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In this study we investigate the effect of the nanoporous anodic titanium oxide substrate on the morphology and uniformity of hydrothermally precipitated hydroxyapatite coatings. Nanotubular TiO 2 substrates were synthesized on a titanium plate by anodic oxidation and subsequently annealed at 500 °C or 600 °C to create the crystalline anatase and/or rutile forms of TiO 2 . The substrates were further used for HAp growth under hydrothermal conditions. The samples were then characterized with the XRD, Raman and SEM techniques. The results show that hydrothermal synthesis leads to formation of needle-like coating layer of HAp particles. The diameter and length of HAp crystals decrease with increasing annealing temperature of TiO 2 nanotubular arrays. Furthermore, we demonstrate that nanostructured surface of titanium oxide has beneficial influence on the HAp nucleation and coverage. [ABSTRACT FROM AUTHOR]

A new X-ray absorption spectroscopy (XAS) beamline is currently under construction at a bending magnet of the National Synchrotron Radiation Centre SOLARIS. The front end of this beamline was installed in April 2020. This beamline has a few outstanding characteristic features: The monochromator is a fixed exit beam Lemmonier type monochromator allowing to cover the pursued energy range (1 keV to ~15 keV) with 3 sets of crystals: KAP (100) + multilayer, InSb (111) and Ge (220). The monochromator is a high vacuum system allowing the change of crystals in less than an hour. In order to minimize absorption of photons no windows will be installed in the beamline down to the monochromator, and just one thin polypropylene window will be used for separating the vacuum of the monochromator from the ionization chambers and the sample chamber. A special differential ion pump will be installed to maintain the pressure difference of four orders of magnitude between the storage ring and the monochromator. As SOLARIS is a low energy machine, the beamline can be built without any radiation safety hutches without exceeding the strict low radiation safety levels. The straightforward design of the beamline without additional optical elements, its compact overall dimensions and an easy to handle monochromator make this beamline especially user friendly. In combination with the characteristics of the 1.5 GeV SOLARIS storage ring this beamline will be specifically attractive for the tender X-ray range, i.e. the K-edges of important elements such as P, S, Si, Al and Mg. [ABSTRACT FROM AUTHOR]

[Display omitted] • Atomically dispersed Cu on TiO2 nanoparticles synthesized by the wet impregnation method; • 100% Selectivity to hydrogen in the methanol photoreforming has been achieved; • Cu2+ Oxidation state bypassed to prevent CO 2 generation; • Cu+→Cu0 → Cu+ Redox cycle identified under the reaction conditions; • An apparent quantum efficiency of 10% at λ = 365 nm and the 0.45 W LED source. Hydrogen generation by photoreforming of methanol is being one of the most intensely investigated photochemical transformations in pursuing a sustainable, zero waste circular economy. This transformation usually produces a significant amount of gaseous carbon in the form of CO 2 and CO that disqualifies many active photocatalysts as being fully sustainable. Here, we demonstrate the atomically dispersed Cu on TiO 2 composite nanoparticles synthesized by the wet impregnation method that are highly active and selective in hydrogen production by photoreforming of methanol solution. Our photocatalyst exhibits an apparent quantum efficiency of 10% at 365 nm wavelength and the low power 0.45 W light emitting diode (LED) source. The only gaseous product found is molecular hydrogen, whereas all carbon is trapped in the downstream liquid mixture of formaldehyde and formic acid, making the process fully sustainable and clean. We used various experimental techniques and density functional theory calculations (DFT) to characterize our photocatalysts and provide an insight into the exceptional behavior of the Cu/TiO 2 system. A combination of ab initio DFT and X–ray photoelectron spectroscopy (XPS) measurements allowed us to identify the Cu+–Cu0–Cu+ redox cycle under the reaction conditions. Bypassing the Cu2+ oxidation state is crucial to keep the oxidation potential of photogenerated holes low enough to prevent CO 2 generation and keeping all carbon in the liquid phase. This work paves the way toward an efficient and clean generation of hydrogen by photoreforming of methanol over well–established and cheap Cu/TiO 2 photocatalyst. [ABSTRACT FROM AUTHOR]

We studied the magnetic properties of Co nanowires electrodeposited in polycarbonate membranes as a function of the electrodeposition and template parameters. We showed the response of the current as a function of time, for nanowires prepared in various conditions. X-ray diffraction measurements indicate that nanowires have polycrystalline hcp structure with small addition of fcc phase. Magnetic properties analyzed by SQUID measurements suggest that easy axis of magnetization follows the nanowire axis with coercivity increasing with a decrease of nanowire diameter and length. The largest coercivity, equal to 850 Oe, was obtained for nanowires with the diameter of 30 nm and the length of 1.5 μm. We find the coercivity to be insensitive to pH value. Low electrodeposition temperature, low cathodic potential, and medium pH are the synthesis parameters most beneficial for large coercivity and/or magnetic anisotropy with easy axis along nanowires. [ABSTRACT FROM AUTHOR]