Photoresponsive Nanosheets of Polyoxometalates Formed by Controlled Self-Assembly Pathways.
Keita IshibaTakao NoguchiHiroaki IguchiMasa-Aki MorikawaKenji KanekoNobuo KimizukaPublished in: Angewandte Chemie (International ed. in English) (2017)
Anionic Keggin polyoxometalates (POMs) and ether linkage-enriched ammonium ions spontaneously self-assemble into rectangular ultrathin nanosheets in aqueous media. The structural flexibility of the cation is essential to form oriented nanosheets; as demonstrated by single-crystal X-ray diffraction measurements. The difference in initial conditions exerts significant influence on selecting for self-assembly pathways in the energy landscape. Photoillumination of the POM sheets in pure water causes dissolution of reduced POMs, which allowed site-specific etching of nanosheets using laser scanning microscopy. By contrast, photoetching was suppressed in aqueous AgNO3 and site-selective deposition of silver nanoparticles occurred as a consequence of electron transfer from the photoreduced POMs to Ag+ ions on the nanosheet surface.
Keyphrases
- quantum dots
- ionic liquid
- silver nanoparticles
- metal organic framework
- reduced graphene oxide
- highly efficient
- high resolution
- electron transfer
- visible light
- electron microscopy
- magnetic resonance
- transition metal
- high speed
- single molecule
- genome wide
- high throughput
- computed tomography
- gene expression
- dna methylation
- magnetic resonance imaging
- high efficiency
- mass spectrometry
- water soluble
- solid state
- crystal structure