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In this study, SrMoO 4 :Tb3+ phosphors were successfully synthesized for a single-band ratiometric (SBR) thermometry utilizing the redshift of CTB. The SrMoO 4 :Tb3+ phosphors have a tetragonal system owing to I 4 1 /a space group and irregular microparticles possessing a mean size of 20 μm. The incorporation of Tb3+ ions into the SrMoO 4 matrix lattice leads to a reduction in the bandgap energy owing to occurrence of defects level in gap-band. Thermal quenching concentration of Tb3+ is 1%, due to the dipole-dipole interaction between Tb3+ and Tb3+ ions. This study observed an interesting redshift in the edge of the CTB with increasing temperature, which can be explained using the configurational coordinate diagram. This phenomenon can be utilized to construct this SBR temperature measurement strategy by selecting appropriate excitation peaks or bands with different thermal responses. The study also demonstrated that SrMoO 4 : 1%Tb3+ has higher S a value of 13.31 × 10−2 K−1 @573 K and S r value of 3.54 K-1@298 K in optical thermometry, making it a suitable candidate for optical temperature measurement. [ABSTRACT FROM AUTHOR]

Near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) have exhibited tremendous potential in spectroscopic technology, promoting the demand of developing novel NIR materials with excellent properties. In this paper, a series of germanate based NIR phosphors Sr 3 ZnGe 5 O 14 : xCr3+ (0 ≤ x ≤ 0.05) were synthesized by high temperature solid state reaction. The X-ray diffraction (XRD), scanning electron microscopy (SEM), Ultraviolet diffuse reflection, photoluminescence spectra and PL decay were measured to analyze the crystal structure, morphology properties and elements composition, PL emission properties and lifetimes of these NIR phosphors. Results demonstrated that phosphors Sr 3 ZnGe 5 O 14 : xCr3+ (0 ≤ x ≤ 0.05) crystallized in a trigonal with a space group of P 321(150) with a broad band gap (E g) of 4.70–4.59 eV. Sample Sr 3 ZnGe 5 O 14 : 0.03Cr3+ with the best PL emission properties showed a good thermal stability with the PL emission intensity remains 69 % of its initial value at 420 K. It's worth noting that the NIR device based on Sr 3 ZnGe 5 O 14 : 0.03Cr3+ displays an impressive electroluminescent emission stability, for example, the electroluminescent emission intensity is still about 92.3 % of its initial value when the NIR pc-LED light up for 18 h. These research results provided an important guidance for developing novel Cr3+ doped germanate based NIR phosphors with excellent thermal and electroluminescent emission stability. [ABSTRACT FROM AUTHOR]

CaMoO 4 :Pr3+ thermochromic phosphors with diverse thermal responses for temperature sensing were prepared by the traditional solid-phase reaction method. The typical CaMoO 4 :Pr3+ had scheelite structure belonging to tetragonal crystal system and space group of I 4 1 / a (88). Pr3+ ions can be easily substituted for Ca2+ ions of host CaMoO 4 because of similar ionic radius. CaMoO 4 : 1.5% Pr3+ have the block structure with mean size of 6.84 μm. The E g (∼3.93 eV) value of pure CaMoO 4 is bigger than that (∼3.65 eV) of CaMoO 4 : 1.5%Pr3+, attributing to the existence of intermediate defect energy levels. Appropriate Pr3+ doping concentration is 1.5%, and the concentration quenching phenomenon can be explained by the concrete electric multipole type of d-d interaction. The emission peak at ∼605 nm from 1D 2 →3H 4 transition have a good thermal stability of 99.452%@423 K, while the wide band centered at ∼490 nm from 3T 1,2 → 1A 1 transition in the MoO 4 2− complex and 3P 0 →3H 4 transition in Pr3+ have a poor thermal stability of 27.572%@423 K. Calculated activation energy is 0.239 eV. Temperature-dependent FIR for optical thermometry was constructed due to their diverse thermal responses. CaMoO 4 : Pr3+ phosphor had good relative sensitivities of 2.216%, 0.969% and 0.932% based on FIR of I 605 nm /I 490 nm with Boltzmann distribution, modified Boltzmann distribution and exponential equation fitting. Thermochromic behavior and thermal quenching mechanism are investigated. The obtained relative sensitivity is better than that of most phosphors, implying that CaMoO 4 : Pr3+ has a potential for application in optical thermometry. [ABSTRACT FROM AUTHOR]

