ti 3 C 2. • Optimal 2.0 N-Ti 3 C 2 shows a volumetric capacitance of 2898.5 F cm−3 at 2 mV s−1. [ABSTRACT FROM AUTHOR]

Ni2+ doped and Ni2+/Er3+ co-doped Gd 2 MgTiO 6 (GMT) phosphors have been synthesized by conventional high-temperature solid-state reaction method. First-principles calculation and X-ray diffraction analysis proves that Ni2+ ions occupy the Mg2+ sites in the Gd 2 MgTiO 6 matrix at low Ni2+ doping concentration and begin to occupy Ti4+ sites at high Ni2+ doping concentration. The near infrared emissions of Ni2+ ions occupying Mg2+ and Ti4+ sites peak at 1344 nm and 1412 nm, respectively, forming a broad near infrared emission band from 1100 nm to 1700 nm. It is found that Ni2+/Er3+ co-doped Gd 2 MgTiO 6 phosphor is capable to up-convert near infrared photons in the wavelength range of 870–1700 nm to visible 532 nm, 555 nm and 666 nm emission, caused by the energy transfer sensitization process from Ni2+ to Er3+. The Ni2+ and Er3+ concentration dependent up-conversion properties have been investigated and it is found that the Gd 2 MgTiO 6 : 2%Ni2+/5%Er3+ phosphor shows the strongest up-conversion emission, in which the energy transfer efficiencies from the Ni2+ ions occupying Mg2+ and Ti4+ sites to the Er3+ ions are 81.5% and 79.3%, respectively. The Gd 2 MgTiO 6 : 2%Ni2+/5%Er3+ phosphor shows yellow emission under the irradiation of 1342 nm and 1550 nm lasers, and green and orange-red emissions under the irradiation of 980 nm and 1064 nm laser, respectively. The broad band excitability and multi-color up-conversion performance of the Ni2+/Er3+ co-doped Gd 2 MgTiO 6 phosphor suggest that it has wide application prospect in anti-counterfeiting, solar cell efficiency enhancement, infrared detection and so on. • Broadband near infrared emission of Ni2+ is firstly witnessed in Gd 2 MgTiO 6. • Gd 2 MgTiO 6 : Ni2+/Er3+ can up-convert 900–1700 nm light into visible emission. • Ni2+→Er3+ energy transfer and Er3+ excited absorption performs the up-conversion. • The phosphor shows different up-conversion color excited at different wavelength. [ABSTRACT FROM AUTHOR]

Rutile TiO 2 is a competitive white pigment due to its high refractive index and inertness. Uncolored Mg2+ is a promising dopant for the production of TiO 2 pigment because it promotes the anatase-to-rutile phase transition of TiO 2 at lower temperatures (vs. Al3+). However, research on the impact of Mg2+ concentration on TiO 2 phase transition is scarce, and the defect structures are still unknown. In this study, the effect of Mg2+ doping concentration on TiO 2 phase transition was investigated, and the defect structures of Mg2+ doped TiO 2 were proposed. Over 96% conversion of anatase to rutile was achieved with 1.48% Mg doping at 875 °C (vs. Al3+, 1050 °C) for 1 h. By using the Rietveld method, two defect structures—interstitial Mg2+ (Mg int) and substitute Mg2+ (Mg sub)—were quantified. A correlation between the defect structures and the effect on phase transition was established. At low Mg doping level (<1%), the Mg int dominates and weakly promotes the phase transition; At high Mg doping level (>1%), the Mg sub dominates and strongly promotes the phase transition. Additionally, a possible mechanism for the formation of defect structures and how that affects phase transition was proposed. The present results may provide insights into TiO 2 pigment production and modulation of TiO 2 defects for phase transition control and other applications. • 96% conversion of anatase to rutile was achieved at 875 °C (1050 °C in industry). • The two defect structures of Mg2+ doped TiO 2 —interstitial Mg2+ and substitute Mg2+—were quantified by Rietveld method. • The correlation between defect structures and phase transition is established. • The possible mechanism for the formation of defect structures and how that affects phase transition was proposed. [ABSTRACT FROM AUTHOR]

Abstract Ideal electrodes should hold well-defined pore size distribution, high electrical conductivity and superior compatibility. Herein, we present a scalable strategy for the design and generation of macroporous frameworks based on N-doped hollow carbon spheres intercalated graphene film (GNC). In the unique structure, hollow carbon spheres separate the graphene nanosheets and provide convenience for ion entering the film and maximize the ion-accessible surface area. In situ deposition high performance MnO 2 on the surface of GNC film can help to enhance the specific capacity of the compounds. The obtained GNC/MnO 2 binder-free supercapacitor electrode exhibits ultrahigh volumetric capacitance 532.7 F cm−3 at 2 mV s−1. An asymmetric supercapacitor based on GNC/MnO 2 //GNC shows an ultrahigh volumetric energy density of 45.9 Wh L−1 at 1024 W L−1, which is much higher than the reported carbon based materials in aqueous electrolytes. The device also shows an excellent cycling stability with 93.1% initial capacitance after 5000 charge/discharge cycles. The device can light two LEDs, which indicates the potential of the composite for practical application. Graphical abstract Image 1 Highlights • N-doped hollow carbon spheres intercalated graphene film is rationally fabricated. • Macroporous frameworks can provide convenience for ion entering the film. • The GNC/MnO 2 //GNC supercapacitor shows an ultrahigh volumetric energy density of 45.9 Wh L−1. • The assembled asymmetric supercapacitor can successfully glow two parallel LEDs. [ABSTRACT FROM AUTHOR]

In this work, it is successfully achieved to synthesize the three-dimensional flowerlike Ni (1-x) Mn x Fe 2 O 4 (x = 0, 0.02, 0.04, 0.06, 0.08, 0.1) by an environmental hydrothermal method. The morphology and structure of as-prepared Ni (1-x) Mn x Fe 2 O 4 are characterized via X-ray diffraction, scanning electronic microscopy and nitrogen adsorption-desorption isotherms, besides, the magnetic properties of the samples is revealed by vibrating sample magnetometer. The results show that the Ni (1-x) Mn x Fe 2 O 4 are cubic spinel phase with three-dimensional flowerlike microspheres structure assembled by nanosheets, which is exhibited the good performance to remove Congo red (CR). Besides, the samples with good magnetic properties facilitates magnetic separation for CR solution. The kinetics and isotherm of adsorption process are studied via a UV–visible spectrophotometer. The adsorption process is found to fit the pseudo-second-order kinetic model and Freundlich isotherm model better. Moreover, the adsorption capability of CR on Ni (1-x) Mn x Fe 2 O 4 has a great enhancement by the appropriate doping of Mn 2+ ions. In order to research the mechanism of the CR adsorption process, the effect of pH value and the surface group of the samples and CR are measured. Due to the doping of Mn 2+ ions, the surface activity of Ni (1-x) Mn x Fe 2 O 4 has been changed and the adsorption capability (231.74546 mg g −1 ) of CR on Ni 0.98 Mn 0.02 Fe 2 O 4 is maximum in the all samples at pH 5. This research suggests that appropriate doping of Mn 2+ ions could enhance the adsorption performance for CR, which provides a new idea for the development of adsorbent. [ABSTRACT FROM AUTHOR]

