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Co3O4 emerges as a promising substitute in the field of anode electrode materials for the next‐generation of lithium‐ion batteries (LIBs). Nevertheless, challenges such as volumetric effects during cycling and insufficient conductivity have resulted in its subpar cycle stability, which impedes its practical application. In this study, we successfully employed a straightforward method to design and synthesize double hemispherical nano‐Co3O4/C composite materials derived from MOF‐74(Co). Benefiting from its nano‐porous structure combined with carbon materials, the resulting Co3O4/C electrode manifests outstanding electrochemical performance. Specifically, the obtained Co3O4/C electrode exhibits a notably high reversible cycle capacity (1151.9 mAh g−1 at 0.2 A g−1), exemplary rate capability, and outstanding long‐cycle performance (maintaining a capacity of 366.2 mAh g−1 at 1 A g−1 after 1400 cycles). This research introduces a novel approach for the development of innovative anode materials for LIBs. [ABSTRACT FROM AUTHOR]

• Application of multilayer Ti 3 C 2 T x in anode materials for lithium-ion batteries. • Composite modification of metal hydroxyl fluorides with multilayer Ti 3 C 2 T x. • Capacity up to 802.4 mAh g−1 at 2 A g−1 for 1000 stable cycles. • Excellent rate performance and stability at high current densities. Research into new composites to enhance the performance of lithium-ion battery electrode materials has become a trendy area of study. Cobalt-based composites are particularly prominent due to their exceptional electrochemical performance and unique physicochemical properties. Additionally, Ti 3 C 2 T x MXenes materials are anticipated to replace graphene and other carbonaceous materials since they possess an open structure and low lithium-ion diffusion barrier. In this work, we employed simple hydrothermal method to combine layered Ti 3 C 2 T x with needle-shaped CoOHF. The resulting nanosheets showed an even dispersion of CoOHF in the surface, leading to a remarkable increase in specific capacity. Furthermore, Ti 3 C 2 T x provided a higher number of lithium-ion active sites and improved the lithium-ion migration rate, while also ensuring the structure and stability of CoOHF. This composite material enables stable cycling for 1000 cycles at high current densities of 2 A g−1 and ultimately shows a large capacity of 802.4 mAh g−1 stably. Additionally, CoOHF/MXene composites display exceptional performance rate and cycling stability. This study highlights new feasible strategies for using multilayer Ti 3 C 2 T x in lithium-ion batteries, along with metal hydroxyfluorides in new, highly efficient lithium-ion battery anode materials. In this work, we employed simple hydrothermal method to combine layered Ti 3 C 2 T x with needle-shaped CoOHF. This interaction enables stable cycling for 1000 cycles at high current densities of 2 A g−1 and ultimately shows a large capacity of 802.4 mAh g−1 stably. This study highlights new feasible strategies for using multilayer Ti 3 C 2 T x in lithium-ion batteries, along with metal hydroxyfluorides in new, highly efficient lithium-ion battery anode materials. [Display omitted] [ABSTRACT FROM AUTHOR]

It is urgent and crucial to develop highly efficient broadband Near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) which are applied in tiny solid-state NIR light sources. However, a lot of NIR phosphors suffer from low quantum yield and poor thermal stability in recent years. Hereon, the solid-state reaction synthesis process was used to create a new garnet Ca 2 GdZr 2 Ga 3 O 12 :Cr3+ (CGZG:Cr3+) phosphor, which can produce a broad range emission peak at (12,437 cm-1, 804 nm) with a full width at half maximum (FWHM) of (67567 cm−1, 148 nm). At 373 °C, thermal stability was determined to be 76%, an IQE of 75% and an EQE of 26% was observed. When driving current at 150 mA and 320 mA, the device achieved the output power of 473 mW and 968 mW. The results demonstrate CGZG:Cr3+ phosphor-convert NIR LEDs have great potential for applications in night-vision and biomedical imaging NIR spectroscopy technology. • The Ca 2 GdZr 2 Ga 3 O 12 :Cr3+ is found ultra-broadband near-infrared photoluminescence with peak at 804nm.and FWHM 148 nm. • The Ca 2 GdZr 2 Ga 3 O 12 :Cr3+ near-infrared phosphors with the very high outpower 968 mW@320 mA. • The Ca 2 GdZr 2 Ga 3 O 12 :xCr3+ is promising for use in night-vision and biomedical imaging NIR spectroscopy technology. [ABSTRACT FROM AUTHOR]

A series of Ca 3 Si 2 O 4 N 2 :Ce 3+ , Tb 3+ phosphors were synthesized and their phase composition and luminescence properties were investigated. Results showed that an efficient energy transfer occurred between the Ce 3+ and Tb 3+ ions. The thermal stability of the Ce 3+ emission was dramatically enhanced upon Tb 3+ doping. The mechanism was attributed to a shift of the configuration coordinate and an increased energy barrier for thermal quenching, which resulted from the enhanced rigid structure of the host. Finally, a white light emitting diode lamp was fabricated, which exhibited excellent properties. These results indicate that Ca 3 Si 2 O 4 N 2 :Ce 3+ , Tb 3+ can serve as promising blue-green emitting phosphors for w-LEDs. [ABSTRACT FROM AUTHOR]

A series of novel green emission Whitlockite-type Ca8ZnLa(PO4)7:Eu2+ and color tunable Ca8ZnLa(PO4)7:Eu2+,Mn2+ phosphors were prepared by the solid-state reaction method in a reducing atmosphere. Its crystal structure and phase composition were identified by high-resolution transmission electron microscopy, selected area electronic diffraction, X-ray photoelectron spectroscopy, and X-ray powder diffraction Rietveld refinement, and it was found to be trigonal, belonging to R-3 c(161) space group. The luminescence properties of Eu2+ singly doped and Eu2+/Mn2+ codoped Ca8ZnLa(PO4)7 phosphors were revealed in detail. Ca8ZnLa(PO4)7:Eu2+ is excitable over a broad range from 200 to 450 nm with a prominent green emitting. With varied Eu2+/Mn2+ ratios, fine-tune emission under 365 nm excitation can be achieved from green (0.221, 0.468) to magenta (0.391, 0.276), especially the warm white light (0.392, 0.352), and CCT 3500 K can be obtained by the process of energy transfer between Eu2+ and Mn2+. The ET mechanism in this system is managed via the dipole-dipole interaction with the maximum energy-transfer efficiency 82.8% based on the decay lifetime data. These results suggest that as-prepared phosphors can serve as promising candidates of UV-pumped w- LEDs. [ABSTRACT FROM AUTHOR]

