(111) Faceted Metal Oxides: A Review of Synthetic Methods

Abstract

Material design and synthesis have made tremendous impacts in the scientific community by unleashing a material's true potential via enhanced properties and applications. Over the years, advanced synthetic strategies have emerged and have been expanded to not only control the size and shape of nanoparticles but also to control the preferential growth of surface facets, paving the way for new materials with facet-dependent properties. Metal oxide (111) facets as compared to their potentially more stable counterpart facets (e.g., ( 100), ( 110)) have recently exhibited enriched chemical properties owing to their unique surface arrangement. As a result, metal oxide (111) faceted surfaces have been used in applications such as catalysis, sorbents, batteries, etc. This review aims to provide a perspective on the synthetic processes utilized to expose (111) surfaces and the governing factors/ synthetic parameters that expose them across various metal oxides of different crystal structures as well as some of their applications.

Oriented growth of stacking α-cobalt hydroxide salt continuous films and their topotactic-like transformation to oriented mesoporous films of Co3O4 and CoO

“…[33][34][35][36] In particular, the (111) plane has been reported to be more catalytically active for water splitting and CO oxidation than the (110) and (100) planes. [37][38][39] Therefore, due to the topotactic relationship of Co-LHS[001]//Co x O y [111],…”

“…[33][34][35][36] In particular, the (111) plane has been reported to be more catalytically active for water splitting and CO oxidation than the (110) and (100) planes. [37][38][39] Therefore, due to the topotactic relationship of Co-LHS[001]//Co x O y [111], [001]oriented Co-LHS lms are an attractive candidate to spontaneously provide a myriad of oriented Co x O y nanocrystals with the (111) exposed plane. Co-LHSs can be grown directly on substrates via electrochemical deposition in aqueous solution.…”

The Overlooked Potential of Sulfated Zirconia: Reexamining Solid Superacidity Toward the Controlled Depolymerization of Polyolefins

“…While repeated, symmetric atomic planes do not typically generate a polar, catalytically active metal oxide surface, the slightly distorted structure of tetragonal zirconia has several stable facets with significant dipole moments and surface energy. Still, higher surface energy facets are more unstable, meaning only a select few are likely to be exposed in practice. ,, The most common nonequivalent facets observed by TEM for unsulfated tetragonal zirconia are (101), (001), and (100), matching Bravais–Friedel–Donnay–Harker theory. Based on computationally determined surface energy determined by Piskorz et al (Figure ii), the relaxed surface energies of the relatively stable tetragonal zirconia facets that could be exposed should be ordered as (101) < (001) < (100) < (111) < (110), with higher-surface-energy facets generally having lower coordination number zirconium and oxygen atoms .…”

“…186 Since water can promote the solvothermal growth of nanoparticles in specific directions by stabilizing high surface energy facets like other chemical additives (i.e., surfactants, ions, polymers) and sulfates enhance thermal stability of tetragonal zirconia, perhaps sulfation promotes growth of the (111) and ( 110) facets as well. 208,209 Unfortunately, few conventionally prepared, well-faceted SZrO samples have been characterized by TEM. Benai ̈ssa et al provided some of the highest-resolution TEM analysis of SZrO with well-faceted tetragonal particles and minimal defects at plane terminations, though it appears facet assignments were made based only on crystallographic orientation and d-spacing.…”

Recent Advances in Magnetite Crystallization: Pathway, Modulation, and Characterization

“…Magnetite (Fe 3 O 4 ) is a versatile crystalline material with multiple functional properties, including magnetism, biocompatibility, and catalytic activity. It has been extensively applied in industries such as sensing, energy storage, hydrometallurgy, , environmental remediation, − and biological applications. − The performance of magnetite crystals in specific applications depends essentially on the physicochemical properties of crystals, ,− including size (distribution), ,− morphology, ,− structure, − and magnetism. , Precise control of these properties can be achieved by adjusting thermodynamic or kinetic parameters during the nucleation and growth of magnetite. ,− Therefore, comprehensively investigating the crystallization process of magnetite would provide a solid foundation for designing and synthesizing materials with the desired properties.…”