Department of Chemistry and Biochemistry, Graduate School of Engineering, Center for Molecular Systems (CMS), Kyushu University, 744 Moto-oka Nishi-ku, Fukuoka, 819-0395, Japan.
Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Sendai, 980-8578, Japan.
Angew Chem Int Ed Engl. 2017 Mar 6;56(11):2974-2978. doi: 10.1002/anie.201612473. Epub 2017 Feb 15.
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 AgNO 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.
阴离子 Keggin 多金属氧酸盐 (POM) 和醚键丰富的铵离子在水介质中自发自组装成矩形超薄纳米片。阳离子的结构灵活性对于形成定向纳米片至关重要；这一点通过单晶 X 射线衍射测量得到了证明。初始条件的差异对能量景观中自组装途径的选择有显著影响。在纯水中对 POM 片进行光照射会导致还原的 POM 溶解，这使得可以使用激光扫描显微镜对纳米片进行特定位置的蚀刻。相比之下，在含有 AgNO 的水溶液中光蚀刻受到抑制，并且由于光还原的 POM 向纳米片表面上的 Ag 离子的电子转移，发生了银纳米粒子的选择性沉积。
