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Abstract: Ce-coped Lu2SiO5 powders were prepared by the solid-state reaction method. The effects of flux and atmosphere on the powders structure and properties were investigated by X-ray diffraction (XRD) and spectral measurement. The XRD results show that the samples calcined at 1300°C without using flux were mainly Lu2O3, SiO2 and a small amount of Lu2SiO5, while the samples with Li2SO4 flux are mainly Lu2SiO5. Furthermore, atmosphere is little effective on powder structure. Absorption band of Lu2SiO5 powders shows five peaks at 215nm, 241nm, 275nm, 318nm and 382nm, the absorption intensity of samples prepared in air is higher than that of samples prepared in reduced atmosphere. Broad emission band and stronger emission intensities have been found in Lu2SiO5 powders prepared in reduced atmosphere. The excitation spectra of Lu2SiO5 powders prepared in reduced atmosphere are composed of four bands at 240nm, 271nm, 302nm and 360.6nm. It can be concluded that flux and atmosphere during preparation is favorable for LSO powders emission and is an effective method to decrease calcining temperature. [Copyright &y& Elsevier]

Red phosphors with good thermal stability, high color temperature and color purity are critical in high power warm white LED devices. Herein, a series of single and co-doped Tb3+,Eu3+ polychromatic phosphors with pyrochlore structure based on Gd 2 Zr 2 O 7 have been prepared for the first time by a conventional solid phase reaction method. Compared to single doped Eu3+ phosphors, Tb3+,Eu3+ co-doped phosphors possess following advantages: improved UV absorption, increased photoluminescence intensity, extended luminescence range and improved thermal stability. At room temperature, the Gd 2 Zr 2 O 7 :Tb3+,Eu3+ phosphors exhibited a gradual shift from yellow-green emission at 544 nm to orange-red emission at 613 nm with increasing doping of Eu3+ ions. Energy transfer efficiency has been evaluated to be 71% by analyzing the fluorescence lifetime of Tb3+ ions. The concentration quenching mechanism under different conditions was analyzed in detail and it was concluded that the quenching of Tb3+ is caused by dipole-dipole interaction. In addition, the activation energy (ΔE a) of the Gd 1.92 Zr 2 O 7 :0.03Tb3+,0.05Eu3+ phosphor was calculated to be as high as 0.2674 eV compared to other Tb3+, Eu3+ co-doped phosphors, demonstrating its high thermal stability. WLEDs devices based on Gd 1.92 Zr 2 O 7 :0.03Tb3+,0.05Eu3+ phosphors have been prepared, which have low correlated color temperature (CCT) (5283 K), high color rendering index Ra = 85.5 K) and CIE coordinates chromaticity coordinate (0.3371,0.3333). All of the results show that Gd 2 Zr 2 O 7 :Tb3+,Eu3+ phosphors provide a new avenue to develop high quality red emission and high thermal stability phosphors for WLEDs. • doping with rare earth ions can effectively change the band gap energy and structural of Gd 2 Zr 2 O 7 phosphor. • achieving high energy transfer from Tb3+ to Eu3+ in Gd 2 Zr 2 O 7 phosphor. • Tb3+, Eu3+ co-doped Gd 2 Zr 2 O 7 phosphor with high thermal stability. • The LED devices assembled from Gd 2 Zr 2 O 7 :Tb3+,Eu3+ have excellent chromaticity coordinate stability, high CRI and low CCT. [ABSTRACT FROM AUTHOR]

