Monolayered Nanodots of Transition Metal Oxides
Monolayered Nanodots of Transition Metal Oxides
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DOI：
10.1021/ja400443a
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发表时间：
2013-03-20
影响因子：
15
通讯作者：
Imai, Hiroaki
中科院分区：
文献类型：
--
作者：
Nakamura, Keisuke;Oaki, Yuya;Imai, Hiroaki
钛、钨和锰氧化物的单层纳米点是通过室温下的水溶液工艺剥离纳米晶体而获得的。层状化合物的前驱体纳米晶，如钛酸钠（Na0.80Ti1.80方形O-0.2(4)中心点xH(2)O，方形：空位（x < 1.17））、钨酸铯（Cs4W11O35中心点yH(2)O（y < 10.5））、锰酸钠（Na0.44MnO2 中心点 zH(2)O (z < 0.85)）在水溶液中合成。通过在层间空间中引入大体积有机阳离子，这些层状化合物的纳米晶体分层成单层纳米点。所得横向尺寸为 2-5 nm 的钛酸盐和钨酸盐单层纳米点显示出带隙能量的显着蓝移。计算研究支持带隙能量的蓝移。结果表明，单层纳米点的合成可以扩大基于尺寸效应的性能调节范围。目前用于生成超薄微小物体的方法可以应用于各种纳米材料。
Monolayered nanodots of titanium, tungsten, and manganese oxides were obtained by exfoliation of the nanocrystals through aqueous solution processes at room temperature. The precursor nanocrystals of the layered compounds, such as sodium titanate (Na0.80Ti1.80 square O-0.2(4)center dot xH(2)O, square: vacancy (x < 1.17)), cesium tungstate (Cs4W11O35 center dot yH(2)O (y < 10.5)), and sodium manganate (Na0.44MnO2 center dot zH(2)O (z < 0.85)), were synthesized in an aqueous solution. These nanocrystals of the layered compounds were delaminated into the monolayered nanodots through introduction of a bulky organic cation in the interlayer space. The resultant monolayered nanodots of the titanate and tungstate 2-5 nm in lateral size showed a remarkable blueshift of the bandgap energies. The calculation studies supported the blueshifts of the bandgap energies. The results suggest that syntheses of monolayered nanodots can expand the tuning range of the properties based on size effect The present approaches for generation of ultrathin tiny objects can be applied to a variety of nanomatetials.