Band Gap Engineering and Trap Depths of Intrinsic Point Defects in RAlO (R = Y, La, Gd, Yb, Lu) Perovskites.

The possibility of band gap engineering (BGE) in RAlO (R = Y, La, Gd, Yb, Lu) perovskites in the context of trap depths of intrinsic point defects was investigated comprehensively using experimental and theoretical approaches. The optical band gap of the materials, , was determined via both the absorption measurements in the VUV spectral range and the spectra of recombination luminescence excitation by synchrotron radiation. The experimentally observed effect of reduction from ∼8.

Rietveld refinement of the langbeinite-type phosphate KNiHf(PO).

Polycrystalline potassium nickel(II) hafnium(IV) tris-(orthophosphate), a langbeinite-type phosphate, was synthesized by a solid-state method. The three-dimensional framework of the title compound is built up from two types of [O] octa-hedra [the sites are occupied by Hf:Ni in ratios of 0.754 (8):0.

NaNiPO-Ni(OH) core-shell nanoparticles as hybrid electrocatalysts for the oxygen evolution reaction in alkaline electrolytes.

There is wide interest in developing efficient, robust and low-cost electrode materials for the electrolysis of water to produce clean hydrogen fuel. It is especially important to improve the performance and durability of electrocatalysts for the OER. Here we have shown that the transformation of nanoparticle (n-NNP) and crystalline (c-NNP) forms of mixed phosphate Na4Ni3(PO4)2P2O7 in highly alkaline solutions occurs along various routes and provokes the generation of 2D Ni(OH)2 nanosheets or stable core(phosphate)-shell(Ni(OH)2) particles, respectively.

Partial Substitution of Potassium with Sodium in the KTi(PO) Langbeinite-Type Framework: Synthesis and Crystalline Structure of KNaTi(PO).

The interaction of TiN with NaO-KO-PO melts was investigated at (Na+K)/P molar ratios of 0.9, 1.0, and 1.

Experimental and theoretical studies of nonlinear dependence of the internal resistance and electrode thickness for high performance supercapacitor.

In this study, the internal resistance with the increasing of electrode thickness in a typical nanoporous carbon-based supercapacitor and their corresponding electrochemical performances were designed and investigated in detail. As for the carbon-based double electrode layer electrochemical system, electrochemical experiments greatly support the fact of nonlinear dependence and indicate that the curve of internal resistance vs. electrode thickness can have a minimum value when the thickness increasing from 10 to 140 μm.

Porous biomorphic silicon carbide ceramics coated with hydroxyapatite as prospective materials for bone implants.

Porous and cytocompatible silicon carbide (SiC) ceramics derived from wood precursors and coated with bioactive hydroxyapatite (HA) and HA-zirconium dioxide (HA/ZrO2) composite are materials with promising application in engineering of bone implants due to their excellent mechanical and structural properties. Biomorphic SiC ceramics have been synthesized from wood (Hornbeam, Sapele, Tilia and Pear) using a forced impregnation method. The SiC ceramics have been coated with bioactive HA and HA/ZrO2 using effective gas detonation deposition approach (GDD).

Structure of Biocompatible Coatings Produced from Hydroxyapatite Nanoparticles by Detonation Spraying.

Detonation-produced hydroxyapatite coatings were studied by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), Raman spectroscopy, and electron paramagnetic resonance (EPR) spectroscopy. The source material for detonation spraying was a B-type carbonated hydroxyapatite powder. The coatings consisted of tetracalcium phosphate and apatite.