Owing to the adverse effects of tetracycline (TC) on human health, it should be completely degraded by the active species that are usually generated by photocatalysts under ultraviolet (UV) radiation. Such radiation which accounts for about only 5% energy of the sunlight. In general, obtaining the active species of the photocatalysts upon irradiation with light is challenging because of the wide spectrum of light. To address this, novel photocatalysts, La 2-x Sr x NiMnO 6 (x = 0, 0.05, 0.10, and 0.125, denoted by LNMO, LSNMO005, LSNMO010, and LSNMO0125, respectively), with high-potential valence band edge (E VB), abundant oxygen vacancies (O V -s), and narrow-energy band gap (E g) were designed and prepared via a solid-state reaction. The synthesized powders were characterized by several techniques. Sr2+ doping was found to significantly raise the E VB of LNMO and slightly increase its O V -s. The highest E VB , maximum O V -s, longest lifetime, and fastest transferring speed of the photogenerated carriers were observed for LSNMO010. It was found that LSNMO010 could effectively photodegrade TC in 240 min. TC could also undergo thermocatalytic degradation at 100 °C in 90 min in the presence of LSNMO010. However, TC could not be effectively degraded either by photolysis or thermolysis alone, in the absence of LSNMO010. It was concluded that the photogenerated holes (h +-s) and hydroxyl radicals (•OH) played dominant roles in the photodegradation of TC. Measurement of the total organic carbon (TOC) revealed that only 18.28% TOC was removed by direct photolysis, and about 83.90% TOC was mineralised by LSNMO010. The outcomes of this work suggest that introduction of dopants to increase O V and to obtain high-potential E VB in double perovskites could be a novel methodology for designing a class of narrow- E g photocatalysts that can effectively degrade TC. Image 1 • Sr-doping reduces energy band gap leading to more widened light respond range. • Sr-doping lifts valance band edge to higher potential value. • XPS analysis shows Sr-doping photocatalysts possess more oxygen vacancies. • Sr-doped photocatalyst show better catalytic ability than Sr-free photocatalyst. • Sr-doped photocatalyst also has potential to apply in degrading TC using waste heat. [ABSTRACT FROM AUTHOR]

It has been found it more difficult in completely degrading A-ring of tetracycline (TC) than completely degrading B-D rings of tetracycline. Thus, it is very necessary to find an effective route to completely degrading A-ring of tetracycline. In this work, a Z-scheme heterojuncted core-shell La(OH) 3 @BaTiO 3 composite (LB) was designed and fabricated through hydrothermal method. Many characterization techniques were employed to investigate the microstructure, phases, composition, energy band structure, and the lifetime of photogenerated carriers. In the mean time, the photocatalytic properties, including the degradation of A-ring and B-D rings of TC, as well as active species during photo-degradation were investigated. It is found that the as-prepared LB has an improved lifetime of photo-produced carriers, as well as high photocatalytic properties, being attributed to the core-shell structured heterojunction La(OH) 3 @BaTiO 3. In addition, it is also found that ·O 2 − is more effective on degrading A-ring of TC than other active species, likely owed to the PKa3 value (3.3) of A-ring in TC. This work has supplied a route to completely degrading the A-ring of TC: rationally design and prepare a Z-scheme heterojuncted composites which supply very negative conduction band bottom potential. • A Z-scheme heterojuncted La(OH) 3 @BaTiO 3 composite (LB) was designed and fabricated through hydrothermal method. • Several characterization, as well as the photocatalytic experiments have been performed on the as-prepared samples. • It was found that ·O 2 − is more effective on degrading A-ring of TC owing to the PKa3 value (3.3) of A-ring. • To degrading the A-ring of TC: design a Z-scheme heterojuncted compositeswith very negative conduction band bottom. [ABSTRACT FROM AUTHOR]

The lead sulfide (PbS) thin films with Zn doping concentration from 0 at.% to 5 at.% were synthesized utilizing chemical bath deposition technique. X-ray diffraction (XRD) revealed that the calculated crystallite size decreased from 20.6 nm to 16.7 nm with the increasing zinc doping concentration. FESEM images showed PbS nanocrystals on the surface of the films exhibited pyramidal shape, and the grain size became smaller with the increasing doping concentration. The AFM results showed that the root mean square roughness of the PbS film has been reduced due to Zn doping. The optical properties of films were explored by UV–vis–NIR spectrophotometer in the range from 400 to 2400 nm, the optical bandgap value of PbS films increased from 1.14 eV to 1.74 eV. All as-deposited films were p-type semiconducting. Among them, the 3 at.% Zn-PbS thin films possessed the lowest resistivity (10.8 Ω -cm), the highest carrier concentration (2.82 × 1017 cm−3) and carrier mobility (11.2 cm−2V−1s−1). A new ideal bandgap (1.39 eV) absorber composition (1 at.% Zn-doped PbS film) was rationally designed and facilely developed. Our work presents a promising potential for ideal bandgap absorber layer of solar cells. Image 1 • We synthesized Zn-doped PbS nanofilms with significantly improved optoelectronic properties. • The bandgap was tailored from 1.14 eV to 1.74 eV. • A new optimum bandgap (1.39 eV) absorber composition was developed. [ABSTRACT FROM AUTHOR]

