Novel design of photocatalyst coaxial ferromagnetic core and semiconducting shell microwire architecture

•Novel design of coaxial core-shell magnetic-semiconductor microwire.•The core is a ferromagnetic metal and the shell is a semiconducting hematite layer.•The core gives mechanical stability and collect the generated photoelectrons.•This nano/micro device has exhibited photocatalytic activity.•The architecture can be designed as a photoanode to drive water oxidation reaction.