Carbon nanofibers (CNFs) have high specific surface area and great electrochemical stability as the anode materials for alkali metal batteries. However, they also have many defects such as low specific capacity and excessive voltage hysteresis, which hinder their wide application. In this work, Cr/S co-doped CNFs (Cr/S@CNFs) are successfully synthesized via electrospinning technique combined with high temperature treatment. As the anode for lithium ion batteries (LIBs), the Cr/S@CNFs electrode exhibits excellent cycle stability (291.7 mAh g−1 at 2 A g−1 after 900 cycles) and high rate performance (221.3 mAh g−1 at 10 A g−1). Moreover, the electrode also obtains the discharge capacity of 266.2 mAh g−1 after 100 cycles at 0.1 A g−1, showing good ion storage capacity for sodium ion batteries (SIBs). Such outstanding electrochemical performances attribute to the co-doping of Cr and S elements, presenting a reliable and efficient approach for the synthesis of high-performance anode materials. • Cr, S co-doped carbon nanofibers were obtained by electrospinning. • Cr, S co-doped induce defects in carbon nanofibers, and the properties of carbon fibers were optimized. • The Cr/S@CNFs electrode showed excellent performances for Li+/Na+ storage. [ABSTRACT FROM AUTHOR]

A series of Al-doped Li 1+x Ni 0.5 Al x Mn 1.5-x O 4 cathode materials for lithium ion batteries are successfully synthesized via a co-precipitation method. Raman spectroscopy studies reveal that the cation-disordered tends to increase with the content of Al. The data of X-ray photoelectron spectroscopy (XPS) depth profiles reveal that the inert Al 3+ ions segregates preferentially to the surface during the synthesis process. The results of the electrochemical tests suggest that the substitution of a small amount of Al has the ability to improve the rate capability of LiNi 0.5 Mn 1.5 O 4 spinel with conventional electrolytes. Especially, the Al-doped (x = 0.06) sample delivers a long cycle-life at high rate (20 C). The enhanced performance is attributed to the formation of Al-enriched surface, providing a more stable interface with the electrolyte at high voltage (∼4.7 V), along with the stabilization of the spinel structure with a disordering of the cations and improved Li-ion diffusion, based on results of the potentiostatic intermittent titration technique. [ABSTRACT FROM AUTHOR]

Sm-doped TiO 2 nanorods are synthesized by a molten salt method. The expansion of lattice parameters of Sm-doped TiO 2 samples verified by XRD and TEM characterizations suggests the successful incorporation of Sm ions into TiO 2 matrix. M-H loops show weak room temperature ferromagnetism in Sm-doped samples. Sm and N co-doped TiO 2 nanorods are also prepared to study the magnetic behaviour. The results indicate that the co-doping does not enhance the room temperature ferromagnetism but leading to a strong paramagnetic signal at 5 K. [ABSTRACT FROM AUTHOR]

The transparent ZnGa 2 O 4 glass-ceramics doped with Mn2+/Cr3+ ions were prepared by a one-step crystallization method. The visible light fluorescence properties of Mn2+ ions in 6-coordination and 4-coordination environments and the visible light fluorescence properties of Mn2+/Cr3+ ions co-doped in transparent ZnGa 2 O 4 glass-ceramics were studied. The results manifest that in the parent glass, Mn2+ ions mainly occupy the network former in the form of Hexa-coordination, and the luminescence center can emit orange-yellow light at ~600 nm. In transparent ZnGa 2 O 4 glass-ceramics, Mn2+ ions and Cr3+ ions appear at the four-coordination site (Zn site) and six-coordination site (Ga site) in ZnGa 2 O 4 spinel, respectively, and they can radiate green (510 nm) and red light (688 nm), respectively. An energy transfer mechanism of Mn2+→Cr3+ exists in ZnGa 2 O 4 : Mn2+/Cr3+ and different colors of luminescence can be produced by changing the molar ratios of components and test conditions. CIE results show that Mn2+-single-doped parent glass and glass-ceramics can be used in orange-yellow and green light displays, while Mn2+/Cr3+ co-doped transparent ZnGa 2 O 4 glass-ceramics can be used as ideal materials for the green and red light displays. • Mn2+/Cr3+ co-doped transparent ZnGa 2 O 4 glass-ceramics were successfully prepared. • The results show that Ga/Zn/O/Cr/Mn elements highly enrich in ZnGa 2 O 4 nanocrystals. • The luminescence of Mn2+/Cr3+ in this work is affected by the coordination field. • Mn2+/Cr3+ co-doped ZnGa 2 O 4 glass-ceramics can be used in multicolor display devices. [ABSTRACT FROM AUTHOR]

The Yb3+/Ho3+/Tb3+ co-doped Na 2 O-Y 2 O 3 -SiO 2 system transparent glass-ceramics containing oxyapatite-type Na 3 YSi 2 O 7 (NYS) crystals were prepared. The structure of the crystal was characterized by XRD and TEM. The most suitable heat treatment process was confirmed by DSC and TEM results. The strongest emission peak in the fluorescence spectra relates to the Tb3+: 5D 4 →7F 5 transition. In the CIE chromaticity diagram, the luminescence is concentrated in the green area. The emission intensity of the glass-ceramic is increased by 7 times compared with the precursor glass. The increase in emission intensity is caused by the entry of rare-earth ions into the Na 3 YSi 2 O 7 grains to replace the positions of Y3+ ions. The fluorescence properties of the glass-ceramics containing Na 3 YSi 2 O 7 crystals were tested at different temperatures. It is demonstrated that the luminescent materials show good thermal stability. The obtained glass-ceramic would be a candidate material for green diode elements. • TThe Yb3+/Ho3+/Tb3+ co-doped SiO 2 -Y 2 O 3 -Na 2 O parent (PG) glass was prepared. • Glass-ceramics (GC) containing Na 3 YSi 2 O 7 crystals are obtained by two-step heat-treatment. • Emission intensity of Tb3+ in transparent GCs containing Na 3 YSi 2 O 7 is 7 times that of PG. • Luminescence properties of Tb3+ in transparent GCs containing Na 3 YSi 2 O 7 show good stability. [ABSTRACT FROM AUTHOR]

The rapid capacity fading of spinel LiMn 2 O 4 cathode materials still suffers from Jahn-Teller effect and Mn dissolution. Herein, various spinel LiMn 1.90- x Ni 0.10 B x O 4 cathode materials with truncated octahedron morphology are obtained by a solid-state combustion method. Owing to the substitution of Ni-B dual-doping for Mn, the MnO 6 octahedron in the LiMn 2 O 4 generates a contraction that leads to the increased average Mn oxidation state and the suppressed Jahn-Teller effect. Simultaneously, the expansive LiO 4 tetrahedron is conducive to boosting the fast Li+ diffusion. Moreover, the growth of {110} crystal planes in the LiMn 1.90- x Ni 0.10 B x O 4 (x = 0.02–0.15) is also restrained by the Ni-B co-doping, hence alleviating the Mn dissolution. So the Ni-B co-doping accompanied with truncated octahedron morphology presents the preferential growth of {111} and {100} planes. Among the various counterparts of Ni-B co-doping, the optimized LiMn 1.84 Ni 0.10 B 0.06 O 4 exhibits the optimal rate performance and cycle life. At 5 C, a capacity retention of 73.5% with an initial discharge capacity of 101.8 mAh g−1 is achieved after ultra-long 2000 cycles. Even at 10 C, the capacity retention of 62.2% is also maintained after 2000 cycles. This combination of element doping and morphology regulation will provide a feasible strategy to synthesize high-performance spinel LiMn 2 O 4 cathode materials for lithium-ion batteries. [Display omitted] • Ni-B co-doping combined with truncated octahedron morphology. • Ni-B co-doping restrains Jahn-Teller effect and truncated octahedron morphology alleviates Mn dissolution. • The capacity retention of LiMn 1.84 Ni 0.10 B 0.06 O 4 is 73.5% after 2000 cycles at 5 C. [ABSTRACT FROM AUTHOR]

