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A series of Ba3-x ( VO4 )2 : xSm3+ (x = 0.02-0.16) phosphors were synthesized using the molten salt method with KCl as the salt. The effects of synthesis conditions as well as Sm3+ doping concentration on the phase structure and luminescence properties of the sample were investigated in detail. The temperature sensing characteristics of the sample were also studied. The optimum reaction conditions for synthesizing the sample are calcination temperature of 900 °C, calcination time of 1h, and a mass ratio of raw materials to molten salt of 1 : 3. The obtained sample has high phase purity and crystallinity. The micromorphology of the sample is lamellar with a thickness of about 1.53 mm. Upon the ultraviolet excitation of 318 nm, the broad emission from the VO43- groups and characteristic emissions from Sm3+ can be observed simultaneously in the emission spectra of Ba3-x(VO4)2:xSm3+ phosphors, with the emission colors concentrated in the yellow-white light region. With the increase of Sm3+ doping concentration (x) from 0.02 to 0.16, the intensity of the characteristic emission peak of Sm3+ first increases and then decreases, reaching its maximum value when x =0.10. The dominant mechanism for the concentration quenching in Ba3-x(VO4)2 :xSm3+ phosphors is attributed to the dipole-dipole (d-d) interaction. Moreover, for Ba2.9 (VO4 )2 : 0.10Sm3+ phosphors, it is found that the fluorescence intensity ratio of Sm3+ (652 nm) and VO43- groups (504 nm) shows a significant temperature dependence in the temperature range of 298-473 K. Its maximum absolute and relative temperature sensor sensitivities are 0.36/K and 1.99%/K, respectively. The results indicate that Sm3+ doped Ba3(VO4)2 phosphors exhibit excellent temperature sensing performance and potential applications in non-contact optical thermometry. [ABSTRACT FROM AUTHOR]

TiO2 with different facets were prepared by hydrothermal method for photocatalytic reforming glace old to formic acid. The structural compost on and optical properties of TiO2were characterized by SEM, TEM, XRD, XPS, EPR, Raman, Ivies DRS and PL. The results showed that TiO2 synthesized vasa hydrothermal method using titanium ssopropoxide as It source and hydrofluoric acid as morphology control agent exposed (001) crystalline facets. TiO2-2F with 2 mL hydrofluoric acid add-on had coexposed anisate (001) and (101) crystalline facets and demonstrated the highest catalytic activity and selectivity. With UV light irradiation for 4 h, the conversion of glycerol over the TiO2catalyst was 49.0% and the formic acid selective was 55.6%. The interface-contacted (001) and (101) facets formed suffice heterojuncrions and improved the activactivity of photocatalytic reforming glycerol to formic acid. (001) facet with oxygen vacancy and coordination unsaturated states TiO2-Ti5l,-02c caused the deep oxidation of glycerol and tots intermediates which improved the selectivity of formic acid. Machams analyses showed that x OH and x O2 were the key active spaces for the selective ox daikon of glycerol to formic add. [ABSTRACT FROM AUTHOR]

In order to obtain films with better mechanical properties and fracture toughness, the (TiAlCrZrNb)- Six-N (x=0, 4%, 8%, 12% and 16%) high entropy ceramic nanocomposite films with different Si contents were deposited on Si substrate by magnetron sputtering technology. The effects of Si doping on the microstructure, mechanical properties! and fracture toughness of the films were investigated by X-ray diffractometry, scanning electron microscopy, high-resolution transmission electron microscopy and Nano indentation apparatus. The results show that the mechanical properties and fracture toughness of the films increase first and then decrease with the addition of Si element, which can be attributed to the formation of nanocomposite structures. When Si content is 4%, (TiAlCrZrNb)-Six-N film has the best comprehensive mechanical properties, and Us maximum hardness and elastic modulus are 22.7 GPa and 192.0 GPa, respectively. In this case, the fracture toughness reaches the best, and the radial crack length C as 6.760 µm, The K1C was 1.77 MPa • m1/2. [ABSTRACT FROM AUTHOR]

In recent years, bismuth sodium titanate (BNT)-based piezoelectric materials have shown large electro-strain response due to their unique field-induced phase transition, and have shown a great potential in actuator application. In our work, (Bio0.05Na0.05)0.935 Bao0.065 TiO3-x SrMA1O4 (x SrMA1O4, M=La, Y) lead-free piezoelectric ceramics with good electrostrain performance and temperature stability are prepared by the traditional solid-phase synthesis process. The effect of SrMA1O4 (M= La, Y) component on the phase structure and electrical properties of the ceramics is studied. The results show that the introduction of SrMA1O4 component induces a phase transformation from rhombohedral-tetragonal coexisting phases to a single pseudo-cubic phase, and destroys the ferroelectric order of the matrix material and induces the appearance of weakly polar phase. Thus, the field-induced strain is significantly imported. When the SMA content is 0.9 mol%, the material exhibit large strain response. Under a 70 kV/cm electric field, the unipolar strain is 0.39% (M = La) and 0.44% (M = Y), respectively, and the corresponding target signals d33* is 557 pm/V (M = La) and 629 pm/V (M = Y), respectively. The high strain response ta derived from the reverie transition from the ergodic relaxation state to the ferroelectric state driven by the electric field. In addition, its found that 0.9 mol% SrMA1O4 (M = Y) modified ceramic shows excellent temperature stability from room temperature to 100 °C, which ta promising for actuator applications. [ABSTRACT FROM AUTHOR]