A series of original tunable-luminescence phosphors K 3 Lu(PO 4) 2 : Tb3+, Eu3+ with efficient energy transfer (ET) was synthesized using a high-temperature solid-state reaction. The samples were characterized via X-ray powder diffraction, X-ray photoelectron spectroscopy, photoluminescence spectroscopy, CIE chromaticity coordinates, and fluorescence decay analysis. The energy band and density of states of K 3 Lu(PO 4) 2 were analyzed by the first-principles method. The cross-relaxation of Tb3+-doped phosphors was investigated as well. The ET from Tb3+ to Eu3+ ions, realizing through the electric dipole-dipole (d-d) interaction with a high ET efficiency of 98.36%, could be controlled principally by the Tb3+/Eu3+ doping concentration ratio, yielding the tunable emissions from green (0.293, 0.537) to orange-red (0.563, 0.367) range. Based on the obtained results, a three-phosphor-conversion white light-emitting diode (w-LED) was fabricated through the integration of a 365 nm chip and commercial blue-emitting BaMgAl 10 O 17 : Eu2+ phosphors, green-emitting SiAlON: Eu2+ phosphors, and orange-red-emitting K 3 Lu(PO 4) 2 : 0.1 Tb3+, 0.06Eu3+ phosphors. The appliance emits the white light at a suitable correlated color temperature of 3678 K and a high color rendering index of 91.4. These parameters are almost equal to those of ideal white light, which opens up the prospects for using this up-and-coming phosphor for warm w-LED applications. [Display omitted] • The energy transfer process from Tb3+ to Eu3+ was analyzed in detail. • The lattice structure and electronic properties of the host K 3 Lu(PO 4) 2 were simulated using the DFT approach in the VASP package. • A w-LED with suitable color temperature of 3678 k and high color rendering index of 91.4 were fabricated. [ABSTRACT FROM AUTHOR]

Pc -LEDs (phosphor-converted light-emitting diodes) are a relatively new generation of light sources frequently used for room lighting, backlighting, and plant development on account of numerous advantages, such as compactness, good stability, low energy consumption, and environmental friendliness. However, the absence of red-light emission limits the practical application of pc-LEDs. For example, pc-LEDs have a high correlated color temperature and a low rendering index. Here, a group of far-red emitting Mn4+-doped Ca 2 GdZr 2 Al 3 O 12 (CGZA: Mn4+) phosphors was effectively synthesized using a solid-state reaction technique at 1450 °C. The phase purity, morphology, and fluorescence properties of prepared phosphors were investigated using XRD, SEM, PL/PLE, and fluorescence decay analysis, respectively. Under a 344-nm excitation, CGZA: Mn4+ emitted high-purity far-red light with a peak at approximately 702 nm. Phosphor quenching was observed once the Mn4+ concentration reached 0.3 mol%. The concentration quenching mechanism of Mn4+in the CGZA matrix resulted from electric dipole-dipole interactions. An important result was that the PL band was well superposed on the absorption bands of phytochromes Pr and Pfr. The PL intensity was 50% of the initial value at 373 K. These experimental results demonstrated the board application potential of the prepared phosphors for plant breeding. • Mn4+ is found to show far red photoluminescence in Ca 2 GdZr 2 Al 3 O 12 host for the first time. • A discussion is given on the luminescent properties of Mn4+ ion in Ca 2 GdZr 2 Al 3 O 12 host. • The Ca 2 GdZr 2 Al 3 O 12 :xMn4+ far-red phosphors are promising for use in plant cultivation lighting. [ABSTRACT FROM AUTHOR]

NaSrNbO lead-free piezoelectric ceramics were prepared by the sol-gel method, they were sintered at different temperatures with or without protective atmosphere. The influences of sintering temperature and protective atmosphere on the characterization and properties of the ceramics were investigated. All the ceramics showed the pure tungsten bronze structure and an intermediate relaxor-like behaviour between normal and ideal relaxor ferroelectrics according to the modified Curie-Weiss law. The sintering temperature affected significantly the properties of ceramics, with the sintering temperature increased both with and without protective atmosphere, the ε, d, K and P of these ceramics initially increased and decreased finally, whereas the variation of Q and E showed the opposite tendency. Furthermore, the protective atmosphere also significantly affected the properties of these ceramics, ε, d, K and P of such ceramics sintered with protective atmosphere were superior to those of the ceramics sintered without protective atmosphere, while the tan δ, Q and E gave the contrary results. [ABSTRACT FROM AUTHOR]

NaSr2Nb5O15 piezoelectric ceramics were sintered at different temperatures with or without atmospheric powder. The effects of atmospheric powder and sintering temperature on the dielectric, piezoelectric, and ferroelectric properties of the ceramics were analyzed. According to the modified Curie-Weiss law, we know that all these ceramics show an intermediate relaxor-like behavior between the normal and ideal relaxor ferroelectrics. Atmospheric powder affects significantly the properties of ceramics because the ceramics sintered without atmospheric powder lose lots of sodium. Furthermore, sintering temperature also significantly affects the properties of ceramics because the relative density of ceramics is enhanced when sintering temperature is increased. [ABSTRACT FROM AUTHOR]

Highlights: [•] Pure LiTaO3 powder was synthesized at 500°C by a molten salt technique. [•] Pure polycrystalline LiTaO3 ceramics prepared by a pressureless sintering method. [•] The ceramics annealed at 1300°C for 3h exhibits a Curie temperature of 663°C. [•] The as-prepared LiTaO3 ceramics have good ferroelectric properties. [ABSTRACT FROM AUTHOR]

Abstract: Al2O3–SiC–C refractories are widely used in the steelmaking process due to their outstanding properties, and in order to improve their slag corrosion resistance, the erosion resistant materials have often been used. β-Sialon and Ti(C, N) are point out as novel additives that present suitable properties to increase the corrosion resistance of refractories. In this study, unfired Al2O3–SiC/β-Sialon/Ti(C, N)–C refractories were prepared using Ti(C, N)/β-Sialon powders, brown alumina, SiC, micro α-Al2O3 powder, silica fume, ball pitch, calcium aluminate cement, aluminum and silicon as the starting materials. The effect of the Ti(C, N)/β-Sialon powders and SiC on the slag penetration and corrosion resistance of the refractories was investigated, and the slag resistance mechanisms of the Al2O3–SiC/β-Sialon/Ti(C, N)–C refractories were also discussed. Fractal theory, scanning electron microscopy (SEM) and energy dispersive spectroscope (EDS) were carried out in order to better understand the slag resistance effects and reaction mechanisms. The results showed that all samples made with Ti(C, N)/β-Sialon powders had excellent slag corrosion resistance. The slag corrosion resistance of the samples was based on their low apparent porosity and high volume density. The β-Sialon and SiC powders contributed to the improved slag corrosion resistance performance of the composite refractories. [Copyright &y& Elsevier]

