Structural, Mössbauer and magnetic study of (Mn0.2Co0.2Ni0.2Cu0.2X0.2) Fe2O4 (X=Fe, Mg) spinel high-entropy oxides fabricated via reactive flash sintering

Herein, it is reported the concomitant synthesis and sintering in a single step of (Mn0.2Co0.2Ni0.2Cu0.2X0.2)Fe2O4 (X=Fe, Mg), a spinel-structured high-entropy oxides, by the reactive flash sintering technique. A single phase, identified with a spinel crystal structure Fd3m, was obtained in just 30 min at a furnace temperature of 1173 K. The structural and magnetic properties…

Influence of vanadium species on the catalytic oxidation of glucose for formic acid production

VOx/TiO2 catalysts with various theorical monolayer values have been prepared and used to study, for the first time, the effect of vanadium loading in the selective oxidation of glucose to formic acid. Monomeric or isolated vanadia species dominate at low loadings, evolving into polymeric chains at higher concentrations, while crystalline V2O5 is observed at loadings over the…

Zn2-xGeO4-GeO2:(x)Mn2+ films with long persistence, intense brightness and high quantum efficiency, deposited by ultrasonic spray pyrolysis

This work shows the synthesis and characterization of the Zn2-xGeO4-GeO2:(x)Mn2+ (x = 0.10, 0.25, and 0.50 at.%) films using the Ultrasonic Spray Pyrolysis (USP) technique. These films were deposited at 500 degrees C and heat treated at 800 degrees C for 13 h. X-ray diffraction (XRD) measurements showed the rhombohedral and hexagonal phases of Zn2-xGeO4…

Influence of the atmosphere on the formation of high-entropy oxides within the Co–Cu–Fe–Mg–Mn–Ni–O system via reactive flash sintering

In this study, the feasibility of preparing quinary equimolar high-entropy oxides within the Co–Cu–Fe–Mg–Mn–Ni–O system was explored using the reactive flash sintering (RFS) technique. Various compositions were tested using this technique under atmosphere pressure, leading to the formation of two primary phases: rock-salt and spinel. Conversely, a new high-entropy oxide was produced as a single-phase…

Intense and Stable Blue Light Emission From CsPbBr3/Cs4PbBr6 Heterostructures Embedded in Transparent Nanoporous Films

Lead halide perovskite nanocrystals are attractive for light emitting devices both as electroluminescent and color-converting materials since they combine intense and narrow emissions with good charge injection and transport properties. However, while most perovskite nanocrystals shine at green and red wavelengths, the observation of intense and stable blue emission still remains a challenging target. In…

P-functionalization of Ni Fe − Electrocatalysts from Prussian blue analogue for enhanced anode in anion exchange membrane water electrolysers

Efficient hydrogen generation from water-splitting is widely acknowledged as a priority route to promote the hydrogen economy. Anion exchange membrane water electrolyzers (AEMWE) offer multiple advantages in improving performance and minimizing the cost limitations of current electrolysis technologies. However, the persistence of issues related to the limited electrocatalytic activity of such materials and their poor…