Preparation of Metal Sulfide Composite Ultrafine Particles in Reverse Micellar Systems and Their Photocatalytic Property
Preparation of Metal Sulfide Composite Ultrafine Particles in Reverse Micellar Systems and Their Photocatalytic Property
复制标题
反胶束体系金属硫化物复合超细颗粒的制备及其光催化性能
DOI：
10.1252/jcej.27.590
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发表时间：
1994
影响因子：
0.8
通讯作者：
I. Komasawa
中科院分区：
文献类型：
--
作者：
T. Hirai;S. Shiojiri;I. Komasawa
以AOT/异辛烷反胶束溶液中的纳米级水池为反应介质制备了CdS、ZnS及其复合超微粒子。通过改变反胶束溶液中的水含量Wo（=[H2O]/[AOT]）来控制超微粒子的尺寸，而这几乎与Cd ~（2+）、Zn ~（2+）和S ~（2-）的进料浓度无关。可以在小于8的Wo值下制备稳定的超细颗粒，其不引起过度聚集并且其带隙在形成后长时间持续大于体半导体的带隙。将同时含有Cd ~（2+）和Zn ~（2+）的胶束溶液与S ~（2-）溶液混合，得到共沉淀的半导体超碱粒子。ZnS在含有CdS微粒的胶束溶液中逐渐沉淀得到ZnS包覆的CdS超微粒子。使用过量的S2-沉淀是有效的，在使所得颗粒的组成接近于初始溶液的组成，并且还避免了混合晶体的形成。由此制备的复合超微粒子可直接应用于光催化还原水，并发现其光催化活性相比CdS颗粒有所改善。共沉淀粒子的光催化性能根据粒子的带隙而变化。
CdS, ZnS and their composite ultrafine particles were prepared using nanometer-sized waterpools in AOT/isooctane reverse micellar solutions as reaction media. The size of the ultrafine particles was controlled by changing the water content Wo (=[H2O]/[AOT]) of the reverse micellar solution and this was almost independent of the feed concentrations of Cd2+, Zn2+ and S2–. Stable ultrafine particles, which do not cause excess aggregation and the band gap of which continues to be larger than that of the bulk semiconductor for a long time after formation, could be prepared at a value of Wo less than 8. Mixing a micellar solution containing both Cd2+ and Zn2+ with a solution of S2– gave coprecipitated semiconductor ultrarine particles. Gradual precipitation of ZnS in a micellar solution which had contained CdS particles gave ZnS-coated CdS ultrafine particles. The use of an excess of S2– for precipitation was effective in making the composition of the resulting particles close to that of the initial solution, and also avoided the formation of mixed crystals. The composite ultrafine particles thus prepared could be directly applied to the photocatalytic reduction of water and were found to be improved in their photocatalytic activity compared to CdS particles. The photocatalytic properties of the coprecipitated particles varied according to the particle band gap.