Neat Polythiophene Film: Their Very High Photoelectrochemical Performance Allowing Completely Solar-Driven Water-Splitting

Abstract

π-Conjugated polymers are emerging as appealing photoelectrode materials for the photoelectrochemical hydrogen evolution reaction via water-splitting, which has otherwise been extensively explored using inorganic semiconductors. Herein we report the very high performance of a pure organic semiconductor film as a catalyst for hydrogen production via visible-light-driven water-splitting. The neat and unsubstituted polythiophene film, characterised with a well-filled grain morphology of the crystalline polymer, was prepared by a facile polymerisation method. The high photovoltage of 1.38 V vs. RHE at pH 12 enables solar-driven one-electron-per-photon water-splitting in combination with a traditional water-oxidation catalyst to produce hydrogen and oxygen separately. The very high photoelectrocatalytic hydrogen evolution rate of 1.02 mol(H2) h-1g-1 or 0.75 mA/cm2 at 0 V vs. RHE was also achieved with high durability. This study opens a new window for π-conjugated polymers for ultimately sustainable hydrogen production.