Photocatalytic activity of highly porous zinc ferrite prepared from a zinc-iron(III)-sulfate layered double hydroxide precursor

A zinc-iron(III)-sulfate layered double hydroxide (LDH) has been prepared from zinc and iron(II) precursors. Calcination at 500degreesC or above affords a mixture of ZnO (zincite) and ZnFe2O4 (spinel) phases. Treatment of the calcined products with aqueous NaOH leads to dissolution of the ZnO and the formation of a pure zinc ferrite phase with high surface area and pore volume. When used as a photocatalyst for the degradation of phenol, the active lifetime of the catalyst was extended compared with a sample of zinc ferrite prepared by a conventional co-precipitation route followed by calcination under the same conditions. The highly porous material also exhibited a higher selectivity to low molecular weight oxidation products than the co-precipitated catalyst.