In-situ coating of multifunctional FeCo-bimetal organic framework nanolayers on hematite photoanode for superior oxygen evolution

Owing to the high theoretical photocurrent density, the hematite (alpha-Fe2O3) based photoanode has been intensively concerned in photoelectrochemical (PEC) water splitting, but its serious charge recombination and sluggish water oxidation kinetics are still the stumbling blocks. This work reports a high-performance Fe2O3-based photoanode achieved by coating multifunctional FeCo-bimetal organic framework (MOF) nanolayers (NLs) on Fe2O3 nanoarrays via an in-situ solvothermal process. The FeCo MOF NLs introduced not only effectively passivate the surface states of Fe2O3 photoanode and boost the water oxidation kinetics serving as the cocatalyst, but also construct p-n heterojunctions with Fe2O3 to accelerate the directional migration and separation of photogenerated charge carriers. Expectedly, the as-obtained FeCo-MOF/Fe2O3 photoanode exhibits an apparent negative shift of onset potential, an excellent long-term PEC stability, and highly improved photocurrent density. This finding provides a novel and effective strategy to introduce advanced multifunctional surface coating for enhancing the PEC performance of photoelectrodes.

Automated summary

This study presents a high-performance Fe2O3-based photoanode achieved by coating FeCo-MOF nanolayers on Fe2O3 nanoarrays, which effectively enhances the surface states of the photoanode and boosts the water oxidation kinetics.