Hydrogen evolution via dye-sensitized photocatalytic water reduction is a promising approach for storing solar energy due to high efficiency and good stability. The hydrophilic and electrical performances of sensitized matrix are critical for the reactant adsorption and photogenerated charge transport. Herein, theoretical simulation proves that the boron-doping nanoarchitectonics on three-dimensional carbon nanosheets (B-3DCNs) as a new-style sensitization matrix possesses a strong water adsorption capacity to show a stable disperse in water, as well as optimizes charge distribution to improve conductivity compared with pure material. So the boron dopants on the substrate surface can be used as an anchor for water and a booster for charge transfer. Based on the theoretical results, B-3DCNs with abundant and stable boron atoms is prepared by a solid-phase thermal doping technology using sodium borohydride as boron source. The hydrophilic and electrical properties of B-3DCNs is greatly optimized using a series of structural and performance testing, providing the prerequisite for large-scale applications in aqueous solution. Therefore, the constructed B-3DCNs/Pt photocatalyst displays a high photocatalytic hydrogen evolution rate under visible light in Eosin Y sensitized system, which is 5.9 and 2.3 times than the H 2 evolved over bare Pt and 3DCNs/Pt. [Display omitted] • B-3DCNs possesses high H2O adsorption energy and predicts superior hydrophilicity. • B dopants in 3DCNs lattice tune electronic structure and facilitate charge transport. • B-3DCNs is synthesized by solid-phase thermal doping method using NaBH4 as B source. • Stable DS-PHE activity of B-3DCNs/Pt is 2.3 times than the H2 evolved over 3DCNs/Pt. [ABSTRACT FROM AUTHOR]

LiRGe 2 O 6 :xMn 4+ (R = Al or Ga) (0 ≤ x ≤ 1.0 mol%) phosphors are synthesized by solid-state reaction method in air, and their crystal structures, luminescence properties, and fluorescence lifetimes are investigated. Their photoluminescence (PL) bands peaking at ∼ 670 nm owing to the 2 E → 4 A 2 transition of Mn 4+ ion cover the region from 620 to 750 nm (λex = 289 nm), and photoluminescence excitation (PLE) bands (λem ≈ 670 nm) are observed in the range of 200–550 nm. With excitation 289 nm, PL intensity of LiAlGe 2 O 6 :0.6%Mn 4+ phosphor is far stronger than that of LiGaGe 2 O 6 :0.6%Mn 4+ phosphor owing to the influence of crystal field. The optimal Mn 4+ ions concentration is ∼0.6 mol%. The fluorescence lifetime and quantum efficiency of LiAlGe 2 O 6 :0.6%Mn 4+ and LiGaGe 2 O 6 :0.6%Mn 4+ phosphors are ∼1.55 ms, 68.5 μs, 32%, and 15%, respectively. Luminous mechanism, the temperature quenching mechanism, and the influence of crystal field to luminous properties are analyzed and discussed, respectively. The experiment results are helpful to develop other novel Mn 4+ -doped phosphors. [ABSTRACT FROM AUTHOR]

Large and heavily Ho 3+ -doped BaY 2 F 8 single crystals were grown by the Czochralski method. X-ray powder diffraction was applied to analyze the phase of the crystal samples. Simultaneously , metallographic microscope, scanning electron microscopy and energy dispersive spectrometer were employed to observe and investigate defects in the as grown crystals. Two significant kinds of defects, namely cracking and impurities were discovered in the samples of Ho 3+ :BaY 2 F 8 single crystals. Theoretical analyses suggested that mechanisms concerning the formation of the impurities such as bubbles and inclusions were considered to be closely related to the growth temperature and atmosphere while the former defect was primarily brought by the lattice distortion relating to the thermal stress and the impurities. Based on the results of experiments and theoretical analyses, the parameters of growth process were optimized and a crack free 20 mol% Ho 3+ :BaY 2 F 8 single crystal has been successfully obtained. Furthermore, the UV–Vis-IR (0.2–10 μm) absorption spectra of BaY 2 F 8 single crystal and the crystal heavily doped with Ho 3+ ions (20 mol%) have been investigated at room temperature. [ABSTRACT FROM AUTHOR]

A series of lithium and fluorine substituted Li 1+ x Ni 0.5 Mn 1.5 O 4 − x F x (0 ⩽ x ⩽ 0.4) spinel powders have been synthesized by a solid-state method. The effects of LiF content on structural, electrochemical and thermal properties are extensively investigated. The XRD patterns show that impurity arises when x ⩾ 0.3. FTIR results indicate that the cation disordering degree increases with an increasing in content of the co-doping with Li and F. The LiF concentration is optimized in the range of 0.06 ⩽ x ⩽ 0.2 in which the cyclic stability and rate capability of the Li 1+ x Ni 0.5 Mn 1.5 O 4 − x F x spinels are significantly improved. Moreover, TEM images reveal that co-doped (Li + and F − ) particles form a smooth and uniform surface film, which mitigate the interaction of active materials and electrolyte solution as well as improve cycling stability. Besides, the thermal property of the co-doped (Li + and F − ) LiNi 0.5 Mn 1.5 O 4 can effectively suppress the exothermic reaction according to the DSC results, which improve the thermal stability of the spinel material. [ABSTRACT FROM AUTHOR]

Ho/Yb-codoped Ba 0.77 Ca 0.23 TiO 3 ferroelectric ceramics were prepared by a solid-state reaction method. Under the excitation of 980 nm, all the samples exhibited strong green, red and near-infrared upconversion emissions. Upconversion emission intensities of the Ho/Yb-codoped Ba 0.77 Ca 0.23 TiO 3 ferroelectric ceramics can be enhanced with moderate Yb addition. Additionally, optical temperature sensing properties based on the upconversion emissions of the Ba 0.77 Ca 0.23 Ti 0.975 Ho 0.005 Yb 0.03 O 3 ferroelectric ceramics were also investigated. The result demonstrated that the optical temperature sensor can be operated in the temperature range of 93–300 K with a maximum sensitivity of about 0.0053 K −1 at 93 K. Compared with other rare-earth doped materials, it is much easier and cheaper to synthesize Ho/Yb-codoped Ba 0.77 Ca 0.23 TiO 3 ferroelectric ceramics. [ABSTRACT FROM AUTHOR]

To investigate the Yb 3+ doping effect on the upconversion emissions and temperature sensing properties of the Er 3+ doped smart ferroelectric ceramics, (Ba 0.85 Ca 0.15 ) 0.994− x Zr 0.1 Ti 0.9 O 3 –0.006Er 3+ / x Yb 3+ ( x = 0, 0.005, 0.01, 0.015, 0.025 and 0.035) have been synthesized by the conventional solid-state reaction process. The results illustrate that the ferroelectric and piezoelectric properties decrease with the increment of Yb 3+ doping content. The green and red upconversion emission intensities of the ceramics excited under 980 nm increase with the increasing Yb 3+ content and achieve the maximal value at x = 0.015. Based on the fluorescence intensity ratio of green emissions at 525 and 550 nm, the temperature sensing properties of the optimized composition of the prepared ceramics ( x = 0.015) were studied. The ceramics as temperature sensing materials can be operated in a wide temperature range of 173–573 K, and the maximum sensitivity achieves 0.0068 K −1 . It was demonstrated that the comprehensive temperature sensing properties achieved here is better than the previous reported results based on the same technology. [ABSTRACT FROM AUTHOR]