The photoluminescence and temperature sensitivities of Ca 3 Y 2 Si 3 O 12 :Pr3+ thermo-phosphors with silico-carnotite structure obtained by solid state reaction method were investigated. Pr3+ ions were accommodated in the A sites having coordination number of 9 in AB 2 C 2 (SiO 4) 3 to replace Y3+ ions. The typical sample consisted of microcrystals with an irregular structure and the surface of particles was smooth, which could enhance the luminescence due to reducing the scattering and non-radiation produced by rough surfaces. The band gap value of typical sample was about 4.01 eV. Dipole-dipole interaction could account for concentration quenching. The two thermometry strategies including normalized intensities from 3P 0 →3H 4 transition and Fluorescence intensity ration (FIR) of 3P 0 →3H 4 /3P 1 →3H 5 transitions were employed for temperature sensing in 298–573 K. The results revealed that Ca 3 Y 2 Si 3 O 12 :Pr3+ thermo-phosphors had good temperature sensitivity performance with maximum S r of 0.59% K−1@573 K and 0.762% K−1@298 K in the above two methods, respectively. Hence, Ca 3 Y 2 Si 3 O 12 :Pr3+ would be a promising candidate in the field of optical thermometry. [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]

Highlights: [•] We have synthesized the layered LiNi0.5Mn0.5O2−xF x (0⩽ x ⩽0.04) by hydroxide co-precipitation method. [•] The structure, morphology and electrochemical performance of LiNi0.5Mn0.5O2 are influenced by F doping effect. [•] The cations mixing of pure LiNi0.5Mn0.5O2 decreases and Li+ diffusion coefficient increases with doping F. [•] The reversible capacity of LiNi0.5Mn0.5O1.96F0.04 is 155.0mAhg−1 after 50 cycles at 0.2 C, 0.5 C and 1.0 C ratios between 2.8 and 4.6V. [ABSTRACT FROM AUTHOR]

Highlights: [•] A new polymer (TPAFCN) as electron acceptor was designed and synthesized. [•] Photoinduced electrons transfer from MEH-PPV to TPAFCN. [•] The applied PSCs show a high V OC of about 1.0V. [ABSTRACT FROM AUTHOR]

• Egg albumin assisted sol-gel synthesis of Eu3+ doped SnO 2 phosphor. • The concentration quenching mechanism was attributed to the dipole-quadrupole interaction type. • SnO 2 : 2%Eu3+ had high relative sensitivity of 3.214 % K−1 at 298 K (2854.42/T2 K−1). • A promising phosphor for possible applications in temperature sensing. SnO 2 : Eu3+ phosphors were prepared via egg albumin assisted sol-gel method. The typical sample SnO 2 : Eu3+ had tetragonal rutile structure. The sample SnO 2 : Eu3+ had irregular lamellar structure and serious agglomeration. The optical bandgap values of samples were in the range of ∼3.92–4.36 eV. When Eu3+ concentration was 2.0 %, concentration quenching of dipole-quadrupole (d-q) interaction type occurred. Based on the non-thermally coupled energy level fluorescence intensity ratio, the sample SnO 2 : 2%Eu3+ had the maximum absolute sensitivity of ∼0.87565 K−1 at 373 K. The relative sensitivity was estimated to be 2854.42/T2 K−1, and the maximum relative sensitivity was 3.214 % K−1 at 298 K, which had great potential application in the field of temperature sensing. [ABSTRACT FROM AUTHOR]