Thermal quenching is one of the most critical challenges for the application of materials under high temperatures. Particularly, BaMgAl 10 O 17 :Eu2+ (BAM) has been well considered the preferred blue-emitting phosphor in tricolor fluorescent lamps, plasma display panels (PDP), and many other lighting and display devices due to its excellent luminescence efficiency and satisfactory chromaticity. However, its wide application range is still constrained by two major problems. Firstly, the synthesis temperature for BAM is too high. Commercial BAM materials are typically prepared with high-temperature solid-phase methods over 1550°Ctemperatures. Secondly, co-solvent, which is added during the synthetic process to dissolve the solid phases, is prone to thermal deterioration. To tackle these problems, we propose the cationic substitution method combined with co-solvent-assisted sintering to improve the thermal stability of BAM. In the end, we obtained a novel BAM material with a comparably lower synthesis temperature and satisfactory thermal stability. In our work, the thermal stability of BAM synthesized with 5% boric acid substituted by 0.08 mol Ca2+ was significantly higher compared with that synthesized without calcium substitution. Additionally, the activation energies (Δ E) of Ba 0.92 Ca 0.08 MgAl 10 O 17 :Eu2+ and Ba 0.92 Sr 0.08 MgAl 10 O 17 :Eu2+ were calculated to be approximately 0.26 eV and 0.35 eV, respectively, indicating that the BAM substituted with Sr2+ is more thermally stable. • Cationic substitution combined with co-solvent assisted sintering method is used to decrease the thermal deterioration. • The synthesis temperature of the as-prepared materials is reduced by nearly 300°, which can save a lot of energy consumption and cost for production. • By replacing Ba2+ with Ca2+ and Sr2+,the luminescence intensity of the fluorescent sample was greatly improved. [ABSTRACT FROM AUTHOR]

Summary: In this study, we synthesized a bimetal hydroxyl fluoride, Co0.6Zn0.4(OH)F, with an overlapping nanoneedle structure using a simple hydrothermal method. The synthesized Co0.6Zn0.4(OH)F was used as a new electrode material to study its electrochemical performance. Because of the synergy between Co and Zn and the high ionicity of fluorides, the Co0.6Zn0.4(OH)F electrode exhibited a discharge capacity of 1355.5 mAh g−1 during the first charging and discharging cycle. After 400 cycles at a current density of 2 A g−1, the Co0.6Zn0.4(OH)F electrode showed an excellent specific capacity of 756 mAh g−1. The Co0.6Zn0.4(OH)F electrode also exhibited an excellent capacitance contribution rate, indicating good rate performance. In addition, the hydroxyl and oxygen vacancies in the electrode material promoted the lithium/dilithium reactions. Therefore, Co0.6Zn0.4(OH)F is an excellent lithium storage material with high rate; thus, it has a certain potential application value in the future. [ABSTRACT FROM AUTHOR]

• Novel single-phase Ca 8 ZnGd(PO 4) 7 :Eu2+,Mn2+ phosphors have been prepared. • The energy transfer process from Eu2+ to Mn2+ was analyzed in detail. • The colour tuneable emission was obtained. • A systematic emission colour tuneability from green to white were observed. The Eu2+ activated Ca 8 ZnGd(PO 4) 7 :Eu2+ green light emitting phosphors and Eu2+/Mn2+ co-doped tunable light emitting phosphors Ca 8 ZnGd(PO 4) 7 :Eu2+,Mn2+ were successfully synthesized via the solid-state reaction method. The X-ray powder diffraction measurements and Rietveld refinement were used to assess the phase composite and crystal structure. The photoluminescence properties, diffuse reflection spectrum, chromaticity coordinates and fluorescence decay curves of the samples were investigated. It has been confirmed that the resonant type Eu2+→Mn2+ energy transfer occurs via a dipole-quadrupole interaction. With various Eu2+/Mn2+ molar ratios, the spectrum-tunable phosphors are obtained from green (0.183, 0.335) to white (0.297, 0.298). [ABSTRACT FROM AUTHOR]

Currently, the application potential of Cr3+ doped near-infrared (NIR) fluoride phosphors excited by blue light is promising. However, the development of near-infrared fluoride phosphors with wider emission bandwidth remains a challenge. Herein, we employed the hydrothermal method to prepare K 2 NaCrF 6 :Fe3+ phosphors. Upon excitation at 432 nm, the K 2 NaCrF 6 :xFe3+ phosphors exhibited broad near-infrared emission, with the main peak ranging from 752 nm to 780 nm. As the Fe3+ concentration increased, the luminescence intensity of the K 2 NaCrF 6 :xFe3+ phosphor decreased, accompanied by a redshift in the emission band and an increase in the full width of the emission spectrum half-peak. These changes can be attributed to the dipole-dipole interaction, specifically the energy transfer between Fe3+ and Cr3+, leading to the 4T 2 (4F) → 4A 2 (Cr3+) and 4T 1 (4G) → 6A 1 (6S) (Fe3+) transitions. • K 2 NaCrF 6 :Fe3+ phosphors display application potential for near-infrared (NIR) fluorescence when excited by blue light. • The developed phosphors exhibit a broad near-infrared emission bandwidth (752–780 nm) under 432 nm excitation. • Increasing Fe3+ concentration leads to redshift and broadening of the emission spectrum. • Luminescent changes are attributed to dipole-dipole interactions and efficient energy transfer. • Cr3+ and Fe3+ enables synchronous excitation processes, offering versatility for applications in spectroscopy. [ABSTRACT FROM AUTHOR]

Due to its high theoretical capacity (4200 mAh g−1), appropriate charging potential (∼0.5 V vs Li+/Li), and abundant raw material sources, silicon anode material is considered to be an ideal anode material for lithium-ion batteries. However, its low intrinsic conductivity and huge volume expansion (∼300%) during the lithiation process seriously reduce the cycle life of the battery, causing the battery's capacity to rapidly decay. In this work, 3D pomegranate-like structured Si@void@Ni@C microspheres are designed and synthesized through hydrothermal and carbonization methods. In this unique structure, the supporting layers, including carbon and nickel layers, can not only improve conductivity but also offer sufficient space to alleviate the volume expansion of silicon particles during the lithium insertion/extraction process. Combined with the above advantages, the 3D pomegranate-like structured Si@void@Ni@C microspheres anode shows excellent electrochemical performance, such as high first discharge capacity (1697 mAh g−1), fine cycle stability (0.23% capacity attenuation rate for each cycle), and excellent rate performance (97.7% capacity recovery rate). [ABSTRACT FROM AUTHOR]

Owing to the high theoretical capacity, low density, and low electrochemical reaction potential of lithium metal, it is utilised as a negative electrode material in batteries, signifying its substantial potential for next-generation energy storage systems. However, the generation of lithium-metal dendrites diminishes battery life and compromises safety, representing a significant challenge in lithium-metal battery technology. This study demonstrates that a Cu-based metal–organic framework–aramid cellulose–MXene (CuMOF–ANFs–MXene) composite separator, with its enlarged specific surface area and enhanced pore structure, helps impede the formation of lithium dendrites. Notably, the Li–Cu battery with the CuMOF–ANF–MXene separator exhibits a discharge capacity retention rate of ∼98.8% after 400 cycles at 1 mA cm−2. Furthermore, Li–Li batteries employing the same separator can maintain low hysteresis for 2000 h at this current density. These findings illustrate that the CuMOF–ANFs–MXene composite separator not only inhibits lithium dendrite formation but also increases the cycle stability and cycle life of the battery. The three-dimensional porous mesh structure of the CuMOF–ANFs–MXene separator offers a novel avenue for the practical application of lithium-metal batteries. • Three-dimensional porous mesh separator is an effective means to inhibit the growth of lithium dendrites. • Aramid cellulose and MXene compounds contribute to enhancing the mechanical properties of CuMOF separators. • The new CuMOF-ANFs-MXene separator can prolong battery life and enhance battery cycling stability. [ABSTRACT FROM AUTHOR]