To find a photocatalyst for photodegrading different pollutants, a direct Z-scheme p-n heterojunction g-C 3 N 4 /La-Bi 2 O 3 (LBOCN) composite was prepared in this study. The composite was characterized by XRD, SEM, HRTEM, UV–vis DRS, M-S, XPS, EIS and PL. The photocatalytic activity of LBOCN was evaluated by photodegrading methyl orange (MO), ofloxacin (OFX) and tetracycline (TC). Many nanodots in the as-prepared LBOCN were clearly observed in the HRTEM images, which could drastically accelerate the transfer of photogenerated charges since their size is 4–5 nm, shortening the transfer route of photogenerated carriers from the inner part to the outside. The p-n junction strengthened the Z-scheme to separate the photogenerated electrons and holes, therefore improving the photocatalytic property of LBOCN. In the photodegradation of MO, the photoreaction rate of LBOCN is approximately 13 times that of Bi 2 O 3 (BO), 12 times that of g-C 3 N 4 (CN), 3 times that of La-Bi 2 O 3 (LBO) and 2 times that of g-C 3 N 4 /Bi 2 O 3 (BOCN). Moreover, LBOCN can also completely photodegrade OFX within 60 min. Finally, this work demonstrates if a p-n-type Z-scheme heterojunction structured composite can generate superoxide radicals or hydroxyl radicals under light irradiation, the refractory antibiotics, such as ofloxacin, can be completely decomposed into small molecules under the synergistic effects of effective separation of photogenerated electron-hole pairs driven by the p-n junction and strong redox ability of the photogenerated carriers. [Display omitted] • g-C 3 N 4 /La-Bi 2 O 3 (LBOCN) is fabricated for the first time. • The HRTEM obviously demonstrated many nanodots with a diameter of approximately 4-5 nm. • MO and OFX can be completely photodegraded under the synergistic effect of Z-scheme p-n junctions and strong redox ability. • A route to select semiconductors for constructing p-n-type Z-scheme heterojunction structured composite. [ABSTRACT FROM AUTHOR]

A novel, magnetic, p – n heterojunction-structured La 0.7 Sr 0.3 MnO 3 /g-C 3 N 4 (LS/CN) photocatalyst was designed by hybridizing p -type La 0.7 Sr 0.3 MnO 3 with n -type g-C 3 N 4. Several characterizations showed that the as-preparedLS/CN-0.5 nanoparticles possessed a saturation magnetization of 27.3 emu/g, coercivity of 60.3 Oe, specific surface area of 25.68 m2/g, and average particle size of 23 nm. The photocatalytic investigation determined a degradation efficiency of 95.0% for a 100-mL tetracycline solution with an initial concentration of 50 mg/L within 210 min over 0.05 g of the LS/CN-0.5. Experiments showed that LS/CN-0.5 exhibited good reusability, where a degradation efficiency of 88.6% was obtained after six cycles. It was found that the p – n heterojunction realized the excitation of photogenerated electrons in the high-potential conduction band of La 0.7 Sr 0.3 MnO 3. Furthermore, the synergistic effects of oxygen vacancies and high-potential photogenerated electrons induced the generation of more superoxide radicals, leading to the high photocatalytic activity of LS/CN. This study demonstrates a new strategy to design and construct highly efficient, magnetic, p – n heterojunction photocatalysts. • Successfully prepared magnetic CN/LS p – n heterojunction photocatalyst. • The construction of p – n heterojunction creates more oxygen vacancies and introduces high-potential photogenerated electrons. • The synergistic effects of oxygen vacancies and high-potential photogenerated electrons induced the generation of more superoxide radicals. [ABSTRACT FROM AUTHOR]

