Morphology dependent photocatalytic efficacy of zinc ferrite probed for methyl orange degradation

Abstract

Zinc ferrite (ZnFe 2 O 4 ) photocatalysts with different morphologies (sizes and shapes) were synthesized to explore the effect of morphology on their photocatalytic efficiency. The results obtained using field emission scanning electron microscopy (FESEM) revealed that the obtained samples had the needle-, cube-, granule-and plate-like morphology, labeled as NZFO, CZFO, GZFO and PZFO, respectively. X-ray diffraction (XRD) patterns showed that all the samples had the spinel structure of ZnFe 2 O 4 without any other impurities. The calculated average crystallite size followed the order NZFO<GZFO<CZFO< <PZFO. The surface area was inversely proportional to the average crystallite size and followed the order NZFO>GZFO>CZFO>PZFO. The photocatalytic efficiency for the degradation of methyl orange also followed the order NZFO> >GZFO>CZFO>PZFO. The morphology-dependent photocatalytic efficiency of ZnFe 2 O 4 was closely related with its crystallite size and surface area. The smaller the crystallite size was, the larger the surface area was, and the higher the photocatalytic efficiency was.