Photoresponsive Nanosheets of Polyoxometalates Formed by Controlled Self-Assembly Pathways
Photoresponsive Nanosheets of Polyoxometalates Formed by Controlled Self-Assembly Pathways
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DOI：
10.1002/anie.201612473
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发表时间：
2017-03-06
影响因子：
16.6
通讯作者：
Kimizuka, Nobuo
中科院分区：
文献类型：
--
作者：
Ishiba, Keita;Noguchi, Takao;Kimizuka, Nobuo
阴离子 Keggin 多金属氧酸盐 (POM) 和富含醚键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；单晶 X 射线衍射测量证明了这一点。初始条件的差异对能源景观中自组装路径的选择产生重大影响。在纯水中对 POM 片进行光照射会导致还原的 POM 溶解，从而可以使用激光扫描显微镜对纳米片进行位点特定蚀刻。相比之下，光刻在 AgNO3 水溶液中受到抑制，并且由于电子从光还原 POM 转移到纳米片表面的 Ag+ 离子，银纳米颗粒发生了位点选择性沉积。
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.