In situ formation of zinc ferrite modified Al-doped ZnO nanowire arrays for solar water splitting

Solar water splitting by photoelectrochemical (PEC) cells is emerged as a promising route for H2 production. However, thus far no single component material can fulfill all the requirements for high efficiency PEC behavior, especially for the photoanode which conducts the water oxidation, while constructing a composite photoelectrode can result in improved performance. Herein, a simple wet-chemical treatment method is introduced to in situ fabricate ZnFe2O4 onto conductive Al:ZnO nanowire arrays for solar-driven water splitting. Benefiting from the high conductivity of Al:ZnO and the visible-spectrum absorption of ZnFe2O4, such a host–guest structure has finally led to an excellent photoelectrochemical performance with low onset potential (VRHE = 0.38 V) and a photocurrent density of 1.72 mA cm−2 (VRHE = 1.23 V). Notably, the low onset potential gives this structure great potential for application in unassisted light-driven tandem-type PEC cells.