Interplay between A-site and oxygen-vacancy ordering, and mixed electron/oxide-ion conductivity in = 1 Ruddlesden-Popper perovskite SrNdZnO.

Oxygen vacancies in Ruddlesden-Popper (RP) perovskites (PV) [AO][ABO] play a pivotal role in engineering functional properties and thus understanding the relationship between oxygen-vacancy distribution and physical properties can open up new strategies for fine manipulation of structure-driven functionalities. However, the structural origin of preferential distribution for oxygen vacancies in RP structures is not well understood, notably in the single-layer ( = 1) RP-structure. Herein, the = 1 RP phase SrNdZnO was rationally designed and structurally characterized by combining three-dimensional (3D) electron diffraction and neutron powder diffraction.

BaSnGaInO (0 ≤ ≤ 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 BaSnGaO containing two d 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.

From Lewis Acid to Lewis Base by La-to-Y Substitution in α-YBO: Local Structure Modification Induced Lewis Basicity.

Different from the common perspective of average structure, we propose that the locally elongated metal-oxygen bonds induced by La-to-Y substitution to a Lewis acid α-YBO generate medium-strength basic sites. Experimentally, NH- and CO-TPD experiments prove that the La doping of α-YLaBO (0 ≤ ≤ 0.24) results in the emergence of new medium-strength basic sites and the increasing La concentration modifies the number, not the strength, of the acidic and basic sites.

Combined Analyses on Electronic Structure and Molecular Orbitals of d Bimetal Oxide InGeO and Photocatalytic Performances for Overall Water Splitting and CO Reduction.

Semiconducting photocatalytic overall water splitting and CO reduction are possible solutions to the emerging worldwide challenges of oil shortage and continual temperature increase, and the key is to develop an efficient photocatalyst. Most photocatalysts contain the d, d or dns metals, and a guiding principle is desired to help to distinguish outstanding semiconductors. Here, the d bimetal oxide InGeO was selected as the target.

First-Principles Calculations on Narrow-Band Gap d Metal Oxides for Photocatalytic H Production: Role of Unusual In Cations in Band Engineering.

The d metal oxides with low effective mass and high mobility of photoexcited electrons have received much attention in photocatalytic water splitting. However, there are still challenges in practical application due to insufficient visible light absorption. Here, an unusual phenomenon of the In cation in PtIn(GeO)O and PtIn(Ga/InO) with a narrow band gap is systematically investigated using density functional theory calculations.

Deciphering the photocatalytic hydrogen generation process of Fresnoite BaTiGeO by electronic structure and bond analyses.

In addition to enhancing the activity of already-known photocatalysts, developing new ones is always desired in photocatalysis, giving more opportunities to approach practical applications. Most photocatalysts are composed of d ( Sc, Ti, Zr) and/or d ( Zn, Ga, In) metal cations, and a new target catalyst is BaTiGeO containing both. Experimentally, it exhibits a UV-driven catalytic H generation rate of 0.

Temperature-driven order-disorder structural transition in the oxygen sub-lattice and the complex superstructure of the high-temperature polymorph of CaSrZnGaO.

Structural order-disorder plays a decisive role in the physical properties of materials, such as magnetism, second-order harmonic generation, and ionic conductivity, and it is thus widely utilized to manipulate the crystal structure and understand structure-property correlations. Herein, we report the structural polymorphism, complex crystal structure and temperature-driven irreversible order-disorder phase transition of the polar oxides (SrCa)SrZnGaO. The low-temperature (LT) structure crystallizes in 2 with partial Zn/Ga ordering.