A series of new apatite phosphors Ca5.95−xSrxLa4(SiO4)2(PO4)4O2:0.05Eu2+ (x = 0‐5.95) were prepared with the solid‐state method. The variations of the occupation rate and cell parameters were investigated in detail, demonstrating that the phosphors are pure phases and that the different occupation rates of La3+, Ca2+, and Sr2+ ions are due to the different electrostatic bond strengths. The reflectance and photoluminescence excitation spectra prove that the phosphors can be efficiently excited with near‐ultraviolet (n‐UV) light. The broad redshift (50 nm) in the photoluminescence spectra is attributed to the increase in the crystal field splitting when the Ca2+ ion is replaced by the larger Sr2+ ion. At 150°C, the obtained phosphors maintain an emission intensity of ~67%‐77% of that at room temperature (25°C), which indicates relatively the high performance of apatite phosphors in the temperature‐dependence experiment. Because of the substitution of the small Ca2+ ion by the large Sr2+ ion, the emission color changes from green to yellow. Finally, a series of self‐made light emitting diodes lamps were fabricated by coating the Ca5.95−xSrxLa4(SiO4)2(PO4)4O2:0.05Eu2+ phosphors with commercial blue and red phosphors on an n‐UV chip (λex = 370 nm). The self‐made white‐emitting lamps display a continuous changing correlated color temperature (4053‐9353 K) or commission international de L'eclairgae (from [0.29, 0.28] to [0.38, 0.37]), implying that the series apatite phosphors have great potential to meet the different requirements of applications. [ABSTRACT FROM AUTHOR]

Phosphor is the decisive material in white light-emitting diodes (WLED), affecting light quality. Silica phosphate has good stability, low cost and environmentally friendly features, so it has great application potential. In this paper, a self-activated reddish-orange phosphor Ca 3 Gd 7 (PO 4)(SiO 4) 5 O 2 : x Sm3+ was prepared by the high-temperature solid-phase method. The phase purity of the sample was verified by X-ray diffraction (XRD). The Rietveld refinement method was used to resolve further the sample structure and the location of the substitution of rare earth ions. The photoluminescence properties were studied in detail using fluorescence spectra, temperature-dependent emission spectra and other characterization methods. The electron transition and energy transfer processes of Gd3+ in Ca 3 Gd 7 (PO 4)(SiO 4) 5 O 2 were analyzed. The fluorescence decay curve of the sample was obtained, which belongs to the double exponential curve, and the decay lifetime depending on the Sm3+ doping concentration was calculated. Furthermore, a WLED device was assembled, and warm white light was obtained, with a spectrum showing characteristic red emission, proving to complement the missing red component of commercial WLEDs. These results indicate that Ca 3 Gd 7 (PO 4)(SiO 4) 5 O 2 : x Sm3+ phosphor has great potential for application. • The reddish-orange-Emitting phosphor Ca 3 Gd 7 (PO 4)(SiO 4) 5 O 2 : x Sm3+ was obtained via the high-temperature solid-state method. • The structure of Ca 3 Gd 7 (PO 4)(SiO 4) 5 O 2 : x Sm3+ phosphor, including the incorporation sites of Sm3+, were investigated. • The mechanism of energy transfer in the luminescence process of samples was studied. • The optical properties of Ca 3 Gd 7 (PO 4)(SiO 4) 5 O 2 : x Sm3+ reddish-orange-emitting phosphor were investigated carefully. [ABSTRACT FROM AUTHOR]

Cr3+ doped phosphor shows great potential for near-infrared (NIR) light-emitting diodes (LED), but it suffers from low quantum efficiency and poor thermal stability. Herein, a novel Cr3+ doped broadband NIR garnet Ca 3 Sc 2 Ge 3 O 12 phosphor was developed. The multisite structure of the emission band is investigated by site-selective spectroscopy and is attributed to the octahedral Cr3+ perturbed by defects. Moreover, we propose different strategies to enhance the luminescence of the phosphor, including enhancement of crystallinity and elimination of defects. Compared with the initial sample, the emission intensity of the optimized phosphor is improved for 8.6 times. The optimal Ca 3 Sc 2 Ge 3 O 12 : 0.06Cr3+ phosphor exhibits excellent thermal stability. At 423 K, the integral emission intensity of the optimal sample remains 94.7% of that at room temperature. Finally, high-performance NIR LED was fabricated using a blue LED and the title phosphor. The packaged LED lamp has high radiance (109.3 mW@300 mA) and photoelectric efficiency (15.96%@40 mA). Our study not only provides a boulevard for enhancing the luminescence of Cr doped NIR phosphor, but also gives a new perspective for understanding the multisite luminescence of Cr3+ in garnet host. • Novel Cr3+ doped Ca 3 Sc 2 Ge 3 O 12 near-infrared phosphor was reported. • Different strategies were proposed to enhanced the luminescence of Ca 3 Sc 2 Ge 3 O 12 : Cr3+ phosphor. • The fabricated NIR LED has high photoelectric efficiency and is promising for use as smart NIR light source. [ABSTRACT FROM AUTHOR]

Aluminum-nitrogen six-fold octahedral coordination, [AlN6], is unusual and has only been seen in the high-pressure rocksalt-type aluminum nitride or some complex compounds. Herein we report novel nitrides LnAl(Si4− xAlx)N7O δ (Ln=La, Sm), the first inorganic compounds with [AlN6] coordination prepared via non-high-pressure synthesis. Structure refinements of neutron powder diffraction and single-crystal X-ray diffraction data show that these compounds crystallize in the hexagonal Swedenborgite structure type with P63 mc symmetry where Ln and Al atoms locate in anticuboctahedral and octahedral interstitials, respectively, between the triangular and Kagomé layers of [SiN4] tetrahedra. Solid-state NMR data of high-purity La-114 powders confirm the unusual [AlN6] coordination. These compounds are the first examples of the '33-114' sub-type in the '114' family. The additional site for over-stoichiometric oxygen in the structure of 114-type compounds was also identified. [ABSTRACT FROM AUTHOR]

A series of apatite solid solution phosphors Ca2+xLa8−x(SiO4)6−x(PO4)xO2:Eu2+ (x = 0,2,4,6) were synthesized by a conventional high-temperature solid-state reaction. The phase purity was examined using XRD, XPS and XRF. The crystal structure information, such as the concentration, cell parameters and occupation rate, was analyzed using a Rietveld refinement, demonstrating that the Eu2+ activated the Ca2La8(SiO4)6O2 and Ca8La2(PO4)6O2 to form continuous solid solution phosphors. Different behaviors of luminescence evolution in response to structural variation were verified among the series of phosphors. Two kinds of Eu2+ ion sites were proved using low temperature PL spectra (8k) and room temperature decay curves. The substitution of large La3+ ions by small Ca2+ ions induced a decreased crystal field splitting of the Eu2+ ions, which caused an increase in emission energy from the 5d excited state to the 4f ground state and a resultant blue-shift from 508 nm to 460 nm. Therefore, with the crystal structure evolution, the emitted color of the series of phosphors could be tuned from green to blue by adjusting the ratio of Ca/La. [ABSTRACT FROM AUTHOR]

