Anion-Exchange\nMembrane–Photoelectrochemical\nWater Splitting Using Porous Hematite Photoanodes

Abstract

The requirement for liquid electrolytes\nto maintain their\nionic\nconductivity hinders the practical implementation of photoelectrochemical\n(PEC) systems. Here, a membrane electrode assembly was fabricated\nby incorporating porous α-Fe₂O₃ (hematite)-based\nphotoanodes with an anion-exchange membrane (AEM). AEM–PEC\nwater splitting was demonstrated in pure water without supporting\nelectrolytes over porous hematite photoanodes under visible-light\nirradiation. This PEC system was operational even under low conductivity\nand near-neutral conditions (∼1 mS/m and pH ∼ 9). Action\nspectral analysis confirmed a visible-light response extending up\nto 600 nm, surpassing that of previously reported photoelectrodes\nwith solid-electrolyte membranes.