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Al–Ni co-doped ZnO (NiAl:ZnO) thin films were deposited on glass substrates using a sol–gel method. Based on a previous study, Zn 1 − x Al x O (AZO; Al/Zn = 1.5 mol%) thin films optimized with a Ni content of 0.5 mol% were annealed at different temperatures from 450 to 600 °C in N 2 /H 2 (95/5) forming gas for 1 h. The effects of the annealing temperature on the structural, electrical and optical properties were determined. X-ray diffraction showed that NiAl:ZnO thin film annealed at 500 °C exhibited the best crystallization quality. XPS revealed the presence of metallic Ni and Ni 2 O 3 states, as well as Ni and Al atoms were successfully doped in NiAl:ZnO films, which did not result in a change in ZnO crystal structure and orientation. Scanning electron microscopy showed that the films were smooth and compact, and the grain size increased with increasing annealing temperature from ~ 23.8 nm to ~ 34.6 nm. According to the Hall Effect measurements, when the temperature reached 500 °C, the resistivity of the thin film showed the lowest value of 1.05 × 10 − 3 (Ω cm), which is the lowest resistivity reported for NiAl:ZnO films. The UV–Vis transmission spectra showed a high transmittance of more than 80% in the visible light range, and the band gap of the films was increased from 3.30 to 3.55 eV. This study showed that the annealing temperature in the forming gas is a vital factor affecting the quality of thin films. In addition, 500 °C was found to be the most appropriate annealing temperature for NiAl:ZnO films. This study provides a simple and efficient method for preparing high quality, high transparency and low resistivity NiAl:ZnO films for optoelectronic applications. [ABSTRACT FROM AUTHOR]

Abstract: We reported on the facile synthesis of N-doped multilayer graphene (N-MLG) from milk powder that uses melamine as a nitrogen-doping source with Fe2+ ions as catalytic growth agents. We showed that milk powder could be used as a precursor for large-scale N-MLG synthesis through heat treatment at 1000°C under N2 atmosphere for 45–120min. In addition, heating time has a remarkable effect on N content and type in N-MLG. The resulting N-MLG exhibited higher catalytic activity than undoped graphene and carbon nanotubes (CNTs), as well as comparable catalytic activity to commercial Pt/C catalyst toward oxygen reduction reaction (ORR). Furthermore, the catalytic activity was sensitive to N content and type, particularly the ratio of pyridinic-N to total N atoms. Results showed that Fe atoms in N-MLG were found to function not as synergetic catalysts for ORR but as catalytic growth agents for N-MLG formation, thereby promoting and stabilizing N atoms. The present method could lead to the synthesis of bulk amounts of N-MLG, which is promising for applications in electrochemical energy devices, such as fuel cells and metal–air batteries. [Copyright &y& Elsevier]

Highlights: [•] LiNi0.5Sm x Mn1.5−x O4 (x =0, 0.01, 0.03, and 0.05) spinel have been synthesized. [•] The Sm-doping improves the spinel structural stability. [•] LiNi0.5Sm x Mn1.5−x O4 exhibit enhanced cycling stability and rate performance. [•] LiNi0.5Sm x Mn1.5−x O4 display low charge transfer impedance. [ABSTRACT FROM AUTHOR]

Highlights: [•] Ni–Al co-doped ZnO (NiAl:ZnO) composite thin films were deposited by DC magnetron sputtering at room temperature. [•] All films showed a highly preferential (002) c-axis orientation. [•] XPS revealed the presence of metallic Ni, NiO, and Ni2O3 states, and Ni atoms were successfully doped in the NiAl:ZnO films. [•] NiAl:ZnO (3wt% Ni) film showed the lowest electrical resistivity of 2.59×10−3 Ωcm. [•] Band gap widening (4.18eV) was observed in the NiAl:ZnO films with 5wt% Ni. [ABSTRACT FROM AUTHOR]

Highlights: [•] Template-free synthesis of ZnSe and ZnSe:La nanoparticles was developed at low temperature 100°C. [•] Cubic ZnSe and ZnSe:La nanoparticles were obtained by chemical route. [•] As-synthesized ZnSe:La nanoparticles showed higher emission intensity than ZnSe nanoparticles. [•] Band gap (E g) of ZnSe nanoparticles was bigger than ZnSe nanoparticles due to nanosized effect. [ABSTRACT FROM AUTHOR]