Phosphors are regarded as the crucial functioning part of white light-emitting diodes (WLEDs). Silicate-based phosphors have enjoyed numerous attentions for decades due to their varied crystal structures and high chemical stability, as well as their great application potentials. In this work, a novel cyan-emitting phosphor Ba 2 La 8 (SiO 4) 6 O 2 :Eu2+ is synthesized via a high-temperature solid-state method. The phase purity was first verified by X-ray diffraction (XRD) analyses, and its structure was further solved by Rietveld refinement. The photoluminescence characteristics were investigated in detail by employing diffuse reflectance spectroscopy (DRS), fluorescence spectroscopy, and other characterization methods. The results evidence that the optimal doping concentration of Eu2+ is ∼4 mol%. The fundamental band gap of Ba 2 La 8 (SiO 4) 6 O 2 :4mol%Eu2+ is estimated to be approximately 2.91 eV, which provides sufficient space to accommodate activators like Eu2+. The CIE coordinates lie in the cyan region, which allows Ba 2 La 8 (SiO 4) 6 O 2 :Eu2+ to efficiently fill into the missing cyan emission in conventional WLED devices. As a proof-of-concept experiment, a prototype WLED device was then assembled, which suggests that the introduction of Ba 2 La 8 (SiO 4) 6 O 2 :Eu2+ could lead to an increased color rendering index from 87 to 92. These results imply that the Ba 2 La 8 (SiO 4) 6 O 2 :Eu2+ phosphors show great potential in full-spectrum WLEDs application. • The novel cyan-emitting phosphor Ba 2 La 8 (SiO 4) 6 O 2 :Eu2+ was obtained via a typical high-temperature solid-state method. • The structure of Ba 2 La 8 (SiO 4) 6 O 2 :Eu2+ phosphor, including the incorporation sites of Eu2+ into the host, were investigated. • The optical properties of Ba 2 La 8 (SiO 4) 6 O 2 :Eu2+ cyan-emitting phosphor were investigated carefully. • Thanks to the additional cyan component from the Ba 2 La 8 (SiO 4) 6 O 2 :Eu2+, the color rendering index of the WLED has boosted. [ABSTRACT FROM AUTHOR]

A series of semi-alicyclic poly(amic acid) varnishes designed for potential applications as the alignment layers for thin-film transistor driven liquid crystal display devices (TFT-LCDs) were prepared from an alicyclic dianhydride, norbornane-2-spiro-α- cyclopentanone-α′-spiro-2″-norbornane-5,5″,6,6″-tetracarboxylic dianhydride (CpODA) and aromatic diamines. Then, the liquid crystal (LC) minicells were fabricated by using the polyimide (PI) as the alignment layers, which were prepared by thermally dehydrating the PAA varnishes at elevated temperatures. The derived PI alignment layers exhibited good thermal stability with the 5% weight loss temperatures higher than 470 °C. In addition, the PI layers showed excellent optical transparency with the transmittances higher than 94.0% at the wavelength of 550 nm with a thickness around 100 nm. The LC cells fabricated with the CpODA-PI alignment layers exhibited good optoelectronic features. The rubbing PI layers could induce the effective alignment of the LC molecules with the pretilt angles in the range of 1.62–2.14°. The voltage holding ratios of the LC cells were higher than 92.00%, and the residual direct voltage values were all lower than 300 mV. [ABSTRACT FROM AUTHOR]

Abstract: Fe–Sialon–Ti(C,N) composite materials were first synthesized via carbothermal reduction–nitridation reaction with low-priced mineral materials, such as ilmenite, quartz, aluminum dross and coke powders, as starting materials. Effects of temperatures on the phase compositions and microstructures of products were investigated. The investigation results indicated that the optimal synthesis temperature was 1550°C. Rise in synthesis temperature was beneficial for the synthesis of Sialon and Ti(C,N). The as-fabricated Fe–Sialon–Ti(C,N) composites were used as additives to produce taphole clay refractories, and the bending strength and erosion resistance against blast furnace slag of taphole clay refractories were studied. Taphole clay refractories with 20wt% Fe–Sialon–Ti(C,N) composite materials still owned good slag resistance. Bending strength of taphole clay refractories increased with the addition of Fe–Sialon–Ti(C,N) composite materials; when 15wt% Fe–Sialon–Ti(C,N) composite materials were added, bending strength reached its highest value of 13.36MPa. [Copyright &y& Elsevier]

Tuning the components and multiple activator sites possesses profound significances on the regulation for corresponding luminescent properties of target phosphors. However, it is still challenging to realize full-visible emission via single activator in a single phase owing to the matrix diversity and uncertainty for multi-site occupation. Herein, we developed a family of whitlockite-type solid-solution phosphors Ca 8 MgGa 1- y La y (PO 4) 7 : Eu2+(y = 0–1) via inducing the La3+ ions into Ca 8 MgGa(PO 4) 7 :Eu2+. The local environments of Eu2+ ions and corresponding tunable photoluminescent properties, decay times and thermal stability are revealed systematically in detail. Specially, the excitation and emission spectra of Ca 8 MgGa 1- y La y (PO 4) 7 : Eu2+ are broadened gradually, finally towards a full-visible emission with 152 nm bandwidth spectrum for the phosphor Ca 8 MgLa(PO 4) 7 : Eu2+. WLED with a high color rendering index (CRI = 95) and low color temperature (CCT = 3764 K) was fabricated based on the full-visible emission Ca 8 MgGa 0.2 La 0.8 (PO 4) 7 : 0.08Eu2+ phosphors under a 365 nm chip, indicating the prominent potentials for high-color-rendering WLEDs. These results in current work provide new ideas for synergetic manipulation of components and multiple activator sites towards a full-visible emission in single-phase applied for white lighting. • Designed solid-solution phosphors CMGL:Eu2+ via incorporating Ga3+ and La3+ ions. • Full-spectrum emission (400–700 nm) achieved with single Eu2+ dopants. • Diverse Eu2+ sites enable bandwidth expansion and color tuning. • The targeted CMGL:Eu2+ phosphor optimizes the performance of WLED. [ABSTRACT FROM AUTHOR]

Abstract: β-Si3N4 powder was synthesized via carbothermal reduction nitridation (CRN) method using quartz as starting material. The influence of synthesis temperature, C/SiO2 molar ratio and amount of Fe2O3 additive on the phase transformation and micro-morphology of β-Si3N4 powder was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). The results showed that the optimal experimental conditions for the CRN synthesis of β-Si3N4 powder were 3h sintering at 1600°C in flowing nitrogen atmosphere with C/SiO2 molar ratio of 2.0 and amount of Fe2O3 additive of 5.0wt.%. The prepared β-Si3N4 grains present a short hexagonal, rod-like morphology. Changes in experimental parameters affect the phase compositions and the morphology of the product. Excessive carbon promoted the formation reaction of β-SiC. Fe2O3 additive exerted a significant promotion on the formation of β-Si3N4 in CRN process by forming the low melting point eutectics. [Copyright &y& Elsevier]