Cu-doped AlN (Cu:AlN) thin films were deposited on non-ferroelectric substrate (Si (1 1 1)) and ferroelectric substrates (LiTaO 3 and LiNbO 3 ) by direct current reactive magnetron sputtering. It was discovered that all the deposited Cu:AlN thin films showed room temperature ferromagnetism and the average magnetic moment (AMM) per Cu atom of the film increased with the decrease of the angle ( θ ) between AlN film plane and the c -axis of ferroelectric substrate. A giant AMM as high as 2.23 μ B /Cu was obtained when Cu:AlN thin film was deposited on LiTaO 3 (110) with θ of 0 degree, while a small AMM of about 0.11 μ B /Cu was observed when Cu:AlN thin film was deposited on LiNbO 3 (0 0 6) with θ of 90°. It was discovered that the AMM of the film increased with decreasing of θ . The ferromagnetism modulation was ascribed to the coupling between AlN piezoelectric film and ferroelectric substrate, resulting from the change of host lattice structure and spontaneous polarization of AlN thin film. The in-plane anisotropy of AMM and the annealing relaxation results confirmed the anomalous coupling. [ABSTRACT FROM AUTHOR]

Al-doped Ti 3 SiC 2 powders were synthesized by solid state reaction under a vacuum atmosphere. Results showed that Al doping effectively improved the purity of the as-prepared Ti 3 SiC 2 powders which had a narrow particle size distribution. The complex permittivities and reflection loss of Ti 3 SiC 2 samples were determined in the frequency range of 8.2–12.4 GHz. It was found that 20% Al-doped sample showed the greatest values in the real part ε ′ and imaginary part ε ″ of complex permittivity and the better reflection loss with an absorbing thickness of 2.1 mm. The mechanism of dielectric loss by Al doping was discussed. [ABSTRACT FROM AUTHOR]

Highlights: [•] BCT-B ceramics have obvious aging effect, however, no effect in BCT-A. [•] The aging effect in BCT-B is induced by the ordered defect dipoles. [•] Aging in BCT-B enhances the Q m and T c, degenerates the piezoelectric response. [ABSTRACT FROM AUTHOR]

Highlights: [•] The soft magnetic properties of Ni80Fe20 films with Tb dopants up to 8.4% are kept. [•] The different mechanisms of FMR linewidth are separated and studied. [•] Magnetic anisotropy constants, Lande g factor, etc. are discussed quantitatively. [•] The Gilbert damping is increased by more than 50 times with 8.4% of Tb dopants. [ABSTRACT FROM AUTHOR]

Highlights: [•] Ferromagnetism enhancement of Cu-doped AlN films via defect engineering. [•] Carbon implantation introduces defects into Cu-doped AlN films. [•] Ferromagnetism strongly correlate to engineered defects in Cu-doped AlN films. [•] Defects both encourage the trapping of electrons and interaction between BMPs. [ABSTRACT FROM AUTHOR]

Highlights: [•] F/Sn and Al co-doped ZnO thin films were synthesized by sol–gel method. [•] The co-doped nanocrystals exhibit good crystal quality. [•] The origin of the photoluminescence emissions was discussed. [•] The films showed high transmittance and low resistivity. [ABSTRACT FROM AUTHOR]

Abstract: Lead-free (1− x)Na0.5Bi0.5TiO3–xBa(Zr0.05Ti0.95)O3:Pr (NBT–xBZT:Pr, x =0–0.12) were synthesized by conventional solid state method. The influence of Ba(Zr0.05Ti0.95)O3 (BZT) content on the piezoelectric and photoluminescence performance was investigated. The results show that all ceramics exhibit strong red emission at 607nm, and the NBT–0.07BZT:Pr ceramic shows the optimal photoluminescence property. In addition, piezoelectric performance is also enhanced with the increasing of BZT fraction, and reaches the maximum value at x =0.07. The results show that the Pr3+ ions emission may be used as a probe for the phase transition of the ferroelectric materials. [Copyright &y& Elsevier]

To combat the thermal quenching and inadequate sensitivities of luminous materials, the Y 1.98–2 x W 3 O 12 :0.02Er3+/2 x Yb3+ (YWO:Er3+/2 x Yb3+; 0.01 ≤ x ≤ 0.11) microparticles with splendid negative thermal expansion (NTE) effect were designed. Excited at 980 nm, the produced samples emit polychromatic upconversion (UC) emissions triggered by the energy back transfer from Er3+ to Yb3+ and it has been systematically discussed via steady-state rate theory. The thermally enhanced UC emissions are accomplished in YWO:Er3+/2 x Yb3+ microparticles due to the distinctive NTE properties. Moreover, according to the temperature-associated UC emissions of Er3+ arising from its thermally coupled levels (TCLs) and non-thermally coupled levels (non-TCLs), the thermometric properties of synthesized microparticles are investigated. When non-TCLs are adopted, the absolute and relative sensitivities of resultant microparticles are 0.0129% and 1.7875% K−1, respectively. Furthermore, through manipulating doping content and spatial mode, the temperature sensing capacities of YWO:Er3+/2 x Yb3+ microparticles are multi-dimensionally regulated. In addition, contactless temperature recognition can also be realized through analyzing the thermochromic features of final products and its relative sensitivity is 2.1604% K−1. Ultimately, visual optical temperature detection is obtained in designed microparticles via its temperature-related emitting colour. Our findings may provide an important insight into the design of luminescent materials with high sensitivities for multi-mode visual optical thermometry. [Display omitted] • YWO:Er3+/2 x Yb3+ microparticles possess good NET and UC emission properties. • Thermally enhanced UC emissions are accomplished in studied samples due to the NTE effect. • The thermometric behaviors of resultant microparticles can be multi-dimensionally tuned. • Based on color coordinates, the maximum S r value of final compounds is 2.1604% K−1. • The prepared samples are potential candidates for multi-mode visual optical thermometry. [ABSTRACT FROM AUTHOR]

The optoelectronic properties and film-formation characteristics of CuCrO 2 are optimized through oxygen (O) and nitrogen (N) co-doping using the space-limited domain annealing method in ambient air. After O, N co-doping at 100 °C, the conductivity of CuCrO 2 is enhanced due to a decrease in trap-state density and an increase in hole concentration, thereby facilitating carrier transport. With a work function (W F) of 5.24 eV and an electron affinity (χ) of 2.29 eV, the CuCrO 2 films serves as both a hole transport layer (HTL) and an electron-blocking layer, playing a pivotal role in enhancing photogenerated holes extraction while suppressing nonradiative charge recombination at the heterojunction interface. Consequently, the responsivity and detectivity of the device with FTO/TiO 2 NRs/O, N co-doped CuCrO 2 /Au structure reach 188 mA W−1 and 3.14 × 1013 cm Hz1/2 W−1 in self-powered mode, respectively. Simultaneously, the rise/decay time is reduced to just 31.2/32.1 ns. Furthermore, after applying a bias of − 2 V, the photodetector demonstrates significantly improved performance with a responsivity of up to 5 × 105 mA/W (365 nm, 0.97 mW cm−2) and an apparent quantum efficiency of ∼30,000%. These results highlight the promising potential of utilizing O, N co-doped CuCrO 2 HTL for constructing high-performance optoelectronic devices. • An innovative self-powered ultraviolet photodetector composed of TiO 2 nanorod arrays/CuCrO 2 is developed using an all-solution process technique. • The optoelectronic properties and film-formation characteristics of CuCrO 2 are optimized through O and N co-doping using the space-limited domain annealing method in ambient air. • By adjusting the energy band alignment of the heterojunction, nonradiative charge recombination was mitigated, resulting in enhanced device performance. • Significant excellent performance, e.g., R = 188 mA W−1 @ 0 V, D λ * = 3.14 × 1013 cm Hz1/2 W−1, R = 5 × 105 mA W−1 @ −2 V (365 nm, 0.97 mW cm−2), AQE= 30,000% (−2 V, 365 nm), was achieved for self-powered ultraviolet photodetectors with TiO 2 NRs/O, N co-doped CuCrO 2 heterosturcture. [ABSTRACT FROM AUTHOR]

