Institute of Innovative Science and Technology, Tokai University , Hiratsuka, Kanagawa 259-1292, Japan.
Langmuir. 2017 Jul 5;33(26):6457-6463. doi: 10.1021/acs.langmuir.7b00878. Epub 2017 Jun 22.
Owing to their high extinction coefficient and moderate band gap, cadmium chalcogenides are known as common semiconductors for photoelectric conversion. Nevertheless, no ideal cadmium chalcogenide with proper band structure is available yet for photoelectrochemical hydrogen evolution. In this work, we modified the band structure of CdTe via alloying with Se to achieve a ternary compound (CdSeTe) with n-type conduction, a narrower band gap, and a more negative band position compared to those of CdSe and CdTe. This novel material exhibits strong light absorption over a wider spectrum range and generates more vigorous electrons for hydrogen reduction. As a result, a photoelectrode based on nanoflake arrays of the new material could achieve a photocurrent density 2 times that of its CdSe counterpart, outperforming similar materials previously reported in the literature. Moreover, the quick transfer of holes achieved in the novel material was found to depress photocorrosion processes, which led to improved long-term working stability.
由于其高消光系数和适中的带隙，碲镉汞被认为是光电转换的常见半导体。然而，目前还没有理想的具有适当能带结构的碲镉汞用于光电化学析氢。在这项工作中，我们通过与硒合金化来修饰 CdTe 的能带结构，从而获得了一种具有 n 型导电性的三元化合物（CdSeTe），与 CdSe 和 CdTe 相比，其带隙更窄，带位置更正。与 CdSe 相比，这种新型材料在更宽的光谱范围内具有更强的光吸收能力，并产生更活跃的电子用于还原氢气。因此，基于该新材料的纳米片阵列的光电极可以实现 2 倍于 CdSe 的光电流密度，优于文献中先前报道的类似材料。此外，在新型材料中实现的空穴的快速转移被发现抑制了光腐蚀过程，从而提高了长期工作稳定性。
