Intrinsic Dipole-Field-Driven Mesoscale Crystallization of Core−Shell ZnO Mesocrystal Microspheres

Abstract

Novel uniform-sized, core-shell ZnO mesocrystal microspheres have been synthesized on a large scale using a facile one-pot hydrothermal method in the presence of the water-soluble polymer poly(sodium 4-styrenesulfonate). The mesocrystal forms via a nonclassical crystallization process. The intrinsic dipole field introduced by the nanoplatelets as a result of selective adsorption of the polyelectrolyte on some polar surfaces of the nanoparticles acts as the driving force. In addition, it plays an important role throughout the mesoscale assembly process from the creation of the bimesocrystalline core to the apple-like structure and finally the microsphere. Our calculation based on a dipole model confirms the dipole-field-driven mechanism forming the apple-like structure.

Metal oxide mesocrystals with tailored structures and properties for energy conversion and storage applications

“…This definition has been developed in recent years, where MCs are defined entirely according to their structures rather than their formation mechanism. 12 In this decade, a variety of MCs of metal oxides (for example, TiO 2 , [13][14][15][16][17][18][19][20][21][22][23] ZnO, [24][25][26][27][28][29][30][31][32][33][34] hematite (a-Fe 2 O 3 ), [35][36][37][38][39][40] maghemite (g-Fe 2 O 3 ), 41 Co 3 O 4 , 42 SnO, [43][44][45] Ag 2 O, 46 CuO [47][48][49] ), metal chalcogenides (for example, ZnS, 50,51 PbS, 52 PbSe 53,54 ), metals (for example, Au, 55 Ag, 56,57 Cu, 58 Pt, 59,60 Pd 61 ), organic compounds (for example, DL-alanine, 62,63…”

“…This definition has been developed in recent years, where MCs are defined entirely according to their structures rather than their formation mechanism. 12 In this decade, a variety of MCs of metal oxides (for example, TiO 2 , 13-23 ZnO, [24][25][26][27][28][29][30][31][32][33][34] Among metal oxides, TiO 2 is used in many applications that deal with environmental and energy problems (for example, photodegradation of pollutants, 67 water splitting for H 2 evolution, 68 dyesensitized solar cells 68 and lithium-ion batteries 69 ) owing to its …”

Influence of the Counterion on the Synthesis of ZnO Mesocrystals under Solvothermal Conditions

“…[5] Recently, it has been reported in the literature that ZnO can crystallize as mesocrystals. [6] A mesocrystal is a particle with a three-dimensional organization of primary nanocrystallites sharing a common crystallographic orientation. The formation of mesocrystals takes place, rather than through an ionby-ion attachment as in a classical crystallization process, via the incorporation of preformed primary particles by the socalled oriented attachment mechanism.…”

Nanocone Decorated ZnO Microspheres Exposing the (0001) Plane and Enhanced Photocatalytic Properties

“…A similar effect of the dipolar field leading to assembly of ZnO nanoparticles into twin polycrystalline particles or mesocrystal microspheres was previously observed. [13,35,36] Adv. Mater.…”