Thermoelectric performances of p type and isoelectronically doped CdTe are investigated using first principles method and Boltzmman transport theory. For the supercell Cd 32 Te 32 , when one N atom is doped into it, the maximal S and Z e T are only 156 μV/K and 0.76, respectively, but the Z e T values are much smaller at 300–700 K for P, As and Sb dopings. However, if eight Sr atoms are further doped into Cd 32 Te 31 M (M= pnicogen) to substitute Cd atoms, all the four maximal S values exceed 242 μV/K, and the Z e T reaches 1.5 at 1000 K for N doping, but for P, As and Sb dopings the values do not exceed 1.0. The large S arises from the steep but low DOS at E F . The enhancement in Z e T results from the S dominating over σ/κ e . The number and distribution of Sr atoms have an impact on the Z e T values. Adding one or two O atoms further can hoist the Z e T at 700 K and 800 K significantly. When one Cl atom and one Na atom are doped into Cd 24 Sr 8 Te 31 N, the Z e T reaches 1.7 at 1000 K. The results show that hole doping combined with heavily isoelectronic doping is efficient on improving the electronic figures of merit of semiconductors if appropriate doped elements are chosen. The way of doping assumed here should be applicable for other semiconductor systems. [ABSTRACT FROM AUTHOR]

The hydriding reaction kinetics of cerium-lanthanum alloys was investigated using a pressure-volume-temperature (PVT) method combined with hot-stage microscopy. The H 2 consumption rate and hydride area approximately followed an exponential growth model during the initial hydriding period. The H 2 consumption rate was found to be proportional to the hydride area and the square root of the H 2 pressure. The hydriding kinetics varied among the alloys. The hydriding rate was clearly enhanced by doping with La (0–5%), which was reflected by the decreased induction time, increased H 2 consumption rate and increased hydride nucleation rate. Raman spectroscopy and theoretical analysis results suggested that oxygen vacancies may play important roles in the hydriding process. [ABSTRACT FROM AUTHOR]

Silicon-based materials have been recognized as one of the most promising anode materials for next-generation lithium-ion batteries (LIBs) due to its high theoretical specific capacity (4200 mA h g−1), appropriate lithiation potential and abundance in earth. However, the fulsome volume swell and intrinsically low conductivity result in the sluggish kinetics and the limited cycle life, which severely hinders its commercial application. Herein, a composite of Si@hollow nitrogen-doped carbon (Si@HNC) with typical yolk-shell structure is designed and fabricated via a facile strategy coupled super-molecular self-assembly with carbonization. Benefiting from the buffering effect of yolk-shell nanostructure on the volumetric variation, and the excellent conductivity of the porous nitrogen-doped carbon shell, Si@HNC anode material exhibits high structural stability, fast charge and ion transfer. As a result, the Si@HNC sample with the Si content of 54.4 wt% delivers a reversible capacity of 865 mA h g−1 with the retention of ∼98 % at 1.0 A g−1 after 300 cycles. More surprisingly, a stable capacity of 1013 mA h g−1/3.24 mAh cm−2 is also retained at 0.5 A g−1 after 400 cycles even under the high areal loading of 3.2 mg cm−2. An elaborated composite of Si@hollow nitrogen-doped carbon (Si@HNC) with typical yolk-shell structure was well-designed and fabricated via a facile strategy coupled super-molecular self-assembly with carbonization for durable and practical Li-storage applications. [Display omitted] • A scalable strategy combining supramolecular self-assembly and carbonization is proposed. • The yolk-shell structure of Si@HNC accommodates the volume expansion of active Si. • The conductive shell can significantly improve the electron conductivity and ion shuttling. • The closed shell could efficiently eliminate the contact between the Si yolk and the electrolyte. • The Si@HNC anode exhibits practical application (3.24 mA h cm−2 at 0.5 A g−1 after 400 cycles). [ABSTRACT FROM AUTHOR]

Rational designing of efficient bifunctional oxygen electrocatalysts is significantly important but rather challenging for rechargeable zinc-air batteries. Herein, a novel high-performance bifunctional oxygen electrocatalyst for rechargeable zinc–air batteries are constructed based on bimetal Mn@Co-N-C encapsulated in in situ grown N,S-doped graphitic carbon framework with within a porous three-dimensional (3D) structure. The final catalyst shows a high half-wave potential of 0.89 V for oxygen reduction reaction, and a low operating overpotential of 0.38 V to achieve a 10 mA cm−2 current density for oxygen evolution reaction. The physical characterizations reveal that a strong synergetic coupling between bimetal Mn@Co-N-C and S dopant can effectively increase the active sites, meanwhile achieve a rational manipulation of the active site configuration toward a favorable electronic structure. Impressively, the assembled zinc–air batteries using liquid electrolytes and the all-solid-state batteries with this catalyst exhibit excellent charging–discharging performance, long lifetime, and high flexibility. [Display omitted] • The second metal source is Mn, which utilizes a controlled self-assembly method to orient on N, S-doped carbon-based materials generated from MOFs. • The synthesized Mn@Co-NS catalyst exhibits excellent bifunctional electrocatalytic activity. • The reasons for the superior performance of Mn@CO-NS catalysts are revealed. • Mn@Co-NS has good performance and long-term stability in the field of zinc-air batteries. • It provides direction guidance for the qualitative landing of various metals on carbon substrates, bringing the application of zinc-air batteries to a new level. [ABSTRACT FROM AUTHOR]

We carried out both the experimental and theoretical investigations on the synthesis and photocatalytic performance of the visible-light responded, W and N co-doped NaTaO 3 powders. The nanocubic NaTa 1− x W x O 3− x N x ( x = 0.00, 0.01, 0.03, 0.05, 0.1) particles with a range of 100–200 nm in size have been successfully synthesized at 700 °C via the NaOH flux reaction method. The microstructure, chemical composition and optical absorption of the as-prepared photocatalysts were discussed in detail. The photocatalytic performance of as-prepared powders was evaluated by decolarization of rhodamine B (RhB) under visible light irradiation with the wavelengths longer than 400 nm. The optical band gap of NaTaO 3 could be significantly reduced through the co-doping of W and N. The degradation efficiency of RhB over the NaTaO 3 with co-doping of W and N in the charge-compensated mode was remarkably improved. Furthermore, the first-principle calculations were also performed to discover the effects of co-doping of W and N on the electronic structure of NaTaO 3 . These present results provide a simple and feasible route to design new photocatalysts based on NaTaO 3 or other oxide photocatalysts. [ABSTRACT FROM AUTHOR]

Hierarchical Mo-doped S/BiOCl (MSB) heterostructures were successfully prepared by a facile one-step reflux method. The resulting samples were evaluated by XRD, SEM, TEM, DRS and XPS. The results obtained showed that MSB possessed an outstanding photo and/or thermocatalytic performance under near room-temperature for removal of methylene blue (MB), reaching up to 99.9 and 96.5% for photo/thermocatalytic degradation (PTD) and thermocatalytic degradation (TD), respectively. The hole/radical scavenger tests indicated holes and free radial were both participated in PTD and TD reactions, but the holes formed from degradation reactions were strongly considered as the most influential impact on conducting PTD and TD patterns rather than free radicals. Furthermore, the kinetics regarding PTD and TD routes were also monitored, preferentially fitting to Langmuir–Hinshelwood behavior. Briefly, this study may provide new insights into fabricating hierarchical heterostructures by in-suit one-step approach for decontamination of organic pollutants separately using PTD or TD. [ABSTRACT FROM AUTHOR]

