Novel Bifunctional VO Nanosheets Coupled with N-Doped-Carbon Encapsulated Ni Heterostructure for Enhanced Electrocatalytic Oxidation of Urea-Rich Wastewater.

Developing high performance bifunctional transition metal catalysts would be significantly beneficial for electrocatalytic oxidation of urea-rich wastewater. Herein, we synthesize a VO nanosheet anchored N-doped-carbon encapsulated Ni heterostructure (Ni@C-VO/NF) for the reactions of urea oxidation (UOR) and hydrogen evolution (HER). Electrochemical results indicate that it exhibits small potentials of 1.

Photocatalytic Properties of BiTiO ( = 0, 0.5) Pyrochlores: Hybrid DFT Calculations and Experimental Study.

The photocatalytic properties of BiTiO ( = 0, 0.5) pyrochlores are examined via calculations and experiments. A coprecipitation method is applied for the synthesis of nanopowder pyrochlores.

Identification and first insights into the structure of chitin from the endemic freshwater demosponge Ochridaspongia rotunda (Arndt, 1937).

Studies on the identification, properties and function of chitin in sponges (Porifera), which are recognized as the first multicellular organisms on Earth, continue to be of fundamental scientific interest. The occurrence of chitin has so far been reported in 21 marine sponge species and only in two inhabiting fresh water. In this study, we present the discovery of α-chitin in the endemic demosponge Ochridaspongia rotunda, found in Lake Ohrid, which dates from the Tertiary.

Computer Test of a Modified Silicene/Graphite Anode for Lithium-Ion Batteries.

Despite the considerable efforts made to use silicon anodes and composites based on them in lithium-ion batteries, it is still not possible to overcome the difficulties associated with low conductivity, a decrease in the bulk energy density, and side reactions. In the present work, a new design of an electrochemical cell, whose anode is made in the form of silicene on a graphite substrate, is presented. The whole system was subjected to transmutation neutron doping.

Electrochemical Approach for Isolation of Chitin from the Skeleton of the Black Coral sp. (Antipatharia).

The development of novel and effective methods for the isolation of chitin, which remains one of the fundamental aminopolysaccharides within skeletal structures of diverse marine invertebrates, is still relevant. In contrast to numerous studies on chitin extraction from crustaceans, mollusks and sponges, there are only a few reports concerning its isolation from corals, and especially black corals (Antipatharia). In this work, we report the stepwise isolation and identification of chitin from sp.

Oxygen surface exchange kinetics of BaSrCoFeO.

The mechanism of oxygen exchange between the gas phase and BaSrCoFeO oxide was evaluated by considering the inhomogeneity of the oxide surface. The applicability of existing models for the analysis of the oxygen exchange mechanism was considered. A new model with a dissociation step was suggested.

3D Chitin Scaffolds of Marine Demosponge Origin for Biomimetic Mollusk Hemolymph-Associated Biomineralization .

Structure-based tissue engineering requires large-scale 3D cell/tissue manufacture technologies, to produce biologically active scaffolds. Special attention is currently paid to naturally pre-designed scaffolds found in skeletons of marine sponges, which represent a renewable resource of biomaterials. Here, an innovative approach to the production of mineralized scaffolds of natural origin is proposed.

Surface-Dependent Osteoblasts Response to TiO Nanotubes of Different Crystallinity.

One of the major challenges of implantology is to design nanoscale modifications of titanium implant surfaces inducing osseointegration. The aim of this study was to investigate the behavior of rat osteoblasts cultured on anodized TiO nanotubes of different crystallinity (amorphous and anatase phase) up to 24 days. TiO nanotubes were fabricated on VT1-0 titanium foil via a two-step anodization at 20 V using NHF as an electrolyte.

Theoretical modeling of electrochemical nucleation and growth of a single metal nanocluster on a nanoelectrode.

Theory of the initial stages of electrochemical formation and growth of a single metal nanocluster on an indifferent nanoelectrode has been developed and analyzed. General theoretical time dependences of the current and nanocluster size have been presented for the case of diffusion controlled growth at potentio- and galvanostatic deposition, and cyclic voltammetry.

Synthesis, spectroscopic and luminescence properties of Ga-doped γ-AlO.

Gallium-doped aluminum oxide (AlGa)O with γ-AlO (spinel) structure has been synthesized by the precursor method using the formate AlGa(OH)(HCOO) as a precursor. The examination of AlGa(OH)(HCOO) (x = 0.0, 0.

Oxygen surface exchange and diffusion in mayenite single crystal.

Oxygen surface exchange and diffusion in CaAlO single crystal were studied by a unique in situ method based on isotope equilibration in the gas phase. Although the interphase exchange rate and oxygen diffusion coefficient demonstrate good agreement with available data, only the employed method is efficient to isolate the contributions of various types of exchange; thus, for the first time, it is possible to estimate the surface heterogeneity of mayenite. The obtained results disprove conclusions previously developed in the literature; the temperature region of 750 °C to 850 °C is not the intermediate region where two types of oxygen diffusion coexist.

Band gap engineering and transport properties of BaInO: effect of fluorine doping and hydration.

Two types of fluorine doped barium indate solid solutions were prepared by a solid state method: BaInOF (x = 0, 0.1, 0.2) and BaInOF (y = 0, 0.

Thermoelectric Behavior of BaZrYO Proton Conducting Electrolyte.

BaZrYO (BZY10), a promising proton conducting material, exhibits p-type conduction under oxidative conditions. Holes in BZY10 are of the small polaron type. However, there is no clear understanding at which places in the lattice they are localized.

