Enhancing the pure water splitting using carbon-iron oxide–carbon nitride (Fe₂O₃-C/CN) heterostructure

Highly efficient pure photocatalysts for water-splitting applications have long been plagued by structure imperfectness, narrowband light absorption, rapid charge recombination, and sluggish surface reaction kinetics. Herein we report a Z-scheme heterojunction photocatalyst made of Fe₂O₃, CN, and a conductive carbon layer (C) at the interface of the two materials (Fe₂O₃-C/CN). The structure has been characterized using a range of physicochemical and photo-electrochemical techniques. Compared to pristine Fe₂O₃, the Fe₂O₃-C/CN photocatalyst revealed superior photogenerated charge carriers, transport efficiency, and suppressed recombination process along with the conductive carbon layer acting as a mediator. The optimum composite of (5 wt% Fe₂O₃-C/CN) shows excellent activity towards pure water splitting, which reached 408 and 199 μmol/g.h for H₂ and O₂ evolution respectively, and a solar-to-hydrogen conversion efficiency of approximately 0.29 % when used for the pure water splitting process. Such a superior efficiency and production rate offer great potential for pure water splitting, and provide an alternative solution to future green energy production processes.