Hydrothermal Synthesis of SrTiO₃ Mesocrystals: Single Crystal to Mesocrystal Transformation Induced by Topochemical Reactions

Abstract

The mechanisms driving the mutual crystallographic alignment of nanocrystals in mesocrystals are various and not yet fully understood. As discussed in this paper, formation of mesocrystals can result from a topochemical reaction between single crystal particles or templates suspended in a liquid phase and ionic/molecular species in solution. In such a case, the initial particle morphology is retained in the final mesocrystal. If the transformation is not topotactic, the final product will maintain no memory of the precursor morphology. The magnitude of the lattice mismatch as well as the defective state of the precursor surface probably determine the degree of mutual crystallographic alignment of the nanocrystals which nucleate and grow on the substrate. Although identified by studying the hydrothermal crystallization of SrTiO3 from different single crystal titania precursors, this mechanism is very general and applicable to a variety of compounds and experimental situations, including solvothermal and molten salt syntheses.

Graphitic-C3N4 hybridized N-doped La2Ti2O7 two-dimensional layered composites as efficient visible-light-driven photocatalyst

“…N-doping does not change the sheet-like structure of LTO (Fig. 2b), which is attributed to the topochemical transformation between surface atoms of LTO crystals suspended in a liquid phase and TEOA molecular species in solution under hydrothermal condition [36][37][38]. The EDS analysis in Fig.…”

From Solute, Fluidic and Particulate Precursors to Complex Organizations of Matter

“…Here the temporal developments of distinct spatial patterns within the mineral particles reflect a potent spatiotemporal regulation of secondary nucleation achieved via the combined application of additives. Topochemical transformations also facilitate superstructured crystals, as evident by strontium titanate mesocrystals formed via single crystal anatase and SrTiO 3 mesocrystals grown from TiO 2 mesocrystals under hydrothermal conditions, (Figure c). Additives preferentially binding to crystal faces also govern particle co‐alignment and self‐association.…”

A surfactant-free route to synthesize Ba x Sr1−x TiO3 nanoparticles at room temperature, their dielectric and microwave absorption properties

“…Several chemical methods have been developed for the low-temperature preparation of micro-and nano-sized perovskite crystals such as molten salt synthesis [9][10], solvothermal and hydrothermal method [11][12][13][14][15][16][17], decomposition of bimetallic alkoxide precursors [18][19][20], microwave route [21][22][23][24], and biosynthesis [25]. Though these routes offer successful synthesis of perovskite nanoparticles with high quality and good crystalline, they usually require temperatures higher than 100°C or expensive reactants.…”