Comparative Study of Electrophoretic Deposition of Doped BaCeO-Based Films on LaNiO and LaBaNiO Cathode Substrates.

This paper presents the results of a comparative study of methods to prevent the loss of barium during the formation of thin-film proton-conducting electrolyte BaCeGdCuO (BCGCuO) on LaNiO-based (LNO) cathode substrates by electrophoretic deposition (EPD). Three different methods of the BCGCuO film coating were considered: the formation of the BCGCuO electrolyte film without (1) and with a protective BaCeO (BCO) film (2) on the LNO electrode substrate and the formation of the BCGCuO electrolyte film on a modified LaBaNiO (LBNO) cathode substrate (3). After the cyclic EPD in six stages, the resulting BCGCuO film (6 μm) (1) on the LNO substrate was completely dense, but the scanning electron microscope (SEM) analysis revealed the absence of barium in the film caused by its intensive diffusion into the substrate and evaporation during the sintering.

The Adhesion of Human Dermal Fibroblasts on Anodized Nanotube-layered Titanium, Modified for Implantology Application.

Anodization of titanium implants is accompanied by the formation of titanium oxide nanotubes improving osseointegration. An excessive fibroblast adhesion on the surface might lead to the formation of fibrous capsule resulting in implant rejection. In our research, we demonstrated that the adhesion activity of human dermal fibroblasts on anodized surface was not elevated, which is promising for the use of titanium with nanotube-layered surface for implantology.

Water Uptake and Transport Properties of LaCaScO Proton-Conducting Oxides.

In this study, oxide materials LaCaScO (x = 0.03, 0.05 and 0.

Computational investigation of a promising Si-Cu anode material.

The lack of suitable anode materials is a limiting factor in the creation of a new generation of lithium-ion batteries. We use the molecular dynamics method to explore the processes of intercalation and deintercalation of lithium in the anode element, represented by two sheets of silicene, on a copper substrate. It is shown that the presence of vacancy-type defects in silicene increases the electrode capacitance, which becomes especially significant with bivacancies.

Effect of A-Site Nonstoichiometry on Defect Chemistry and Electrical Conductivity of Undoped and Y-Doped SrZrO.

The effect of Sr-nonstoichiometry on phase composition, microstructure, defect chemistry and electrical conductivity of SrZrO and SrZrYO ceramics (SZx and SZYx, respectively; x = 0.94-1.02) was investigated via X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy and impedance spectroscopy followed by distribution of relaxation times analysis of impedance data.

Effect of proton uptake on the structure of energy levels in the band-gap of Sr-doped LaScO: diffuse reflectance spectroscopy and coherent potential approximation calculations.

Features of the energy levels in the band-gap of LaSrScO and the effect on those levels of proton uptake from H and HO atmospheres were studied by diffuse reflectance spectroscopy and coherent potential approximation (CPA) calculations. It was shown that oxygen vacancies appearing due to acceptor doping with Sr form energy levels near the bottom of the conduction band that are strongly hybridized with the states of the nearest atoms. Excitation of electrons from the valence band to these vacancy levels gives rise to an additional absorption band which overlaps with the fundamental absorption edge.

Impact of bound ionic defects on the hydration of acceptor-doped proton-conducting perovskites.

The role of various acceptor-bound states of ionic defects in the defect thermodynamics and hydration of acceptor-doped proton-conducting perovskites is theoretically studied. It is shown that the relation between the trapping energies of protons (ΔE) and vacancies (ΔE) bound to acceptor impurities is one of the major factors governing hydration. As the trapping energies ΔE and ΔE increase, the proton concentration at not too low temperatures can either increase or decrease depending on the ΔE/ΔE ratio.

Oxygen surface exchange and diffusion in PrSrNiCoO.

Oxygen surface exchange and diffusion in Pr1.75Sr0.25Ni0.

A Reversible Protonic Ceramic Cell with Symmetrically Designed Pr₂NiO-Based Electrodes: Fabrication and Electrochemical Features.

Reversible protonic ceramic cells (rPCCs) combine two different operation regimes, fuel cell and electrolysis cell modes, which allow reversible chemical-to-electrical energy conversion at reduced temperatures with high efficiency and performance. Here we present novel technological and materials science approaches, enabling a rPCC with symmetrical functional electrodes to be prepared using a single sintering step. The response of the cell fabricated on the basis of P⁻N⁻BCZD|BCZD|PBN⁻BCZD (where BCZD = BaCeZrDyO, PBN = PrBaNiO, P = Pr₂O₃, N = Ni) is studied at different temperatures and water vapor partial pressures (pH₂O) by means of volt-ampere measurements, electrochemical impedance spectroscopy and distribution of relaxation times analyses.

Designing a protonic ceramic fuel cell with novel electrochemically active oxygen electrodes based on doped NdBaFeO.

The Fe-based perovskite-structured Nd0.5Ba0.5FeO3-δ (NBF) system represents the basis for developing promising electrode materials for solid oxide fuel cells with proton-conducting electrolytes.

Phase Composition, Density, and Ionic Conductivity of the LiLaZrO-Based Composites with LiPO Glass Addition.

The glass-ceramic composite electrolytes based on tetragonal LiLaZrO (t-LLZ) and cubic Al-doped LiLaZrO (c-LLZ) with the LiPO glass additive have been prepared. The electrical conductivity and microstructure of the t-LLZ/LiPO and c-LLZ/LiPO composites have been investigated. The phase evolution of electrolytes has been studied using XRD, SEM, and Raman spectroscopy.