Abstract: Zircon ore carbothermal reduction with yttria addition has been carried out. The influences of heating temperature and yttria addition on the phase transformations of zirconia from zircon ore by carbothermal reduction have been investigated in detail. The phase transformations of zirconia from zircon ore by carbothermal reduction were monitored by X-ray diffraction. The microstructure and micro-area chemical analysis of the products were characterized by scanning electron microscopy and energy dispersive spectrometer. The chemical states of Zr 3d, Y 3d and O 1s presented in the products of zircon carbothermal reduction with 10 wt% yttria addition were investigated by X-ray photoelectron spectroscopy. The results showed that the optimized heating temperature of zircon carbothermal reduction with no addition was 1600 °C, and the main phase of the products consists of m-ZrO2, c-ZrO2, ZrC and β-SiC. Yttria addition could be introduced into zirconia lattice and caused it to form Y2O3 stabilized zirconia. Zirconia in the products would be turned into partially stabilized zirconia with yttria addition from 1 wt% to 5 wt% while it would exist in the form of fully stabilized zirconia with over 8 wt% yttria addition. [Copyright &y& Elsevier]

AlN-polytypoid materials are hard to be sintered and usually need a hot-pressing ( HP) technique and very high sintering temperatures (≥1750°C). In this study, densified AlN-polytypoid based composites were successfully fabricated in situ via a pressureless sintering method at a relatively lower temperature of 1650°C by compositional design. Moreover, the room temperature mechanical properties of the composites were comparable with those sintered by HP method. The results showed that 15 R-based composite was sintered via a transient liquid-phase sintering mechanism with the aid of U-phase Sialon. The pressureless-sintered composites were mainly composed of platelet 15 R, hexagonal β- Sialon, and intergranular U-phase Sialon grains, which exhibited both intercrystalline and transcrystalline fracture behaviors. Partial 15 R grains were of twin structure, which was found to be positive for toughening of the composites. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the effects of reductant addition and reaction temperature on phase behavior of serpentine by in situ carbothermal reduction nitridation (CRN) treatment were studied. A brief discussion on the synthesis mechanism of CRN process was also included. The results show that temperature and carbon content were two essential factors that determined the nitridation of serpentine and the formation of β-Si3N4 grains. Serpentine could be transformed into high-temperature composites containing Mg2SiO4, β-Si3N4, Si2N2O and β-SiC at temperatures higher than 1400°C. At 1550°C, more Si2N2O was nitrided to β-Si3N4 as the increase of carbon content, in the final products of samples with carbon addition excess 100wt.% of theoretical quantity, Mg2SiO4 coexisted with β-Si3N4 as the main crystal phases. This transformation provided a feasible way of dealing with serpentine waste for high-temperature utilization. [Copyright &y& Elsevier]

• Carbon micro- and nanofibers were prepared by using gyration. • The distribution of fiber diameter showed a normal law with 400-600 nm. • GO changes the orderly arrangement of fibers into a network structure. • The conductivity of carbon nanofibers is greatly improved by adding GO. • When GO was added, the electrode showed excellent electrochemical performance. In this paper, graphene oxide (GO) were added into polyacrylonitrile to prepare carbon nanofiber by using gyration and subsequent carbonization process as to improve their electrochemical properties. The microstructure and electrochemical properties of prepared carbon nanofiber samples were investigated by using scanning electron microscopy and electrochemical workstation, respectively. The effects of the addition amount of graphene oxide and carbonation temperature on the microstructure and electrochemical properties of composite carbon nanofibers were studied. [ABSTRACT FROM AUTHOR]

High-toughness Sialon ceramic matrix composites containing alloy second-phase particles were fabricated by hot pressing at a relatively low temperature of 1600°C. Substantially improved fracture toughness of 8.0 MPa·m1/2 was achieved through the addition of varying amounts of ferro-molybdenum alloy particles. The microstructure of the composites was characterized and crack propagation behavior was observed to understand the toughening mechanisms. The results showed that crack deflection and crack bridging are the principal mechanisms in the toughening of these types of ceramic composites. [ABSTRACT FROM AUTHOR]

Mn4+-activated fluorides have become a research hotspot in the community of inorganic red phosphors owing to their fascinating luminescent properties. However, the poor water resistance of these materials severely hinders their application in the fields of wide color gamut (CG) backlight display and warm white solid-state lighting. Herein, we propose a green, facile method, i.e. , treatment with oxalic acid (H 2 C 2 O 4) solution, for constructing a homogeneous Mn4+-rare surface shell layer to improve the water-resistant property of K 2 GeF 6 :Mn4+ (KGF) red phosphor. The moisture-resistant property of the treated KGF (T-KGF) phosphor was significantly enhanced; however, no significant change was observed in its luminescent properties. Furthermore, the reasons for the excellent water resistance of T-KGF were investigated in detail, and the formation mechanism of Mn4+-rare surface shell layer was proposed simultaneously. Results indicated that the Mn4+-rare surface shell layer was in situ deposited on the T-KGF core during the solid-liquid equilibrium process. Upon employing the as-treated T-KGF red phosphor, high-performance white light-emitting diode (WLED) with R a of 86.3, correlated color temperature (CCT) of 3824 K, high luminous efficiency (LE) of 152.37 lm/W for WLED2 and an ultrahigh CG (120.1% NTSC standard and 89.7% Rec. 2020 standard) and high LE of 103.12 lm/W for WLED3 were achieved. These results demonstrate that the proposed facile strategy may open a new opportunity to promote the commercialization of Mn4+-activated fluoride phosphors. [ABSTRACT FROM AUTHOR]

A novel g-C 3 N 4 composite photocatalyst was synthesized by one-step calcination using melamine and different functionalized multi-walled carbon nanotubes (MWCNT) as raw materials. The effect of additives on the photocatalytic performance of the composite g-C 3 N 4 has been investigated. The results showed that the incorporation of functionalized MWCNT led to a porous structure in g-C 3 N 4 , increasing the specific surface area and availability of active sites. The addition of hydroxylated/carboxylated MWCNT (HMWCNT/CMWCNT) affected the band structure of g-C 3 N 4 and reduced the band gap. The visible-light photocatalytic degradation efficiency of Rhodamine B (RhB) using g-C 3 N 4 composited with various types and amounts of MWCNT was evaluated. Among them, g-C 3 N 4 with 1 wt% CMWCNT showed the highest photocatalytic degradation efficiency of RhB and still had 92.71% photocatalytic activity after 5 cycles of degradation. • A novel composite g-C 3 N 4 with functionalized multi-walled carbon nanotubes was synthesized. • The porous structure in composite increases the availability of active sites. • The reduced band gap of the composite increases the separation rate of photogenerated electron-hole pair. • The composite exhibited 3.83-fold photocatalytic degradation efficiency with good cycling stability. [ABSTRACT FROM AUTHOR]

