RbEu(MoO4)2 is synthesized by the two-step solid state reaction method. The crystal structure of RbEu(MoO4)2 is defined by Rietveld analysis in space group Pbcn with cell parameters a = 5.13502(5), ...b = 18.8581(2) and c = 8.12849(7) Å, V = 787.13(1) Å3, Z = 4 (RB = 0.86%). This molybdate possesses its phase transition at 817 K and melts at 1250 K. The Raman spectra were measured with the excitation at λ = 1064 and 514.5 nm. The photoluminescence spectrum is evaluated under the excitation at 514.5 nm. The absolute domination of hypersensitive 5D0→7F2 transition is observed. The ultranarrow 5D0→7F0 transition in RbEu(MoO4)2 is positioned at 580.2 nm being 0.2 nm blue shifted, with respect to that in Eu2(MoO4)3.
•RbEu(MoO4)2 is synthesized by the two-step solid state reaction method.•The crystal structure of RbEu(MoO4)2 is defined by Rietveld analysis in space group Pbcn.•The absolute domination of hypersensitive 5D0.→7F2 transition is observed.
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•Surface morphology after ns IR and visible laser processing of c-Si is analyzed.•A regular cleavage crack grid is formed by IR irradiation in any surrounding.•Periodic microhillocks ...at the grid nodes are produced by IR processing in air.•The microstructure is formed due to hydrodynamic instability of a Si/SiO2 bilayer.•The produced periodic microstructure leads to Si surface superhydrophilicity.
The evolution of the morphology and composition of the single-crystal silicon surface irradiated by infrared and visible nanosecond laser pulses is investigated as a function of processing parameters (laser fluence, irradiation spot size, the number of pulses, background gas pressure and composition). Two types of periodic surface microstructures are obtained with IR (1064 nm) laser pulses in a narrow fluence range of 3–6 J/cm2. At a relatively low number of laser pulses applied, a grid of cleavage cracks is produced within the irradiation spot along the crystal orientation. With further Si irradiation, periodic microhillocks are formed in the nodes of the crack grid. Silicon surface with such microhillocks exhibits superhydrophilic properties which are retained during prolonged storage in air. The cracks are produced in any environment (including vacuum) but the microhillocks are observed only in the presence of oxygen. No periodic structures were observed with visible (532 nm) laser pulses. Mechanisms of nanosecond laser-induced periodic microstructure formation on silicon are discussed.
•Experimental study of the effect of graphene coatings on the wettability of surfaces, both atomically smooth and textured superhydrophilic and superhydrophobic silicon surfaces with identical ...morphology.•A mechanism is proposed to explain the observed difference in the nature of contact between textured surfaces with superhydrophobic and superhydrophilic properties.•The adhesion density during transfer through water depends on the hydrophilicity of the surface.•Estimates of the forces and surface tension during drying of the liquid between graphene and the substrate have shown that the Laplace pressure can be sufficient to deform the graphene coating.•It has been demonstrated that the transparency of the wettability of graphene coatings can be adjusted using graphene-substrate-liquid systems with different lyophilicity to each other.
The work is dedicated to analyzing the influence of substrate texture and its wettability on the deformation of the graphene layer during transfer through a liquid medium, as well as investigating the transparency effect of graphene wetting on various substrates. The research was conducted on smooth silicon substrates with varying oxide layer thickness and on textured substrates. Experimental evidence demonstrates that the transparency of graphene in terms of wetting changes with variations in the graphene-substrate contact density. Assessments were made regarding the forces that deform the graphene coating during the drying of the liquid trapped between the graphene and the substrate, revealing that Laplace's pressure can determine the degree of graphene adhesion to the substrate.
