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

Abstract

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 (V_RHE = 0.38 V) and a photocurrent density of 1.72 mA cm⁻² (V_RHE = 1.23 V). Notably, the low onset potential gives this structure great potential for application in unassisted light-driven tandem-type PEC cells.