梨形核壳结构氧化锌/银亚微米球的制备、表征及光学性能

利用亚锡离子还原银离子生成的金属银沉积在合成的梨形氧化锌表面作为晶种,进一步生长银纳米粒子,制备了梨形的、核壳结构的、单分散的氧化锌/银亚微米球。利用X射线衍射、透射电镜、能量色散X射线谱、紫外可见吸收谱及光致发光谱对所制备样品的形貌、微观结构、组成和光学性能进行了表征。结果表明:(1)样品是由梨形亚微米氧化锌核和银纳米颗粒壳组成;(2)在氧化锌表面的银纳米粒子作为光激发产生的电子捕获剂提高了光产生的载流子的分离效率,在能量没有改变的情况下减少了紫外发射光的强度,淬灭了可见发射光。

Preparation, Characterization and Optical Properties of Pear-Shaped ZnO/Ag Core-Shell Submicrospheres

Pear-shaped ZnO/Ag core-shell submicrospheres with good monodispersity were prepared via a seed-mediated particle growth method, where metallic Ag particles (reduction of Ag⁺ by Sn²⁺) deposited on ZnO submicrospheres were served as seeds (nucleation sites) for the further growth of Ag nanoshell overlayer. The as-prepared samples were characterized by transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, ultraviolet-visible absorption and photoluminescence measurement. The results demonstrate that the ZnO/Ag composites are composed of pear-shaped wurtzite ZnO submicrospheres and Ag nanoparticles. The results also indicate that the efficiency for separation of photoinduced electrons from holes is enhanced, the intensity of the UV emission is reduced without energy shifts, and the visible emission peak is quenched by Ag nanoparticles on ZnO.