Chemical Design of a New Displacive-type Ferroelectric

Since the discovery of the ferroelectric perovskite-type oxide BaTiO3 in 1943, numerous materials have been surveyed as candidates for new ferroelectrics. Perovskite-type materials have played a leading role in basic...

Perovskite-Type Oxide-Based Dual Composite Cathode for Solid Oxide Fuel Cells: A Short Review

A fuel cell is an electrochemical device that provides efficient power generation. Solid fuel oxide cell (SOFC) is an electrochemical device that generates electrical energy and heat from the gaseous state of fuel using an oxidant. SOFC is a highly efficient and environmentally friendly power generation technology that generates electrical energy from hydrogen gas, natural gas and other renewable fuel. The implementation of SOFCs is still facing challenges because their performance needs to be improved. Constructing cells with solid material alone is difficult because good electrical contacts between the components must be maintained. The concept of a dual composite cathode is important for the development of SOFC single cells. Introducing dual composite cathode can create an ideal cathode microstructure that can improve phase contiguity and interfacial coherence. This paper reviews the behaviour of a perovskite-type oxide-based dual composite cathode of SOFC for the selection of suitable materials and the preparation of a dual composite cathode.

Oxygen Evolution Activity of LaNbN2O-Based Photocatalysts Obtained from Nitridation of a Precursor Oxide Structurally Modified by Incorporating Volatile Elements

The perovskite-type oxynitride LaNbN2O is a photocatalyst that can evolve oxygen from aqueous solutions in response to long-wavelength visible light. However, it is challenging to obtain active LaNbN2O because of the facile reduction of Nb5+ during the nitridation of the precursor materials. The present study attempted to synthesize a perovskite-type oxide La0.6Na0.4Zn0.4Nb0.6O3, containing equimolar amounts of La3+ and Nb5+ in addition to volatile Na+ and Zn2+, followed by the nitridation of this oxide to generate LaNbN2O. The obtained oxide was not the intended single-phase material but rather comprised a cuboid perovskite-type oxide similar to La0.5Na0.5Zn0.33Nb0.67O3 along with spherical LaNbO4 particles and other impurities. A brief nitridation was found to form a LaNbN2O-like shell structure having a light absorption onset of approximately 700 nm on the cuboid perovskite-type oxide particles. This LaNbN2O-based photocatalyst, when loaded with a CoOx cocatalyst, exhibited an apparent quantum yield of 1.7% at 420 nm during oxygen evolution reaction from an aqueous AgNO3 solution. This was more than double the values obtained from the nitridation products of LaNbO4 and LaKNaNbO5. The present work demonstrates a new approach to the design of precursor oxides that yield highly active LaNbN2O and suggests opportunities for developing efficient Nb-based perovskite oxynitride photocatalysts.

Electric Field Induced Reversal of Spin Polarization, Magnetic Anisotropy and Tailored Dzyaloshinskii-Moriya Interaction in Underoxidized SrRuO3/SrTiO3 Heterostructures

Electric field tailored magnetic properties of perovskite-type oxide heterostructures are important in spintronics devices with low energy consumption and small size. Here, the electric field modulated magnetic properties of underoxidized...