N3/Al2O3 composite nanochannels: photoelectric and photoelectric-and-pH cooperatively controlled ion gating

You Liu, Yan Kong, Xia Fan, Jin Zhai, Lei Jiang

Research output: Contribution to journalArticleResearchpeer-review

10 Citations (Scopus)

Abstract

Inspired by green chlorophyll pigments in photosynthetic systems that have the inherent ability to harvest solar energy and generate electrons, a photoelectric gated nanochannel system that efficiently converts photon energy into electricity with adjustable ionic conductivity is demonstrated. The nanochannel system is achieved by grafting photoresponsive ruthenium complex molecules (N3 molecules) onto bullet shaped Al2O3 nanochannels forming an organic/inorganic composite. The bullet shaped Al2O3 nanochannels working as an asymmetric rigid scaffold allow the composite nanochannels to mimic ionic current rectification (ICR) properties. The deprotonation of free carboxylic acid moieties on the N3 molecular backbone upon increasing the pH enhanced the surface charge density of the inner walls of the channels, which contributes to pH-tunable ion rectification. Furthermore, the excited state N3 molecule has a higher value for than that of the ground state pKa, thus resulting in a better photo-responsive capability of the nanochannels at higher pH values, which are used to develop a photoelectric-and-pH cooperatively controlled ion gating switch with better performance. At pH 7 and the photon-on state, the composite channel is in the ON state, while, at pH 4 and the photon-off state, the ion current is in the OFF state. This facile and environmentally friendly stimulus-responsive system may provide a new strategy to further design and develop future photon harvesting nanochannel systems for mimicking the more comprehensive process of photosynthesis.

Original languageEnglish
Pages (from-to)19220-19226
Number of pages7
JournalJournal of Materials Chemistry A
Volume5
Issue number36
DOIs
Publication statusPublished - 28 Sep 2017
Externally publishedYes

Cite this