(Mn, Co) co-doped BiFeO 3 /CoFe 2 O 4 (BFMCO/CFO) double-layer films were prepared on fluorine doped tin oxide (FTO)/glass substrates by the chemical solution deposition method. The effect of (Mn, Co) co-doping on crystal structure, ferroelectric and magnetic properties of BFO/CFO double-layer films was investigated. Mn and Co co-doping on the BiFeO 3 layer induced the tendency of phase transformation from rhombohedral to tetragonal. Well saturated polarization hysteresis loops were observed in BFMCO/CFO films, meanwhile a giant remanent polarization of the double-layer films ( P r ∼ 123 μC/cm 2 , after compensation) is obtained. Furthermore, an enhanced ferromagnetic behavior of M s ∼ 113 emu/cm 3 , M r ∼ 67 emu/cm 3 and H c ∼ 1200 Oe is observed in BFMCO/CFO films. The reduction of Fe 2+ and the existence of high valence iron ions with co-doping Mn and Co were confirmed by XPS. Therefore, the difference of magnetic moment of TM 2+/3+ and Fe 3+ may play a more important role in the suppression of the spiral spin modulation. As a result, the introduction of (Mn, Co) and CoFe 2 O 4 layer is an effective way to enhance the multiferroic behavior of the films. [ABSTRACT FROM AUTHOR]

In this paper, we discuss the impact of tellurium (Te) doping on the spinel superconductor CuRh 2 Se 4. We conducted a comprehensive evaluation of the structural and superconducting properties of the system using various techniques, including X-ray diffraction (XRD), resistivity, magnetization, and specific heat measurements. Based on our XRD analysis, we found that the spinel superconductor CuRh 2 Se 4- x Te x (0 ≤ x ≤ 0.28) crystallizes in the space group Fd 3 ̅ m (227), while the layered compound CuRh 2 Se 4- x Te x (2.8 ≤ x ≤ 4.0) crystallizes in the space group P 3 ̅ m 1 (164). The upper critical magnetic field can be increased from 0.95(2) T for CuRh 2 Se 4 to 3.44(1) T for CuRh 2 Se 3.72 Te 0.28 by doping with elemental Te. However, the layered compound CuRh 2 Se 4- x Te x (2.8 ≤ x ≤ 4.0) did not exhibit superconducting properties. Besides, the specific heat measurements of CuRh 2 Se 4- x Te x (x = 0, 0.1, 0.28) indicate that the Te element doping affects the electronic structure and interactions of the material and breaks the stability of the superconducting pairing, which leads to a decrease in the T c. Finally, we show the electronic phase diagram of T c with Te doping to summarise our findings. • New CuRh 2 Se 4-x Te x compounds were designed and synthesized by a solid-state method. • CuRh 2 Se 4- x Te x (0 ≤ x ≤ 0.28) adopted in spinel and all superconducting. • CuRh 2 Se 4- x Te x (2.8 ≤ x ≤ 4.0) has a layered structure but not superconducting. • The upper critical magnetic field can be enhanced by Te doping. [ABSTRACT FROM AUTHOR]

The "shuttle effect" caused by polysulfide (LiPSs) dissolution and diffusion is a great challenge for sulfur (S) cathode in lithium-sulfur batteries (LSBs). Herein, we have successfully constructed Co/CoV 2 O 6 tandem catalytic heterostructure anchored by N-doped carbon (Co/CoV 2 O 6 /NC) via an impregnation-assisted pyriaolysis method. The "adsorption-transfer-conversion" tandem catalytic mechanism for LiPSs is realized by utilizing the three behaviors of the strong chemical adsorption of CoV 2 O 6 to LiPSs, the strong conversion of Co to LiPSs, and the transport effect of CoV 2 O 6 ←Co interfacial built-in electric field to polysulfide ions. This can effectively suppress the "shuttle effect" by separating the adsorption and conversion process of LiPSs at different active sites. The tandem catalytic characteristic coupled with the interfacial Co-N and V-N bonds among Co, CoV 2 O 6 and NC, the high electrical conductivities of metal Co and NC conducting network, the hierarchical porous structure of polyhedral framework, collectively endow Co/CoV 2 O 6 /NC@S cathode with strong structural stability, weak electrochemical polarization, good electrochemical reversibility and fast electrochemical kinetics. As a result, Co/CoV 2 O 6 /NC@S cathode presents the significantly enhanced electrochemical performance with a high capacity of 558.4 mAh g−1 at 0.2 C after 100 cycles and a low-capacity decay rate of 0.123% per cycle during 300 cycles at 1 C. • Co/CoV 2 O 6 tandem catalytic heterostructure was successfully constructed. • The adsorption-transfer-conversion tandem catalytic mechanism was realized. • The shuttle effect was suppressed by separating adsorption and conversion. • A high capacity of 558.4 mAh g−1 at 0.2 C after 100 cycles was achieved. • A low-capacity decay rate of 0.123%/cycle during 300 cycles at 1 C was achieved. [ABSTRACT FROM AUTHOR]

Developing electrode materials with hierarchically porous structure and high electrochemical stability is crucial for improving the energy density of supercapacitors (SCs). Herein, the NiCoAl layered trimetallic hydroxides supported on hollow carbon shells (NCA@HCs LTHs) with various Al doping amounts is synthesized by a simple hydrothermal method. The electrode material with the optimal NCA doping ratio (mass ratio 3:2:0.3) displays a stable layered hydroxides structure and low crystallinity. Additionally, the unique 3D hollow structure not only increases the specific surface area (SSA) but also effectively prevents the agglomeration of LTHs. The synergistic interaction of these two aspects is responsible for the exceptional specific capacity and cycling performance. The optimal N 3 C 2 A 0.3 @HCs LTHs exhibits a high specific capacitance of 792 C g−1 at 1 A g−1. Moreover, the constructed asymmetric supercapacitor (ASC) achieves a coulombic efficiency of 98% and retains 80% of its capacitance after 12,000 cycles at 5 A g−1. The above results show that the synergistic strategy of Al doping and hollow structure design provides new insights into improving the electrochemical performance of SCs. [Display omitted] • The construction of NiCoAl-LTHs@mesoporous carbon core-shell hollow nanospheres. • The synergistic strategy of atomic doping and structure design facilitates performance. • The electrode exhibits a high specific capacitance of 792 C g−1 at 1 A g−1. [ABSTRACT FROM AUTHOR]

Highlights: [•] ɛ′(T) of La0.5Ca0.5MnO3 are investigated by EOM GF. [•] The intensity of ɛ′(T) reduced with the increase of |ɛJT |, V, U. [•] TP rises as |ɛJT |, V, and U increase. [•] TP remains unchanged and ɛ′(T) increased with the increase of g. [•] The calculated results of ɛ′(T) are explained theoretically. [Copyright &y& Elsevier]

