Effect of Zinc Acetate Concentration on Optimization of Photocatalytic Activity of p-Co 3O 4/ n-ZnO Heterostructures

摘要

In this work, p -Co~(3)O~(4)/ n -ZnO heterostructures were fabricated on Ni substrate by hydrothermal-decomposition method using cobaltous nitrate hexahydrate (Co(NO~(3))~(2)·6H~(2)O) and zinc acetate dihydrate (Zn(CH~(3)COO)~(2)·2H~(2)O) as precursors with zinc acetate concentration varying from 5.0 to 55.0?mM. Structure and morphology of the developed samples were characterized by X-ray diffraction (XRD), Raman spectroscopy, and scanning electron microscopy (SEM). Effect of zinc acetate concentration on the photocatalytic activity of p -Co~(3)O~(4)/ n -ZnO heterostructures was investigated by degradation of methyl orange (MO) under the UV light irradiation. The fabricated p -Co~(3)O~(4)/ n -ZnO heterostructures exhibited higher photocatalytic activity than pure Co~(3)O~(4)particles. In order to obtain the maximum photocatalytic activity, zinc acetate concentration was optimized. Specifically, at 35?mM of zinc acetate, the p -Co~(3)O~(4)/ n -ZnO showed the highest photocatalytic activity with the degradation efficiency of MO reaching 89.38% after 72?h irradiation. The improvement of photocatalytic performance of p -Co~(3)O~(4)/ n -ZnO heterostructures is due to the increased concentration of photo-generated holes on Co~(3)O~(4)surface and the higher surface-to-volume ratio in the hierarchical structure formed by nano-lamellas. Graphical abstract.