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The fluorescent ceramic GdAG:Ce was formed by aqueous tape casting-isostatic pressing process and synthesized by high temperature solid state method. To investigate the effect of introduction of Gd3+ on the crystal structure, the photoluminescence (PL) properties, decay lifetime and the white light-emitting diodes (WLED) applications, non-Gd3+ analogue sample YAG:Ce was prepared as well. In contrast, fluorescent ceramic GdAG:Ce exhibited a relatively smaller XRD peaks, much stronger PL emission intensity and shorter lifetime than that of YAG:Ce. These findings could be beneficial to the improvement of the WLED performance. Moreover, fluorescent ceramic GdAG:Ce was made up of practical with garnet structure, which possessed good thermal stability. As a consequence, an increase of color rendering index (Ra) to 62.3 and decrease of correlated temperature (CCT) to 3208 K was achieved by the WLED device based on fluorescent ceramic GdAG:Ce. The impressive results provided a basis for the fluorescent ceramic used in the field of WLED with high Ra and low CCT. [ABSTRACT FROM AUTHOR]

Abstract: SnO2 micro/nano-structured biscuits had been successfully prepared via egg albumin-assisted sol–gel procedure. The typical sample calcined at 900 °C was pure SnO2 with a tetragonal rutile structure, constructed by the numerous pomegranate seed-like irregular nanoparticles in the range of ~100 to ~400 nm. The complexation of egg albumin and tin ions and the bonding characteristics of functional groups had been confirmed. The band gap energy values of samples were apparently higher than the reference value of bulk matter, which could be assigned to a well-known effect that small particles tended to exhibit increased band gaps. It was revealed that with the increase of the calcined temperature the photoluminescence efficiency increased. The sample at 500 °C had the higher photocatalytic activity and the higher mean photo-degradation rate of MO was 88.1 ± 1.2% as compared to other samples, which could be assigned to the lower value of band gap due to the defect levels in the band gap from the impurities formed during the growth and the lower photoluminescence efficiency, beneficial to electrons transfer and reducing the combination of electron and hole, which resulted in better photocatalytic activity.Graphical abstract: [ABSTRACT FROM AUTHOR]

The Cu 2 O/Cu hybrid composites were successfully prepared via a simple one-pot green hydrothermal method using egg albumin as structure modifier. The phase structures, surface morphologies, chemical and optical properties of the samples were characterized by using XRD, FE-SEM, FT-IR and UV–Vis spectra. The effects of egg albumin amounts, holding time and molar ratio of raw materials on product structure were studied and bonding mechanism of Cu 2 O/Cu nanoparticles with egg albumin was discussed. BET specific surface areas and BJH pore size distributions were determined from N 2 adsorption-desorption isotherms. The photocatalytic degradation of organic pollutants of the Cu 2 O/Cu hybrid composite was investigated and possible photocatalytic mechanism of Cu 2 O/Cu hybrid composites were proposed. The degradation rate of MB without any catalysts was only 3.33%, while the degradation rate of MB in the Cu 2 O/Cu+H 2 O 2 system under visible light after 80 min was as high as 87.74% and the photo-degradation reaction rate was (244.6 ± 42.0) × 10−4 min−1. H 2 O 2 and Cu 2 O/Cu composite had a synergistic action in photodegradation process of MB, which exhibited its potential as an excellent photocatalyst for degradation of MB under visible light irradiation. Image 10394 • Cu 2 O/Cu hybrid composites were prepared via a one-pot green hydrothermal method. • EA amounts and holding time played an important role in the growth of particles. • The EA was bonded with Cu 2 O/Cu nanoparticles by amide carboxylate. • The degradation rate of MB in the Cu 2 O/Cu+H 2 O 2 system was as high as 87.74%. • H 2 O 2 and Cu 2 O/Cu composite had a synergistic action in degradation process of MB. [ABSTRACT FROM AUTHOR]

Abstract The Eu3+-doped α-Al 2 O 3 micro/nano-biscuits were prepared via microwave/starch- assisted sol-gel approach. The typical sample had the pure hexagonal α-Al 2 O 3 phase. The solubility limit of Eu3+ ions was ~ 2 mol%. The micro/nano-biscuits consisted of the outer layers paved with nanoparticles of 50–70 nm and inner layers arranged with nanoparticles of 100–200 nm in a brick-upon-tile pattern. The forming mechanism was proposed. Optical bandgap values were apparently lower than that of bulk Al 2 O 3 (~ 8.7 eV), assigned to appearance of some defect levels and incorporation of impurity ions. The critical distance was ∼ 15.95 Å and ET mechanism was the d-d interaction. The integrated strength at 423 K dropped to 68% of the original value at 298 K and the E a was ~ 0.259 eV. Moreover, the CIE coordinate of the typical sample with good thermal stability was close to that of the commercial red phosphor, having promising applications in pc-WLEDs as a red-emitting phosphor. Graphical abstract fx1 [ABSTRACT FROM AUTHOR]