• Structure, site-occupancy and luminescence of Na 3 SrMg 11 (PO 4) 9 :Eu2+/Mn2+/Tb3+ were studied. • Broad excitation band and wide-gamut-coverage emission could be achieved by tuning Eu2+/Mn2+/Tb3+ ratio. • The optimal blue/green/red phosphors exhibit high quantum efficiencies with IQE>60%. [Display omitted] A series of tricolor-emitting fifillowite-structured Eu2+/Tb3+/Mn2+-doped Na 3 SrMg 11 (PO 4) 9 (NSMP) phosphors were synthesized. Its structural parameter, luminescent properties, and energy transfer behaviors were systematically studied. The optimal NSMP: Eu2+, Tb3+/Mn2+ phosphors exhibit bright RGB emission bands, i.e. blue emission from Eu2+, while green and red emission from sensitized Tb3+ and Mn2+, respectively. Eu2+-Tb3+/Mn2+ energy transfer processes are verified as a resonant type with ET efficiency of>80%. The emitting colors of NSMP: Eu2+, Tb3+, Mn2+ phosphors could be adjusted from blue (0.156, 0.077) to green (0.322, 0.552), to red (0.667, 0.299) by increasing Tb3+/Mn2+ doping content. The internal quantum efficiency of blue NSMP:0.04Eu2+, green NSMP:0.04Eu2+, 0.40Tb3+ and red NSMP:0.04Eu2+, 1.40Mn2+ phosphor is estimated at 64.46%, 78.17% and 78.03%, respectively. A significant leap of emission thermal-stability is found in Na 3 SrMg 11 (PO 4) 9 : Eu2+ after co-activation with Mn2+/Tb3+ ions. In general, the emitting colors and energy transfer could be effectively regulated in the Na 3 SrMg 11 (PO 4) 9 host, and a general method for photoluminescence tuning is demonstrated. [ABSTRACT FROM AUTHOR]

A novel high-emissivity Cu2+-Fe3+ co-doped LaAlO 3 ceramic has been prepared by a solid-phase reaction technology at high temperature. The effect of the doping ratio (0.25 ≤ n (Cu2+)/ n (Fe3+)≤ 1.0) on the infrared radiation (IR) properties of LaAlO 3 ceramics was investigated systematically, and the mechanism of enhanced emissivity was revealed. The result shows that Cu2+-Fe3+ co-doping can substantially improve the IR performance of LaAlO 3 ceramics. In the range of 0.25 ≤ n (Cu2+)/ n (Fe3+) ≤ 0.75, the emissivity of LaAlO 3 ceramics increases steadily with the doping ratio. When n (Cu2+)/ n (Fe3+) = 0.75, the specimen has the largest emissivity of 0.83 and 0.82 in the 1.0–2.5 µm and 2.5–14 µm bands respectively, achieving an enhancement of 315% and 116% than pure LaAlO 3. The improved IR properties of Cu2+-Fe3+ co-doped LaAlO 3 ceramics can be attributed to enhanced impurity energy level absorption, free carrier ion absorption and lattice vibration absorption. These high emissivity Cu2+-Fe3+ co-doped LaAlO 3 ceramics are non-toxic, non-hazardous and low-cost, exhibiting promising application potential in the field of energy-saving for thermal equipment. • Cu2+-Fe3+ co-doped LaAlO 3 ceramic was synthesized via solid-phase reaction method. • The maximum emissivity in 1.0–2.5 µm and 2.5–14 µm of Cu2+-Fe3+ co-doped LaAlO 3 were 0.83 and 0.82. • Cu2+-Fe3+ co-doped LaAlO 3 ceramic has significant application prospects for energy-saving of thermal equipment. [ABSTRACT FROM AUTHOR]

Layered double hydroxides (LDH) are regarded as promising electrode materials for supercapacitors due to their abundance, multiple oxidation states, and high theoretical capacitance. However, the limited active sites and dull reaction kinetics restrict their commercialization. In this work, the 3D hierarchical N-doping ZnCo-LDH array on nickel foam (NF) as an electrode material (N-ZnCo-LDH) was designed and directly fabricated via a hydrothermal method using 2-Methylimidazole as a nitrogen source. Consequently, the N-doping confined the growth of the N-ZnCo-LDH to form ultrathin nanosheets, which exposed more redox reaction active sites and facilitated the charge transfer, resulting in the enhancement in charge storage capacity. As a result, the optimal N (0.5) -ZnCo-LDH achieved a high specific charge of 942.6 C g−1 at 1.0 A g−1, excellent charge-discharge rate property (68.9% retention) and long durability (84.1% after 5 000 cycles). Also, the hybrid supercapacitor (N-ZnCo-LDH//AC) was fabricated employing N (0.5) -ZnCo-LDH as anode and activated carbon (AC) as cathode, which achieved an energy density of 29.2 Wh kg−1 at a power density of 750.0 W kg−1, and excellent cycling stability (84.0% retention after 10,000 cycles), which highlighted the potential of the N (0.5) -ZnCo-LDH electrode material towards practical application of supercapacitors. [Display omitted] • The ultrathin N-doped ZnCo-LDH nanosheets were synthesized using 2-Methylimidazole as nitrogen source. • N-doping confined the growth of the nanosheets, making them smaller and thinner. [ABSTRACT FROM AUTHOR]

With the development of flexible optoelectronic devices, the research on electrode materials with high conductivity and excellent contact characteristics has received extensive attention. In this study, we successfully prepared Ag-doped Cu-Cr-Zr alloy electrode film by co-sputtering deposition on the glass and PI (polyimide) substrates, respectively. The study aimed to investigate the effect of Ag on the performance of Cu-Cr-Zr alloy electrode film for flexible optoelectronic applications. The results showed that Ag promoted the growth of the film in the direction of {111} crystal plane group and promoted the growth of more prominent grain. Moreover, doped Ag can reduce the porosity of the film. Thus, the resistivity of the film reduced from 3.18 μΩ·cm to 2.32 μΩ·cm after Ag doping. The flexible bending performance of the film was optimized, with the film's resistivity of the film increasing only 5.6% after 20k bending. Furthermore, the film retained high adhesion strength, rating 4B on the glass substrate and 5B on the PI substrate. The root mean square of the film with a thickness of about 200 nm was less than 1.3 nm which means that the alloy film had good surface morphology. The Ag-doped Cu-Cr-Zr alloy electrode film is expected to have potential applications in flexible optoelectronic devices due to its high conductivity, excellent surface, and optimized flexible bending performance. In conclusion, the Ag-doped Cu-Cr-Zr alloy electrode film prepared in this study is a promising candidate for flexible optoelectronic applications. • We studied the effect of Ag doping on Cu-Cr-Zr alloys and the performance differences with different compositions. • We focus on the conductivity, bonding strength, flexibility and surface roughness of the nano film. • We used magnetron co-sputtering technology which is a doping method from the atomic level. • We found that Ag changed the preferred texture growth and grain size of CCZ film. • The results of this study can provide further support for the performance optimization of photoelectric thin film devices. [ABSTRACT FROM AUTHOR]

Due to the advantages of abundant precursors, simple preparation, and environmental friendliness, nitrogen-doped carbon is considered one of the most potential anodes for potassium ion batteries (PIBs). Here, nitrogen-doped carbon materials (NC-2) were prepared by using secondary exfoliated g-C 3 N 4 as a precursor, combined with sucrose, and subjected to hydrothermal and high-temperature pyrolysis. NC-2 is characterized by high nitrogen content, porous layered structure, and large interlayer spacing. NC-2 used as anode of PIBs shows a high reversible capacity of 261.07 mAh g−1 at 0.1 A g−1 and an impressive rate performance of 153.36 mAh g−1 at 2 A g−1. The impressive performance of NC-2 can be originated from the porous layered structure and enlarged interlayer spacing promotes the intercalation/deintercalation and the diffusion of K ions, and the defective carbon structure formed after nitrogen doping can supply abundant active sites for K ions. The results show that NC-2 has great potential in the field of PIBs anode. [Display omitted] • Nitrogen-doped carbon derived from secondary exfoliated g-C 3 N 4 was used as high-rate anode of potassium ion battery. • The high nitrogen content and porous layered structure of the carbon are beneficial for improving the performance of PIBs. • The nitrogen-doped carbon exhibits impressive rate performance of 153.36 mAh g-1 at 2 A g-1. [ABSTRACT FROM AUTHOR]

