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Co-free La 0.6 Sr 0.4 FeO 3-δ (LSFNb 0) and La 0.6 Sr 0.4 Fe 0.9 Nb 0.1 O 3-δ (LSFNb 0.1) perovskite oxides were prepared by a standard solid-state reaction method. The structural stability and electrochemical performance of La 0.6 Sr 0.4 Fe 0.9 Nb 0.1 O 3-δ as both cathode and anode were studied. Nb dopant in LSFNb 0 significantly enhances the structural and chemical stability in anode condition. At 800 °C, the polarization resistances (Rp) of LSFNb 0.1 symmetric electrode based on YSZ electrolyte are 0.5 and 0.05 Ω cm2 in H 2 and air, respectively. The peak power densities of LSFNb 0.1 based on LSGM electrolyte-supported SSOFCs are 934 and 707 mW cm−2 at 850 °C in H 2 (3% H 2 O) and dry CO, respectively. Moreover, the symmetric cell exhibits reasonable stability in both H 2 and CO fuel, suggesting that La 0.6 Sr 0.4 Fe 0.9 Nb 0.1 O 3-δ may be a potential symmetric electrode material for hydrogen and carbon monoxide SOFCs. • The substitution of Nb improves the structural stability of La 0.6 Sr 0.4 FeO 3 in H 2. • The polarization resistances of LSFNb symmetric cells are 0.5 and 0.05 Ω cm2 in H 2 and air, respectively. • The peak power densities of LSFNb symmetric cell are 934 and 707 mW cm−2 at 850 °C in H 2 (3% H 2 O) and dry CO, respectively. [ABSTRACT FROM AUTHOR]

Abstract The Mo-doped La 0.6 Sr 0.4 Fe 0.9 Ni 0.1 O 3-δ (LSFNM) material is synthesized by a sol-gel method as a SOFC anode. XRD results explain that La 0.6 Sr 0.4 Fe 0.9 Ni 0.1 O 3-δ (LSFN) is decomposed severely above 800 °C in reducing atmosphere, while LSFNM basically maintains the cubic perovskite main phase, and only a small quantity of heterophase appears. Apparently, Mo doping can improve the reduction stability of material. Meanwhile, Mo6+ effectively suppresses the reduction of the Fe4+/Fe3+ electron pair in reducing atmosphere, which enhances the electrical conductivity. In 5% H 2 -Ar, the conductivity of Mo-doped sample is increased from 0.75 to 2.8 S cm−1 at 800 °C, which is more in line with the requirement of the anode. LSFNM exhibits lower polarization resistance (R p) than LSFN in wet H 2 ; for example, the R p values of LSFN and LSFNM at 850 °C are 0.25 and 0.18 Ω cm2. The maximum power density (P max) of the LSGM-supported single cell is increased from 740 to 975 mW cm−2 in H 2 at 850 °C, and the cell exhibits reasonable stability at 700 °C for 100 h. Thus, it is rational to consider that the LSFNM is a potential material for IT–SOFC anode. Graphical abstract Image Highlights • La 0.6 Sr 0.4 Fe 0.8 Ni 0.1 Mo 0.1 O 3-δ (LSFNM) is used as anode electrode for SOFC. • Mo doping significantly improves stability in reducing atmosphere. • The conductivity of LSFNM reaches 2.8 S cm−2 at 800 °C in 5% H 2 -Ar. • LSFNM exhibits higher hydrogen oxidation reaction (HOR) activity than LSFN. • Maximum power density of 975 mW cm−2 in H 2 is obtained at 850 °C for LSFNM. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate a regrowth-free double-tapered gain-coupled distributed feedback semiconductor laser. It is designed based on periodic surface current injection to reach a high-power and single-longitudinal mode. A continuous-wave output power of over 1.2 W/facet is achieved at 4 A. High single-longitudinal-mode output power reaches up to 0.9 W/facet at 3 A at each uncoated facet. The side mode suppression ratio is nearly 30 dB at 980 nm. The 3 dB spectral width is less than 2.7 pm. The lateral far field divergence angle is only 14.5°, the beam quality factor M2 is 1.7, achieving a near-diffraction-limit emission. Our device, produced by standard i-line lithography, enhances the output power while obtaining the pleasurable spectral and spatial properties. It has great potential in widespread commercial applications such as high efficiency pumping sources for its low-cost, easy fabrication technique and excellent performance. [ABSTRACT FROM AUTHOR]

Abstract: Anatase TiO2/multi-walled carbon nanotubes (TiO2/MWCNTs) hybrid nanofibers (NFs) film was prepared via a facile electrospinning method. Dye-sensitized solar cells (DSSCs) based on TiO2/MWCNTs composite NFs photoanodes with different contents of MWCNTs (0, 0.1, 0.3, 0.5, 1wt.%) were assembled using N719 dye as sensitizer. Field emission scanning electron microscope (FESEM), transmission electron microscope (TEM), X-ray diffractometer (XRD), and Raman spectrometer were used to characterize the TiO2/MWCNTs electrode films. The photocurrent–voltage (I–V) characteristic, incident photo-to-current conversion efficiency (IPCE) spectrum, and electrochemical impedance spectroscopy (EIS) measurements were carried out to evaluate the photoelectric properties of the DSSCs. The results reveal that the energy conversion efficiency is greatly dependent on the content of MWCNTs in the composite NFs film, and a moderate incorporation of MWCNTs can substantially enhance the performance of DSSCs. When the electrode contains 0.3wt.% MWCNTs, the corresponding solar cell yield the highest efficiency of 5.63%. This efficiency value is approximately 26% larger than that of the unmodified counterpart. [Copyright &y& Elsevier]