The ZrN‐SiAlON composite powder was synthesized using low‐grade zircon and bauxite by carbothermal reduction nitridation at first and then ZrN‐SiAlON‐SiC‐C composite refractory were fabricated with the ZrN‐SiAlON powder, SiC particles, and a small amount of Si powder as raw materials and sucrose as the binder. The slag resistance of these composites in O2, N2 and Ar atmosphere was investigated by X‐ray diffraction, scanning electron microscopy, and energy dispersion spectra. The results show that the pores in the inside of ZrN‐SiAlON‐SiC‐C composite refractory were enlarged in oxygen atmosphere due to oxidation, which leads to the decrease in slag resistance. In argon atmosphere, blast furnace slag destroyed the sintered body of zircon, corundum, and cristobalite with the formation of CaZrO3, then infiltrated into and filled the pores inside the refractory to form a dense layer, which hindered the further erosion of the blast furnace slag. In the reducing atmosphere, the interfacial energy of the gas‐liquid phases became larger due to the reactions between blast furnace slag liquid and the gas, resulting in a larger wetting angle which prevented the erosion. [ABSTRACT FROM AUTHOR]

Protein ubiquitination is essential for plant growth and responses to the environment. The SEVEN IN ABSENTIA (SINA) ubiquitin ligases have been extensively studied in plants, but information on their roles in fiber development is limited. Here, we identified GhSINA1 in Upland cotton (Gossypium hirsutum), which has a conserved RING finger domain and SINA domain. Quantitative real-time PCR (qRT-PCR) analysis showed that GhSINA1 was preferentially expressed during fiber initiation and elongation, especially during initiation in the fuzzless-lintless cotton mutant. Subcellular localization experiments indicated that GhSINA1 localized to the nucleus. In vitro ubiquitination analysis revealed that GhSINA1 has E3 ubiquitin ligase activity. Ectopic overexpression of GhSINA1 in Arabidopsis thaliana reduced the number and length of root hairs and trichomes. Yeast two-hybrid (Y2H), firefly luciferase complementation imaging (LCI), and bimolecular fluorescence complementation (BiFC) assays demonstrated that the GhSINA1 proteins could interact with each other to form homodimers and heterodimers. Overall, these results suggest that GhSINA1 may act as a negative regulator in cotton fiber development through homodimerization and heterodimerization. • GhSINA1 was highly expressed during the initiation and elongation stages of cotton fiber development. • GhSINA1 localized to the nucleus and exhibited E3 ubiquitin ligase activity. • Ectopic overexpression of GhSINA1 in Arabidopsis indicated it may act as a negative regulator in cotton fiber development. • GhSINA1 proteins could interact with each other to form homodimers and heterodimers to exert biological functions. [ABSTRACT FROM AUTHOR]

Understanding the kinetic barrier and driving force for crystal nucleation and growth is decisive for the synthesis of nanowires with controllable yield and morphology. In this research, we developed an effective reaction system to synthesize very large scale α-Si 3 N 4 nanowires (hundreds of milligrams) and carried out a comparative study to characterize the kinetic influence of gas precursor supersaturation and liquid metal catalyst. The phase composition, morphology, microstructure and photoluminescence properties of the as-synthesized products were characterized by X-ray diffraction, fourier-transform infrared spectroscopy, field emission scanning electron microscopy, transmission electron microscopy and room temperature photoluminescence measurement. The yield of the products not only relates to the reaction temperature (thermodynamic condition) but also to the distribution of gas precursors (kinetic condition). As revealed in this research, by controlling the gas diffusion process, the yield of the nanowire products could be greatly improved. The experimental results indicate that the supersaturation is the dominant factor in the as-designed system rather than the catalyst. With excellent non-flammability and high thermal stability, the large scale α-Si 3 N 4 products would have potential applications to the improvement of strength of high temperature ceramic composites. The photoluminescence spectrum of the α-Si 3 N 4 shows a blue shift which could be valued for future applications in blue-green emitting devices. There is no doubt that the large scale products are the base of these applications. [ABSTRACT FROM AUTHOR]

Carbon-encapsulated nickel particles ( Ni@C composites) for removing Fe 3+ in wastewater have been prepared by the carbonization of phenolic resin mixing with nickel particles. XRD results reveal that the Ni@C composites are consisted of C, Ni, and Ni 3 S 2 . The TG-DTG curves of Ni@C composites are almost same as that of phenolic resin. The morphology investigation shows that Ni is distributed randomly on carbon. Based on analysis of N 2 adsorption-desorption isotherm, the surface area and pore volume of Ni@C composites are 187.47 m 2 g −1 and 0.06900 cm 3 g −1 nm −1 , respectively. The saturation magnetization values for Ni@C composites are 68.99 emu·g −1 determined by the Vibrating Sample Magnetometer. Ni@C composites exhibit a high adsorption capacity for Fe 3+ . The adsorption behavior follows the pseudo-second-order kinetic and Langmuir model between the adsorbents and Fe 3+ . Furthermore, the adsorption capacity of Ni@C composites derives from the attractive force between the adsorbed anion and the surface positive charge of Ni@C composites, as well as the bond between the adsorbed cation and the COO − groups. From the above results Ni@C composites can be widely applied in wastewater treatment as a new efficiency and excellent recoverable adsorbent. [ABSTRACT FROM AUTHOR]

Carbon nanofibers were prepared by using centrifugal spinning with polyacrylonitrile as precursor. The microstructure and electrochemical properties of prepared samples were investigated by using scanning electron microscopy and electrochemical workstation, respectively. The results showed that the distribution of fiber diameter showed a normal law. The carbon fibers present good cycle stability at low scan rate. Moreover, the integral area of cyclic voltammetry curve reaches the maximum when the mass ratio of PAN/PMMA is 20:3. The specific capacitance of it is 102 F/g and 84 F/g, in case of the current density at 0.1 A/g and 0.2 A/g, respectively. [ABSTRACT FROM AUTHOR]

Aluminum-nitrogen six-fold octahedral coordination, [AlN6], is unusual and has only been seen in the high-pressure rocksalt-type aluminum nitride or some complex compounds. Herein we report novel nitrides LnAl(Si4− xAlx)N7O δ (Ln=La, Sm), the first inorganic compounds with [AlN6] coordination prepared via non-high-pressure synthesis. Structure refinements of neutron powder diffraction and single-crystal X-ray diffraction data show that these compounds crystallize in the hexagonal Swedenborgite structure type with P63 mc symmetry where Ln and Al atoms locate in anticuboctahedral and octahedral interstitials, respectively, between the triangular and Kagomé layers of [SiN4] tetrahedra. Solid-state NMR data of high-purity La-114 powders confirm the unusual [AlN6] coordination. These compounds are the first examples of the '33-114' sub-type in the '114' family. The additional site for over-stoichiometric oxygen in the structure of 114-type compounds was also identified. [ABSTRACT FROM AUTHOR]

