Efficient Conjugated Polymer-Methyl Viologen Electron Transfer System for Controlled Photo-Driven Hydrogen Evolution.

Photodriven hydrogen production has been a good strategy in solar energy utilization. In this work, we use a water-soluble negatively charged polythiophene derivative as photosensitizer to produce hydrogen from aqueous solution containing methyl viologen (MV2+), ethylenediaminetetraacetic acid disodium salt (EDTA), and a colloidal platinum catalyst upon exposure to xenon lamp (>420 nm) or natural sunlight. The supramolecular assembly and dis-assembly processes of MV2+ and cucurbit[8]uril (CB[8]) was further used to reversibly "turn-on" and "turn-off" hydrogen generation of the polymer system. This research offers a proof-of-concept to control hydrogen generation in demand, which is an advantage for hydrogen utilization and storage.