Abstract
Hydrous TiO2 colloidal spheres (HTCS) derived from the direct precipitation of titanium alkoxides have attracted continuous interests since 1982. Entering the 21st century, rapid progress in the development of structure-directing agents (SDAs) have enabled reproducible and size-controllable synthesis of highly uniform HTCS with diameters in the nano- to micro-meter range. The availability of various HTCS provides versatile self-templating platforms for the targeted synthesis of nanoporous TiO2 and titanate spheres with tunable composition, crystallographic phases, and internal structures for a variety of advanced photo/electrochemical applications. This review provides a historical overview for the evolution of HTCS, along with an insightful discussion for the formation mechanism of self-assembly of HTCS during the sol-gel process. Key synthetic parameters including SDA, solvent, reaction temperature and water dosage are discussed for the size and morphology control of HTCS with predictable textural properties. Then, we describe the synthetic strategies of nanoporous TiO2 and titanate spheres using various HTCS as self-templates. Here, the focus lies on the interactions between TiO2 nanobuilding blocks with precursors or media at the solid/liquid and solid/solid interfaces, the concurrent phase transitions, and the microstructural and morphological evolutions. Selective formation of crystal phase and internal structures (e.g., solid, hollow, core-shell, yolk-shell) are discussed by manipulating the crystallization kinetics. To further elucidate the composition-structure-property-performance relationship for the resulting nanoporous TiO2 and titanate spheres, their applications in photo(electro)catalysis, mesoscopic solar cells, and lithium-ion batteries are scrutinized. Finally, we share opinions on key challenges and perspectives for the future controllable preparation, formation mechanisms, and applications of HTCS and their crystalline derivatives.
Dokumententyp: | Zeitschriftenartikel |
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Fakultät: | Chemie und Pharmazie > Department Chemie |
Themengebiete: | 500 Naturwissenschaften und Mathematik > 540 Chemie |
ISSN: | 0001-8686 |
Sprache: | Englisch |
Dokumenten ID: | 100298 |
Datum der Veröffentlichung auf Open Access LMU: | 05. Jun. 2023, 15:34 |
Letzte Änderungen: | 05. Jun. 2023, 15:34 |