Datta A, Priyam A, Bhattacharyya S N, Mukherjea K K, Saha A
UGC-DAE Consortium for Scientific Research, Kolkata Centre, India.
J Colloid Interface Sci. 2008 Jun 1;322(1):128-35. doi: 10.1016/j.jcis.2008.02.052. Epub 2008 Mar 4.
Size tunability of thiophenol capped CdS nanoparticles (NPs) has been achieved by controlling the temperatures in situ. Synthesis at 5 degrees C produced stable particles of smallest size having narrow size distribution and high photoluminescence quantum yield. The photoluminescence of thiophenol capped CdS NPs was quenched by the nitroaromatic compounds. The Stern-Volmer constant of dinitrobenzene was about 15-fold higher than nitrobenzene, which indicates that introduction of nitro groups in the benzene ring increases the quenching efficiency. Further, the as-prepared CdS NPs were found to display size dependent photocatalytic activity towards degradation of nitroaromatics. The catalytic efficiency of CdS quantum particles was quintupled with decrease in particle size from 5.8 to 3.8 nm. An empirical equation has been derived to correlate the catalytic efficiency of the nanoparticles with the twin factors operating in the quantum confinement regime: (i) change in surface to volume ratio and (ii) shift in conduction band edge.
通过原位控制温度实现了硫酚包覆的硫化镉纳米颗粒（NPs）的尺寸可调性。在5摄氏度下合成得到了尺寸最小、尺寸分布窄且光致发光量子产率高的稳定颗粒。硫酚包覆的硫化镉纳米颗粒的光致发光被硝基芳香化合物猝灭。二硝基苯的斯特恩-沃尔默常数比硝基苯高约15倍，这表明苯环中引入硝基会提高猝灭效率。此外，发现所制备的硫化镉纳米颗粒对硝基芳香化合物的降解表现出尺寸依赖性光催化活性。随着颗粒尺寸从5.8纳米减小到3.8纳米，硫化镉量子颗粒的催化效率提高了五倍。已经推导出一个经验方程，将纳米颗粒的催化效率与在量子限制区域起作用的两个因素相关联：（i）表面积与体积比的变化和（ii）导带边缘的移动。
