Synthesis of advanced ceramics by hydrothermal crystallization and modified related methods

Abstract

Abstract:The present article aims to give a brief overview about the advantages of the hydrothermal crystallization method for the synthesis of advanced ceramics. Emphasis is given, not only on the conventional hydrothermal crystallization, but also on some of its variants; such as ultrasound-assisted, electrochemical-assisted, microwave-assisted and surfactant-assisted hydrothermal methods which open up new opportunities for the synthesis of ceramic materials with novel properties demanded for advanced applications. In the current work the synthesis of barium titanate (BaTiO 3 ), lithium metasilicate (Li 2 SiO 3 ) and sodium-potassium niobate (Na, K)NbO 3 powders are reported as cases of study.

Magnetite thin film on mild steel formed by hydrothermal electrolysis for corrosion prevention

“…In this method, the growth solution was loaded in autoclaves, and [32]. At the beginning of the process as the temperature is increased, the hydrolysis of a metal salt precursor produces metal hydroxides.…”

“…Some interesting reaction behavior different to the general electrochemical reaction under ambient temperature and pressure has been confirmed for hydrothermal electrolysis [34,35]. The main advantages of this technique over the conventional hydrothermal method are improved purity of the products, lower reaction temperature and higher film growth rates [31,32]. This suggests that the method has some potential as a novel phenomenon and is different from the conventional reaction.…”

“…In order to improve the rate of the blackening process, the electrochemical process was employed [1,2,[27][28][29][30][31][32]. Bacsa et al [29] introduced the hydrothermal-electrochemical technique to synthesis barium titanate (BaTiO 3 ) at temperatures 80-200°C with titanium as an electrode and barium hydroxide (Ba(OH) 2 ) as an electrolyte solution.…”

Enhanced photocatalytic activity of ZnO nanoparticles grown on porous silica microparticles

“…These include the use of surfactants (Ortiz Landeros et al 2012;Zhang et al 2009), emulsification (Binks et al 2010;Noshirvani et al 2017) external forces (Bandekar et al 2014;Guo et al 2016;Sauter et al 2008) and the use of substrates (Miao et al 2007;Zhang, Xue and Wang 2002). In principle, nanoparticles synthesized on substrates will be fixed in space and agglomeration can be prevented (Sun and Sirringhaus 2006).…”

Influence of surface modifiers on hydrothermal synthesis of K x Na(1−x)NbO3

“…The reason seems to be that KNbO 3 and NaNbO 3 always form separately under hydrothermal conditions. It is known that Na reacts more readily with Nb to form NaNbO 3 than K to form KNbO 3 [13], then the conventional hydrothermal method presents certain difficulties to yield pure phases and compositional homogeneous products in one step, making it necessary to perform further thermal treatments [14].…”