Novel properties and potential applications of functional ligand-modified polyoxotitanate cages

Abstract

Functional ligand-modified polyoxotitanate (L-POT) cages of the general type [TixOy(OR)z(L)m] (OR = alkoxide, L = functional ligand) can be regarded as molecular fragments of surface-sensitized solid-state TiO2, and are of value as models for studying the interfacial charge and energy transfer between the bound functional ligands and a bulk semiconductor surface. These L-POTs have also had a marked impact in many other research fields, such as single-source precursors for TiO2 deposition, inorganic-organic hybrid material construction, photocatalysis, photoluminescence, asymmetric catalysis and gas adsorption. Their atomically well-defined structures provide the basis for the understanding of structure/property relationships and ultimately for the rational design of new cages targeting specific uses. This highlight focuses on recent advances in L-POTs research, with emphasis on their novel properties and potential applications.

In Situ Self‐Assembled Polyoxotitanate Cages on Flexible Cellulosic Substrates: Multifunctional Coating for Hydrophobic, Antibacterial, and UV‐Blocking Applications

“…As shown in Figure , the UV transmission for 1|Cotton is around 10.9% at 350 nm and 4.8% at 300 nm, which is about 50 and 80% lower than that of the pristine cotton fabric at the same wavelengths. The observed transmission edge at 300–350 nm is the result of charge‐transfer from O(2p) to Ti(3d) in the precursor cage core of 1 , and is commonly observed in other POT cages reported in the literatures . The diffuse reflectance spectrum of 1|Cotton was also recorded.…”

“…Importantly, the photoinduced antibacterial activity is responsive to ambient light, which significantly enhances its practical viability. This could be due to the narrowed bandgap of 1 (2.95 eV) with Mn‐doping and Phen‐functionalization, in contrast to unmodified POT cages or TiO 2 nanomaterials that usually possess much wider bandgaps . The detailed antibacterial mechanism is likely to be complicated and will be subjected to further investigations .…”

“…With atomically well‐defined structures, polyoxotitanate (POT) cages with Ti x O y cores and organic ligand peripheries represent a unique family of titanium oxide species with versatile but synthetically controllable structural features . These POT cages can be prepared through one‐pot solvothermal synthesis from titanium alkoxide to generate single‐phase crystalline materials.…”

Polyoxometalates: Tailoring metal oxides in molecular dimension toward energy applications

“…Unconventional polyoxotitanate structures have been achieved, such as the fullerene‐like large polyoxotitanium cage [Ti 42 (μ 3 ‐O) 60 (O i Pr) 42 (OH) 12 )] 6− , with the quasi‐fullerene structures, good solubility, and interesting properties potentially available for particular optoelectronic applications relying on organic fullerenes. Various nanocomposites have been formed via the interaction between polyoxotitanates and nearby substrates, resulting in enhanced optoelectronic properties . Polyoxometalates modified with titanium dopants form composites with TiO 2 , altering the grain boundary structures of TiO 2 and improving the photoconductivity properties .…”

“…Various nanocomposites have been formed via the interaction between polyoxotitanates and nearby substrates, 142,143 resulting in enhanced optoelectronic properties. 144 Polyoxometalates modified with titanium dopants form composites with TiO 2 , altering the grain boundary structures of TiO 2 and improving the photoconductivity properties. 145 Polyoxotitanates with nitrogen doping exhibit effective dye degradation performance when they are functionalized with ligands.…”