Interfacial‐Potential‐Gradient Induced a Significant Enhancement of Photoelectric Conversion: Thiophene Polyelectrolyte (PTE‐BS) and Bipyridine Ruthenium (N3) Cooperative Regulated Biomimetic Nanochannels

Abstract Inspired by photosynthesis, the ion transport‐based artificial light harvesting system shows unprecedented superiority in photoelectric conversion. However, how to high‐efficiently utilize solar energy, just like photosystem I and photosystem II working together in the thylakoid membrane, remains a great challenge. Here, a facile strategy for patterning two photosensitive molecules is demonstrated, that is, thiophene polyelectrolyte (PTE‐BS) and bipyridine ruthenium (N3), onto the two segments of symmetric/asymmetric hourglass‐shaped alumina nanochannels. Owing to the different energy levels, an interfacial‐potential‐gradient is established in the tip junction of the nanochannels, wherein photoinduced excited electrons transfer from PTE‐BS to N3, resulting in the efficient separation of electron–holes. Simultaneously, the increasing surface‐charge‐density enhances transmembrane ion transport performance. Thus, the photo‐induced ionic current change ratio increases up to 100% to realize a significant photoelectric conversion, which is superior to all of the N3 or PTE‐BS individually modified nanochannel systems. By changing the channel geometry from symmetric to asymmetric, the biomimetic nanochannels also exhibit a diode‐like ion transport behavior. This work may provide guidance for the development of high‐performance photoelectric conversion nanochannel systems.