Clean Energy Research Centre, Korea Institute of Science and Technology, Seoul 130-650, Republic of Korea.
J Colloid Interface Sci. 2013 Jul 15;402:94-9. doi: 10.1016/j.jcis.2013.03.049. Epub 2013 Apr 8.
The photoefficiency of CdS/TiO2 electrodes can be enhanced by employing efficient method of CdS sensitization from which, the contact area, thickness of CdS layer, and the recombination of photoelectrons with electrolyte can be controlled. Here, we demonstrate a simple solvothermal approach of CdS quantum dots (QDs) sensitization on TiO2 nanoparticle (NP) film coated on FTO. Our new approach prevents the clogging of CdS QDs and promotes uniform deposition of QDs throughout the mesoporous TiO2 NP film. The sensitization of CdS can be controlled by the reaction time and the concentration of the precursors. The solvothermally sensitized photoanodes exhibit enhanced photocurrents and fill factors and improved photostability in aqueous solution compared to the one prepared by a conventional SILAR method. Open-circuit potential decay measurement under shutting off illumination shows that the lifetime of photoelectron is extended with solvothermally prepared CdS layer, indicating efficient suppression of recombination of the accumulated electron in TiO2 to the electrolyte. This methodology can be applied in making more efficient heterojunctions consisting of CdS and other wide band gap oxide semiconductors which could improve charge separation and mitigate charge recombination for photoelectrochemical applications.
CdS/TiO2 电极的光电效率可以通过采用有效的 CdS 敏化方法来提高，通过这种方法可以控制接触面积、CdS 层的厚度以及光电子与电解质的复合。在这里，我们展示了一种在 FTO 上涂覆 TiO2 纳米粒子（NP）薄膜的 CdS 量子点（QD）敏化的简单溶剂热方法。我们的新方法防止了 CdS QD 的堵塞，并促进了 QD 在整个介孔 TiO2 NP 薄膜中的均匀沉积。CdS 的敏化可以通过反应时间和前体浓度来控制。与通过传统 SILAR 方法制备的光阳极相比，溶剂热敏化的光阳极在水溶液中表现出增强的光电流和填充因子以及提高的光电稳定性。关闭光照下的开路电位衰减测量表明，通过溶剂热法制备的 CdS 层延长了光电子的寿命，表明有效地抑制了 TiO2 中积累的电子与电解质的复合。这种方法可以应用于制备由 CdS 和其他宽带隙氧化物半导体组成的更高效的异质结，这可以改善光电化学应用中的电荷分离并减轻电荷复合。