• A novel α-SnWO 4 /UiO-66(NH 2)/g-C 3 N 4 ternary photocatalyst was prepared by solvothermal method. • The α-SW 75 /UNCN exhibits the superior photocatalytic performance for Ibuprofen degradation and H 2 evolution. • The •O 2 - and •OH are confirmed as the main reactive species. • The possible mechanism of photocatalytic was explored. [Display omitted] In this work, we successfully prepared regular hexagonal prism porous structure g-C 3 N 4 (CN), and designed α-SnWO 4 and UiO-66(NH 2) on porous CN for constructing novel ternary α-SnWO 4 /UiO-66(NH 2)/g-C 3 N 4 (α-SW/UNCN) hybrid photocatalyst by solvothermal approach. The α-SW 75 /UNCN composite showed better photocatalytic performance, and the removal rate of Ibuprofen (IPF) reached 95.5% within 2 h and the H 2 evolution efficiency reached 2105 μmol g−1 h−1 under simulated sunlight, which were 2.5 times and 21 times higher than those of α-SW (42.5% and 105 μmol g−1 h−1). The TOC removal efficiency of IPF can reach to 29%, showing higher mineralization ability compared with α-SW. In addition, the trapping experiment and ESR experiment proved that •O 2 - and •OH radicals played most important part in the photodegradation of IPF pollutants. The improved photocatalytic performance of α-SW/UNCN was owing to the construction of n-p-n type double Z-scheme heterojunction which enhanced carries separation. This work will provide a method for preparing novel and efficiency ternary composite catalyst for antibiotic contaminant degradation and H 2 production. [ABSTRACT FROM AUTHOR]

ZIF-8@TiO 2 micron composite, one kind of new high-efficiency photocatalyst was prepared by hydrothermal method in this work. We compared the ability of ZIF-8, TiO 2 nanospheres and ZIF-8@TiO 2 to catalytically degrade tetracycline. The results of the characterization show that the TiO 2 nanospheres grow uniformly on the surface of ZIF-8, and ZIF-8 and TiO 2 are linked together by chemical bonds. The synergistic effect of ZIF-8 and TiO 2 greatly enhances the catalytic ability of the composite photocatalyst. In ZIF-8@TiO 2 micron composite, ZIF-8 provides a new way for photogenerated electron transfer as a charge separator, to reduce the charge recombination rate. Since the hybrid combines the advantages of ZIF-8 and TiO 2, ZIF-8@TiO 2 exhibits excellent ability to catalytically degrade tetracycline. The possible photocatalytic mechanism of the hybrid photocatalyst was also discussed. Image 1 • ZIF-8@TiO 2 core-shell micron composite exhibits excellent photocatalytic ability and adsorption capacity. • Synergistic effect of ZIF-8 and TiO 2 can improve the photodegradation efficiency of tetracycline. • •O 2 − is the most effective active species in the mechanism for TC degradation. [ABSTRACT FROM AUTHOR]

Te doped Yttrium-aluminum (Y 2 O 3 –Al 2 O 3) system powders were synthesized by solid-state method. The structure and optical properties were investigated by XRD, SEM, XPS and PL. XRD analysis indicated that the samples transform from YAM, YAP to YAG phase as the sintering temperature rises. The samples sintered below 1200 °C have a broad emission centered at 604 nm with a lifetime up to 13.33 μs under room temperature. While in the mix phase of YAP and YAG, a sharp and intense emission peak centered at 715 nm was monitored with a lifetime up to approximate 2.76 ms. Moreover, the band structure and density of states for Te doped YAGwere investigated by first-principle calculations. [ABSTRACT FROM AUTHOR]