Morphology Control of Transition Metal Oxides by Liquid-Phase Process and Their Material Development

Abstract

It is well known that the functionality of inorganic materials strongly depends on the chemical composition, morphology, particle size, crystal facet, etc., which are strongly influenced by the synthesis process. The precise control of the synthesis process is expected to lead to the discovery of new functionality and improvement of the functionality of materials. For example, in a high-temperature solid-phase reaction, it is difficult to control the morphology of nanocrystals. On the other hand, synthesizing functional materials using solution processes, such as hydrothermal and solvothermal reactions, makes it possible to control the morphology and particle size precisely. Usually, the solution process is strongly related to the dissolution reprecipitation mechanism. Therefore, the material composition can be strictly controlled and is suitable for forming fine particles with high crystallinity. In this review paper, the role of the solvent in the solution process, its effect on particle size and morphology of the transition metal oxide, and the related functional improvement will be focused. Furthermore, the direct formation of functional thin films by the solution process and the morphology control by non-oxide materials by the topotactic reaction will also be introduced.

Nature-inspired compositional control of transition-metal-doped ammoniotinsleyite and spheniscidite particles for design of color hue

“…The particle size and shape affect the light absorption and scattering, 25 and the change of optical properties would result in the color variation. The size and shape of solution-derived crystalline particles is often influenced by the reaction temperature, which determines the nucleation and growth rates.…”

Simultaneous synthesis of hydroxyapatite fibres and β-tricalcium phosphate particles via a water controlled-release solvothermal process

“…The WCRSP forms the water molecules via an esterification reaction, as shown in reaction (1). [15][16][17]…”

“…The WCRSP forms the water molecules via an esterification reaction, as shown in reaction (1). 15–17 C 2 H 5 OH + CH 3 COOH → CH 3 COOC 2 H 5 + H 2 OReleased water molecules react with α-TCP particles and the HAp phase is formed on the particles. Simultaneously, solution pH decreases with an increase in the HAp formation, as shown in reaction (2).10Ca 3 (PO 4 ) 2 + 6H 2 O → 3Ca 10 (PO 4 ) 6 (OH) 2 + 2PO 4 3− + 6H + E10A10 samples showed a nearly equimolar reaction, and 0.17 mol of water is estimate to form via the esterification reaction of the WCRSP.…”

“…Yin et al reported the synthesis of homogeneous nanoparticles such as Cs x WO 3 nanorods via the WCRSP. [15][16][17] Because the amount of water supplied is suppressed, the WCRSP can be performed to synthesise various nanomaterials under highly supersaturated conditions, and this method is also expected to be effective for the synthesis of nanosized HAp. For this investigation, α-tricalcium phosphate (α-TCP) was selected as a starting material.…”

Nanoscale polymer discs, toroids and platelets: a survey of their syntheses and potential applications

“…The precision by which functional inorganic matter can be synthesised is extraordinary, with numerous, reliable procedures guaranteeing control over (nano)material characteristics in three dimensions. [10][11][12] Turning to soft matter, immense progress has been made in developing approaches to achieve polymer nanomaterials. Polymers are soft, and their chemistry and other properties are easily tuned to the desired application by synthetic procedures, making them outstanding building blocks for nanomaterials synthesis.…”