Synthesis, Crystal Structure and Characterization of the Barium Zinc Tellurate Disilicate: Ba3Zn6[TeO6][Si2O7]2

Ba3SnGa10-xInxO20 (0 ≤ x ≤ 2): site-selective doping, band structure engineering and photocatalytic overall water splitting

Developing new photocatalysts and deciphering the structure-property relationship are always the central topics in photocatalysis. In this study, a new photocatalyst Ba3SnGa10O20 containing two d10 metal cations was prepared by a high temperature solid state reaction, and its crystal structure was investigated by Rietveld refinements of monochromatic X-ray powder diffraction data for the first time. There are 2 Ba, 4 metal cations and 6 O independent atoms in a unit cell. Sn4+ and Ga3+ co-occupy the octahedral cavities named M1 and M2 sites, and the other two metal sites are fully occupied by Ga3+. Rational In3+-to-Ga3+ substitution was performed to reduce the potential of the conduction band minimum and enhance the light absorption ability, which was indeed confirmed using UV-vis diffuse reflectance spectra and Mott-Schottky plots for Ba3SnGa10-xInxO20 (0 ≤ x ≤ 2). Interestingly, In3+ exhibits site selective doping at M1 and M2 sites exclusively. With the light absorption ability enhanced, the photocatalytic overall water splitting activity was also improved, i.e. the photocatalytic H2 generation rate was 1.7(1) μmol h-1 for Ba3SnGa10O20, and the optimal catalyst Ba3SnGa8.5In1.5O20 loaded with 1.0 wt% Pd exhibited the H2 generation rate of 27.5(4) μmol h-1 and the apparent quantum yield at 254 nm was estimated to be 2.28% in pure water.

Process Oxygen Flow Influence on the Structural Properties of Thin Films Obtained by Co-Sputtering of (TeO2)x-ZnO and Au onto Si Substrates

In this study, we investigated the structural properties of TeO2-ZnO (TZ) and TeO2-ZnO-Au (TZA) thin films sputtered under different oxygen concentrations and either annealed or not annealed at 325 °C in air for 10 or 20 h. The lattice changes of the tellurium oxide were shown to be inherent in the polymorph properties of the α and β phases. The β phase was formed for null oxygen flow and the α phase was formed for different oxygen flows (0.5-7.0 sccm) during TZ and TZA sputtering. Au was encountered in its single phase or as AuTe2. The annealing had very little influence on the α and β phases for both TZ and TZA. It is worth noting that SiO2 and orthotellurate anions are both formed for not-null oxygen flow. An electrochemical mechanism was proposed to explain the SiO2 growth at the TZ/Si or TZA/Si interface, taking the orthotellurate anion as oxidizing agent into account.

BaGa4O7, a new A3BC10O20 crystalline phase: synthesis, structural determination and luminescence properties

A new compound, BaGa₄O₇, is found by cooling from the melt. Part of the A₃BC₁₀O₂₀ family, it exhibits strong orange-red luminescence emission when doped with Eu³⁺.

Synthesis, structures, and properties of two magnesium silicate fluorides Mg5(SiO4)2F2 and Mg3SiO4F2

The structural differences of title compounds were investigated, and the related physical properties and theoretical calculations were also reported.

Bi2Te(IO3)O5Cl: a novel polar iodate oxychloride exhibiting a second-order nonlinear optical response

A novel iodate oxychloride Bi₂Te(IO₃)O₅Cl with a second-order nonlinear optical response originating from constructive stacking of dipole moments of IO₃.