纳米硫化镉在对氨基苯硫酚自组装单层修饰金电极上的电化学合成

采用电流脉冲法在自组装了对氨基苯硫酚单层的金电极(PATP/Au)上电沉积硫化镉(CdS)纳米薄膜,运用扫描电子显微镜(SEM)和X射线衍射谱(XRD)对其形貌和结构进行了表征,发现得到的是垂直基底生长的CdS纳米棒有序阵列.研究电沉积中电流脉冲参数的影响时发现:随着电流脉冲宽度增大,CdS纳米棒的尺寸增大,有序性降低;脉冲幅度增大,则纳米棒尺寸增大,覆盖度也随之增大.因此通过调节脉冲宽度和脉冲幅度,可对所制备的CdS纳米薄膜的形貌和尺寸进行调控.运用循环伏安法和计时电位法对电沉积机理进行了探究.根据实验结果我们认为Au电极自组装PATP单分子层后,PATP分子中的-NH2与溶液中Cd2+相互作用,使沉积时的电子通过表面的PATP分子链进行传递.并进一步提出纳米CdS在PATP/Au电极上电化学合成的生长机理.

Electrochemical Synthesis of CdS Nanocrystals on a Gold Electrode Modified with a p-Aminothiophenol Self-Assembled Monolayer

This work describes the electrochemical synthesis of cadmium sulfide(CdS) nanostructured films by applying a pulsed current technique on the gold electrode modified with a self-assembled p-aminothiophenol monolayer(PATP/Au).Scanning electron microscopy(SEM) and X-ray diffraction(XRD) were used to characterize the morphology and crystal phase of the synthesized samples.An ordered array of CdS nanorods with a relatively higher c-axis preferred orientation was found on the PATP/Au substrate.The results indicated that the size of the CdS nanorods increased with the increase in the pulse width of the pulsed current,whereas the uniformity decreased.Furthermore,the size and coverage of the CdS nanorods increased with the increase in the pulse height.Thus,the morphology and size of the prepared CdS nanorods could be controlled by adjusting the pulse width and height.Cyclic voltammetry(CV) and chronopotentiometry were also applied to investigate the mechanism of the electrodeposition of CdS on PATP/Au.In accordance with the experimental results,we suggest that the interaction of the-NH2 in PATP molecules with Cd2+ in the solution may have contributed to the passing of electrons along the PATP chain following a modification of the p-aminothiophenol monolayer on the Au substrate.A formation mechanism for the electrochemically synthesized CdS nanorods on the PATP/Au substrate has consequently been proposed.