A new family of rigid periodically zigzag structure of TiN 1 + x and columnar TiN 1 + x rods were synthesized by a vapor–liquid–solid deposition method, using iron as the catalyst and milled TiO 2 /Al powders as the starting material. Fundamental mechanism studies based on interface thermodynamics and surface tension were conducted in order to understand the formation of the near-perfect periodically zigzag structure. Four-terminal electrical measurements showed that the single crystalline rods yielded very different resistances due to their nonstoichiometric characteristics. The conductivity of the TiN 1 + x rods could be affected by insulating-type electric field. The results indicated that TiN-based nano-rods have a big potential for application in electric scopes. [ABSTRACT FROM AUTHOR]

Porous calcium hexa-aluminate (CA 6 ) ceramics have been in-situ synthesized by heating calcium hydroxide and alumina powder/aluminum hydroxide powder. The influence of aluminum source and sintering temperature on calcium hexa-aluminate grain growth and porosity was studied. A significant feature was noticed that the CA 6 grains maintained the original skeleton of aluminum source as a whole, but individual CA 6 grain formed a plate-like shape. Moreover, we proposed a three-step growth mechanism for the formation and further development of the plate-like CA 6 grains. [ABSTRACT FROM AUTHOR]

With the advancement of industrialization, developing efficient photocatalysts are needed to resolve the more serious water pollution problems. In this study, the chitin-modified and graphene oxide (GO) bridged TiO 2 /carbon fibers (CGTC) were synthesized by a facile hydrothermal treatment. The CGTC80 (adding 80 mg GO) exhibited high adsorption and higher photodegradation ability than pure TiO 2. The results shows that 50 ml of 50 mg L−1 RhB solution could be almost completely degraded (97%) in 60min. The racial trapping examination shows that the photogenerated holes (h+) is the may active species in the photocatalytic system. After 3 cycles degradation, the photocatalyst still has high photocatalytic performance (>90%). Meanwhile, the high performance of CGTC for pollutants may due to the creation of more adsorption sites by dispersion of chitin and rapid conduction of electrons effected by GO. In general, this visible-light-driven chitin-modified graphene oxide bridged TiO 2 /CF catalyst exhibits significant potential in terms of stability and reproducibility for sewage treatment applications. [ABSTRACT FROM AUTHOR]

β-SiC nanowires were synthesized by using an improved simple and low-cost thermal evaporation process at 1500 °C, without argon protect and catalyst assistant. The process simplifies the chemical vapor deposition method, which makes it easier to operate and industrialize. X-ray diffraction, Field emission scanning electron microscopy, high-resolution transmission electron microscopy and energy dispersive spectrum were employed to characterize the as-synthesized products. The β-SiC nanowires are about 50–100 nm in diameter, up to several micrometers long and usually grow along [111] direction with a thin oxide shell. A vapor–solid growth mechanism of the nanowires is proposed. [ABSTRACT FROM AUTHOR]

Phase changes of Si powder in the MgO–C refractory were investigated in a reducing atmosphere system at 1500 °C. The phase compositions, morphology and microstructures of the products were determined using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and energy dispersive spectroscopy (EDS). β-SiC nanowires were synthesized in the pores of MgO–C bricks without the assistance of catalysis. The synthesized nanowires were typically a few hundred nanometers to several micrometers in length. The formation process was governed by VS mechanism. The formed β-SiC nanowires may help to reinforce the mechanical properties and enhance the antioxidation properties of MgO–C bricks. [ABSTRACT FROM AUTHOR]

Large scale β-sialon nanobelts/nanowires and ZrN–sialon composite powders were prepared via aluminothermic reduction nitridation under different conditions with flowing N2. The phase composition, morphology, and microstructure of the as-prepared products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM/HRTEM), Fourier-transform infrared spectroscopy (FT-IR) and energy dispersive X-ray spectroscopy (EDS). The experiment results show that the phase compositions and the ratio of nanostructures to powder can be tailored by the experimental conditions. The formation of β-sialon nanostructures was dominated by a vapor–solid (VS) mechanism. The photoluminescence spectrum of the β-sialon nanostructures exhibits a special emission peak located in the violet–blue spectral range, making possible potential applications in blue-light emitting diodes and display devices. This process also provided a feasible way to prepare reinforcing β-sialon nanostructures in situ within the ZrN–sialon composite powders. [ABSTRACT FROM AUTHOR]

The effect of sintering temperature and aluminum content on the phase transformation of coal gangue by aluminothermic reduction nitridation (ARN) was investigated. The process was carried out in flowing N 2 within the temperature range of 1400–1500 °C and holding time of 4 h. The results showed that temperature and Al content were two essential factors determining the nitridation of coal gangue and the phase yields of nitrided products. Kaolinite, the main mineralogical phase of coal gangue, was transformed into high-temperature composites containing β-SiAlON, corundum and Al 6 O 3 N 4 by ARN at 1400–1500 °C. The products consisted of globular β-SiAlON/corundum particles and continuous SiAlON fibers. The transformation provided a feasible mean of dealing with coal gangue for high-temperature utilization. [ABSTRACT FROM AUTHOR]

In this paper, β-Sialon ceramic was formed with pyrophyllite as raw material and coke as reductant by carbothermal reduction and nitridation in flowing nitrogen atmosphere. Then, the erosion wear property of β-Sialon ceramic was measured. When the pre-synthesized temperature was 1400°C, the effects of carbon additions (with theoretical carbon addition and carbon in excess of 10–50wt.%) on the phase compositions of the products were studied by X-ray diffraction. β-Sialon ceramic was sintered at 1600°C, and its erosion wear behavior was examined with the use of a self-designed, liquid–solid, two-phase flow erosion equipment. Results show that the optimum carbon addition to fabricate the β-Sialon ceramic powders was in excess of 10wt% at 1400°C. Under these conditions, the pre-synthesized powders were composed of β-Sialon as the main crystalline phase and β-SiC as the secondary phase. The relationship between volume erosion amount per area of the specimens and erosion time can be explained by two exponential equations— and in two stages. [ABSTRACT FROM AUTHOR]

Silicon nitride (Si3N4) powder with tunable α/β-Si3N4 relative contents was synthesized from waste silica fume using carbothermal reduction nitridation (CRN) at a relatively low temperature range of 1400–1500°C. The effects of the carbon source, CRN temperature and raw materials ratio (Carbon-to-Silica fume) on phase assembly and micro-morphology of the products were investigated. Fabrication of α-Si3N4/β-Si3N4 from waste silica fume by CRN was achieved at temperatures as low as 1400°C. Carbon black was found to be more suitable than coke and graphite for use as the reductant. Elevated temperature was beneficial for the formation of β-Si3N4, whilst excessive carbon black promoted the formation of α-Si3N4. Thus, the α-Si3N4/β-Si3N4 relative contents could be effectively tailored by adjusting the CRN temperature and carbon concentration of the initial mixtures. In addition, the bi-modal crystals of the whiskers and the short columns strongly influenced the morphologies of the product. [ABSTRACT FROM AUTHOR]