Synthetically enhancing the recoverable energy density (W rec) and efficiency (η) is important to energy storage dielectric capacitors. ABO 3 perovskite structure material (Pb 0.96-α Ba 0.04 La α)(Zr 0.65 Sn 0.3 Ti 0.05)O 3 (PBLZST) is a typical antiferroelectric energy storage dielectric and has been widely studied due to the high polarization. But its low breakdown strength (E b) limits its further application. Many researchers focused on single-doping in PBLZST and achieved high E b or η , but synthetical enhancement is still a difficulty. In this work, we conducted A-site acceptor-donor co-doping and B-site acceptor-donor co-doping in PBLZST, respectively. Li and La were introduced into PBLZST at A-site and Nb-Mn were co-doped in PBLZST at B-site. XRD and EDS patterns suggest the pure phase of these doped samples. It is found that Li-La co-doping and Nb-Mn co-doping can both increase the breakdown strength from 156.2 kV/cm (pure PBLZST) to 304.5 kV/cm and 273.3 kV/cm, respectively. While, the W rec also respectively increases to 5.56 J/cm3 (Li-La) and 3.71 J/cm3 (Nb-Mn) from 2.97 J/cm3, suggesting a comprehensive enhancement in energy storage performance. The mechanism of the enhancement was discussed. This work can provide a strategy to regulate and control the energy storage performance. • Comprehensively enhancing energy storage performance of antiferroelectric material PBLZST. • Compensating for the lack of research on donor-acceptor co-doping in PBLZST. • Analysis of the A-site/B-site donor-acceptor co-doping effect on antiferroelectric and dielectric behavior PBLZST. [ABSTRACT FROM AUTHOR]

Abstract In this work, Fe was doped in the semiconductor Ag 2 S to form Fe-doped Ag 2 S nanocomposites (Fe-Ag 2 S NCs) for enhancing the catalytic performance of pure Ag 2 S for the first time. According to the investigation of the oxidation reaction of 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H 2 O 2 , the Fe-Ag 2 S NCs were proved to possess more excellent catalytic activity compared with that of Ag 2 S as a peroxidase mimic. Besides, the catalytic mechanism of the Fe-Ag 2 S was ascribed to the hydroxyl radical (OH) generated from the decomposition of H 2 O 2 in the catalytic oxidation process of TMB. On the basis of the excellent catalytic activity of Fe-Ag 2 S, a sensitive and efficient colorimetric sensor has been constructed for determining H 2 O 2 and this sensor has a sensitive linear response to H 2 O 2 in the range of 10–150 μM with a detection limit of 7.82 μM. All of the above confirmed that the doping of iron could really improve the catalytic activity of Ag 2 S. It is believed that Fe-doped Ag 2 S will open a new way for researchers to optimize the performance of semiconductors. Graphical abstract Image 1 Highlights • Fe-Ag 2 S nanocomposites possess the excellent peroxidase-like activity. • Fe-Ag 2 S nanocomposites were firstly applied in colorimetric sensor. • Fe-Ag 2 S nanocomposites could catalyze the oxidation of TMB in the presence of H 2 O 2. • The catalytic mechanism of Fe-Ag 2 S is based on the hydroxyl radical mechanism. [ABSTRACT FROM AUTHOR]

Abstract As an admirable candidate of thermostable LTCC materials, Bi 2 (Zn 1-x Ni x) 2/3 Nb 4/3 O 7 (0.0 ≤ x ≤ 0.5) ceramics with improved dielectric properties have been prepared via conventional mixed oxide route. Microstructure analysis manifests that the phase transition occurs from monoclinic zirconolite phase (β-BZN) to cubic phase (α-BZN) for Ni doped specimens. The crystal field theory supported the analysis of the initial phase transition processes. From the structure transformation and electrical properties test result, the Ni2+ substituted Zn2+ shows an effective method to restrain the grain growth and improve dielectric constant when sintered at 925 °C. The temperature coefficient of dielectric constant is controlled by phase composition and is found to be −6.4 ppm/°C at the two-phase coexistence region of the doping content x = 0.35. The dielectric properties of ε = 101.2, tanδ = 9.5 × 10−4 are obtained in this component. The features of the Bi 2 (Zn 1-x Ni x) 2/3 Nb 4/3 O 7 ceramics make them promising for use in high-frequency applications. Highlights • In Bi 2 Zn 2/3 Nb 4/3 O 7 system, the phase transition caused by Ni2+ was initially discussed through crystal field theory. • The correlation between phase transition and dielectric performance was established. • A good combination of dielectric properties ε = 101.2, tanδ = 9.5 × 10−4, τ ε = 6.4 ppm/°C was obtained at x = 0.35. [ABSTRACT FROM AUTHOR]

Abstract A novel Ti-doped Fe-6.5Si soft magnetic composites (SMCs) was prepared in this work. Effects of doping Ti on magnetic performances of Fe-6.5Si SMCs were investigated. The results show that only α-Fe(Si,Ti) phase can be detected in Ti-doped Fe-6.5Si particles and SMCs. After doping Ti the saturation magnetization of Fe-6.5Si powders significantly reduces and the coercivity first decreases then increases with increasing the Ti content. Ti additions can increase the electrical resistivity of Fe-6.5Si alloy. Introduction of Ti decreases the total core loss of Fe-6.5Si SMCs, among which hysteresis loss makes a greater contribution than eddy current loss. The magnetic permeability of Ti-doped Fe-6.5Si SMCs increases first then drops with the Ti content ranging from 0 to 2.0 wt %. Compared with Ti-free Fe-6.5Si SMCs, Fe-6.5Si SMCs doped with 0.5 wt % Ti shows lower core loss and higher effective permeability. Highlights • Introducing 0.5 wt% Ti into Fe-6.5Si alloy causes an obvious decline in coercivity. • Doping Ti can decrease core loss of the SMCs mainly by reducing its hysteresis loss. • Fe-6.5Si-0.5Ti SMCs shows lower P and higher μ compared with Fe-6.5Si SMCs. [ABSTRACT FROM AUTHOR]

Abstract Both magnetic transition and magnetocaloric properties of LaFe 11.6 Si 1.4 doped with boron (B) and carbon (C) were investigated. Experimental data showed that nearly pure τ 1 phase was obtained in LaFe 11.6 Si 1.4 , LaFe 11.6 Si 1.4 B 0.06 and LaFe 11.6 Si 1.4 C 0.06 alloys after annealing at 1373 K for 100 h. All annealed samples underwent a first-order magnetic transition. B doping decreased the magnetic transition temperature from 192 K to 188 K, whereas C doping increased to 206 K. In combination with X-ray diffraction results, the density-functional theory was used to reconstruct the unit-cell in order to understand the magnetic transition behavior. The results suggested that almost all B atoms occupy 96 i FeII/Si substitutional site, and all C atoms prefer 24 d interstitial site in the present given conditions. The annealed samples possessed the maximum magnetic entropy changes higher than 20 J/(kg⋅K) under a magnetic field change of 3 T, and their effective refrigeration capacities reached 200 J/kg. Highlights • Doping effects of boron and carbon on La−Fe−Si compounds were investigated. • Density-functional theory was used to reconstruct the crystallographic unit-cell. • The occupation information of boron and carbon in La−Fe−Si was clarified. [ABSTRACT FROM AUTHOR]