The first fully inorganic Pt(IV) carbonato-complex trans-Pt(CO3)2(OH)22- with a {PtO6} coordination sphere was isolated as the (Me4N)2Pt(CO3)2(OH)2 (1) salt. The compound 1 was characterized using ...single-crystal and powder X-ray diffraction, Raman spectroscopy, infrared spectroscopy (FTIR), electrospray ionization mass spectrometry (ESI-MS), nuclear magnetic resonance spectroscopy (NMR), and thermogravimetric analysis (TG). Density functional theory (DFT) calculations were also performed to analyze the spectral features of the complex. 1 crystallizes in the triclinic system (P-1) with a Z of 1. The trans-Pt(CO3)2(OH)22- anion has axial hydroxo ligands and κ2-CO3 ligands, which form an equatorial plane. This anionic complex exhibits notable stability in aqueous solutions, while the axial hydroxo ligand can be readily modified, as exemplified by the acylation of the trans-Pt(CO3)2(OH)22- into trans-Pt(CO3)2(OAc)22- anion. Furthermore, it has been shown that rigid and glittering platinum coatings can be electrochemically deposited from an aqueous solution of 1 without the addition of surfactants.The first fully inorganic Pt(IV) carbonato-complex trans-Pt(CO3)2(OH)22- with a {PtO6} coordination sphere was isolated as the (Me4N)2Pt(CO3)2(OH)2 (1) salt. The compound 1 was characterized using single-crystal and powder X-ray diffraction, Raman spectroscopy, infrared spectroscopy (FTIR), electrospray ionization mass spectrometry (ESI-MS), nuclear magnetic resonance spectroscopy (NMR), and thermogravimetric analysis (TG). Density functional theory (DFT) calculations were also performed to analyze the spectral features of the complex. 1 crystallizes in the triclinic system (P-1) with a Z of 1. The trans-Pt(CO3)2(OH)22- anion has axial hydroxo ligands and κ2-CO3 ligands, which form an equatorial plane. This anionic complex exhibits notable stability in aqueous solutions, while the axial hydroxo ligand can be readily modified, as exemplified by the acylation of the trans-Pt(CO3)2(OH)22- into trans-Pt(CO3)2(OAc)22- anion. Furthermore, it has been shown that rigid and glittering platinum coatings can be electrochemically deposited from an aqueous solution of 1 without the addition of surfactants.
The first fully inorganic Pt(IV) carbonato-complex trans-Pt(CO3)2(OH)22– with a {PtO6} coordination sphere was isolated as the (Me4N)2Pt(CO3)2(OH)2 (1) salt. The compound 1 was characterized using ...single-crystal and powder X-ray diffraction, Raman spectroscopy, infrared spectroscopy (FTIR), electrospray ionization mass spectrometry (ESI-MS), nuclear magnetic resonance spectroscopy (NMR), and thermogravimetric analysis (TG). Density functional theory (DFT) calculations were also performed to analyze the spectral features of the complex. 1 crystallizes in the triclinic system (P-1) with a Z of 1. The trans-Pt(CO3)2(OH)22– anion has axial hydroxo ligands and κ2-CO3 ligands, which form an equatorial plane. This anionic complex exhibits notable stability in aqueous solutions, while the axial hydroxo ligand can be readily modified, as exemplified by the acylation of the trans-Pt(CO3)2(OH)22– into trans-Pt(CO3)2(OAc)22– anion. Furthermore, it has been shown that rigid and glittering platinum coatings can be electrochemically deposited from an aqueous solution of 1 without the addition of surfactants.
The systematic study of the platinum speciation in sulfuric acid solutions of platinum (IV) hydroxide {Pt(OH)4(H2O)2, HHPA} was performed with the use of a combination of methods. Depending on the ...prevailing Pt form, the three regions of H2SO4 concentration were marked: (1) up to 3 M H2SO4 forms unstable solutions gradually generating the PtO2·xH2O particles; (2) 4–12 M H2SO4, where the series of mononuclear aqua–sulfato complexes (Pt(SO4) n (H2O)6–n 4–2n , where n = 0···4) dominate; and (3) 12 M and above, where, along with Pt(SO4) n (H2O)6–n 4–2n species, the polynuclear Pt(IV) species and complexes with a bidentate coordination mode of the sulfato ligand are formed. For the first time, the salts of the aqua–hydroxo Pt(IV) cation Pt(OH)2(H2O)4SO4 (triclinic and monoclinic phases) were isolated and studied with a combination of methods, including the single-crystal X-ray diffraction. The formation of PtO2·xH2O particles in sulfuric acid solutions (1–3 M) of HHPA and their spectral characteristics and morphology were studied. The deposition of PtO2·xH2O was highlighted as a convenient method to prepare various Pt-containing heterogeneous catalysts. This possibility was illustrated by the preparation of Pt/g-C3N4 catalysts, which show an excellent performance in catalytic H2 generation under visible light irradiation with a quantum efficiency up to 5% and a rate of H2 evolution up to 6.2 mol·h–1 per gram of loaded platinum.
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