Photoinduced electron accumulation in colloidally dispersed wide band-gap semiconductor nanosheets.
Photoinduced electron accumulation in colloidally dispersed wide band-gap semiconductor nanosheets.
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DOI：
10.1016/j.jcis.2010.10.026
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发表时间：
2011-02
影响因子：
9.9
通讯作者：
T. Nakato;Yoshimi Yamada;Mari Nakamura;Atsushi Takahashi
中科院分区：
文献类型：
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作者：
T. Nakato;Yoshimi Yamada;Mari Nakamura;Atsushi Takahashi
我们研究了层状hexaniobate，被称为光催化活性的宽带隙半导体的胶体系统中的光诱导电子积累，并试图通过引入添加剂到胶体中控制的光响应。通过层状氧化物的剥离获得无机纳米片。胶体的紫外线照射导致电子在纳米片中积累，产生还原的铌酸盐物质。丙基铵离子作为剥离剂引入，并作为反离子的反式纳米片被指示为电子供体，稳定的电子积累状态。通过添加适量的光化学惰性粘土纳米片，还原的酒石酸盐物种的产率和半衰期大大增加，而通过添加分子电子供体如EDTA和三乙醇胺，它们仅增加一点点。此外，分子物种减弱了粘土纳米片的增强效果。结果表明，半导体纳米片与添加剂之间的直接相互作用并不能解释光化学反应的发生，而是受胶体结构控制的胶体组分之间的间接相互作用的影响。
We investigated photoinduced electron accumulation in a colloidal system of layered hexaniobate that is known as a photocatalytically active wide band-gap semiconductor, and attempted to control the photoresponse by introducing additives into the colloid. The inorganic nanosheets were obtained by exfoliation of the layered oxide. UV-irradiation of the colloids led to electron accumulation in the nanosheets to generate reduced niobate species. Propylammonium ions introduced as the exfoliating reagent and present as the counter ions of niobate nanosheets were indicated as the electron donor that stabilized the electron-accumulating state. Yield and half-life of the reduced niobate species greatly increased by adding an appropriate amount of photochemically inert clay nanosheets, while they increased only a little by the addition of molecular electron donors such as EDTA and triethanolamine. Moreover, the molecular species diminished the enhancement effect of the clay nanosheets. The results suggested that the photochemical event was not explained by direct interactions between the semiconductor nanosheets and the additives at molecular level but governed by indirect interactions between the colloid components regulated by the colloid structure.