Park Soo Ik, Jung Sung-Mok, Kim Jae-Yup, Yang Jiwoong
Department of Energy Science and Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988, Korea.
Department of Chemical Engineering, Dankook University, Yongin 16890, Korea.
Materials (Basel). 2022 Aug 31;15(17):6010. doi: 10.3390/ma15176010.
Semiconductor nanocrystal quantum dots (QDs) are promising materials for solar energy conversion because of their bandgap tunability, high absorption coefficient, and improved hot-carrier generation. CuInSe (CISe)-based QDs have attracted attention because of their low toxicity and wide light-absorption range, spanning visible to near-infrared light. In this work, we study the effects of the surface ligands of colloidal CISe QDs on the photoelectrochemical characteristics of QD-photoanodes. Colloidal CISe QDs with mono- and bifunctional surface ligands are prepared and used in the fabrication of type-II heterojunction photoanodes by adsorbing QDs on mesoporous TiO. QDs with monofunctional ligands are directly attached on TiO through partial ligand detachment, which is beneficial for electron transfer between QDs and TiO. In contrast, bifunctional ligands bridge QDs and TiO, increasing the amount of QD adsorption. Finally, photoanodes fabricated with oleylamine-passivated QDs show a current density of ~8.2 mA/cm, while those fabricated with mercaptopropionic-acid-passivated QDs demonstrate a current density of ~6.7 mA/cm (at 0.6 V under one sun illumination). Our study provides important information for the preparation of QD photoelectrodes for efficient photoelectrochemical hydrogen generation.
半导体纳米晶体量子点（QDs）因其带隙可调性、高吸收系数和改善的热载流子产生而成为太阳能转换的有前途的材料。基于铜铟硒（CISe）的量子点因其低毒性和从可见光到近红外光的宽光吸收范围而受到关注。在这项工作中，我们研究了胶体CISe量子点的表面配体对量子点光阳极光电化学特性的影响。制备了具有单官能和双官能表面配体的胶体CISe量子点，并通过将量子点吸附在介孔TiO上用于制备II型异质结光阳极。具有单官能配体的量子点通过部分配体脱离直接附着在TiO上，这有利于量子点与TiO之间的电子转移。相比之下，双官能配体桥接量子点和TiO，增加了量子点的吸附量。最后，用油酸胺钝化的量子点制备的光阳极显示出约8.2 mA/cm的电流密度，而用巯基丙酸钝化的量子点制备的光阳极在一个太阳光照下0.6 V时的电流密度为约6.7 mA/cm。我们的研究为制备用于高效光电化学制氢的量子点光电极提供了重要信息。
