Photochemical effect on reduction of ultrafine (Ni, Zn) ferrite by CO at 300°C

Abstract

Reduction of ultrafine Zn^II ferrite (ZF), (Ni, Zn) ferrite (NZF) and Ni^II ferrite (NF) with CO was carried out under ultraviolet (UV) irradiation at 300°C to investigate photochemical effects on the redox reaction of ferrites. The rate of reduction of ZF, NZF and NF was increased (130% at maximum) by irradiating with UV light. The electron–hole pairs formed by absorption of the UV light are considered to diffuse thermally to the surface of the ferrite and to assist the reduction of the ferrite at 300°C. The photochemical reduction rate of NZF was larger than those for NF and ZF. The maximal quantum efficiency of the photochemical reduction of NZF was 0.6%.