Xiao Kai, Giusto Paolo, Chen Fengxiang, Chen Ruotian, Heil Tobias, Cao Shaowen, Chen Lu, Fan Fengtao, Jiang Lei
Max Planck Institute of Colloids and Interfaces, Department of Colloid Chemistry, Potsdam D-14476, Germany.
Key Laboratory of Bio-inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, Beijing 100191, China.
Natl Sci Rev. 2020 Sep 8;8(8):nwaa231. doi: 10.1093/nsr/nwaa231. eCollection 2021 Aug.
Light-driven ion (proton) transport is a crucial process both for photosynthesis of green plants and solar energy harvesting of some archaea. Here, we describe use of a TiO/CN semiconductor heterojunction nanotube membrane to realize similar light-driven directional ion transport performance to that of biological systems. This heterojunction system can be fabricated by two simple deposition steps. Under unilateral illumination, the TiO/CN heterojunction nanotube membrane can generate a photocurrent of about 9 μA/cm, corresponding to a pumping stream of ∼5500 ions per second per nanotube. By changing the position of TiO and CN, a reverse equivalent ionic current can also be realized. Directional transport of photogenerated electrons and holes results in a transmembrane potential, which is the basis of the light-driven ion transport phenomenon. As a proof of concept, we also show that this system can be used for enhanced osmotic energy generation. The artificial light-driven ion transport system proposed here offers a further step forward on the roadmap for development of ionic photoelectric conversion and integration into other applications, for example water desalination.
光驱动离子（质子）运输对于绿色植物的光合作用和一些古菌的太阳能收集而言都是一个至关重要的过程。在此，我们描述了如何利用TiO/CN半导体异质结纳米管膜来实现与生物系统类似的光驱动定向离子运输性能。这种异质结系统可以通过两个简单的沉积步骤来制备。在单侧光照下，TiO/CN异质结纳米管膜能够产生约9 μA/cm的光电流，这相当于每个纳米管每秒约有5500个离子的泵送流。通过改变TiO和CN的位置，还可以实现反向等效离子电流。光生电子和空穴的定向运输会产生跨膜电位，这是光驱动离子运输现象的基础。作为概念验证，我们还表明该系统可用于增强渗透能的产生。本文提出的人工光驱动离子运输系统在离子光电转换发展路线图以及集成到其他应用（例如水脱盐）方面又向前迈进了一步。
