Artificial Ion Channels Regulating Light-Induced Ionic Currents in Photoelectrical Conversion Systems

摘要

In living organisms, biological ion channels open and close in response to various stimuli from surroundings to regulate ionic exchange through the cell membrane. But natural ion channels can only function in a fragile environment (the lipid bilayer), which limits their applications. Inspired by nature, many abiotic nanogating devices, which are called artificial ion channels, have been synthesized, such as meso-structured silica, alumina, or titania nanochannel arrays, track-etching polymer films, quartz nanopipettes, colloidal composite films, carbon nanotubes, ion- or electron-beam-etched silicon nitride and oxide films, etc. They control fluids through them in nanoconfined geometries. The polyethylene terephthalate (PET) nanoporous membrane is a kind of artificial polymeric ion channels. Due to the regular shape of the nanochannel, the narrow distribution of the channel size and the available surface group for modification, the PET nanochannel has applied to fabricate various nanogating devices to respond to a single stimulus, such as pH, temperature, specific ions or biomolecules, or to dual stimuli, such as pH and light. In recent years, single or multiple PET nano-channels have been applied in energy conversion systems. In these systems, PET nanochannels regulate the process of the conversion from mechanical energy, light, concentration gradient, etc., towards electricity, with their specific ionic transportation properties.