Synthesis of ZnO nanoparticles and ZnO/PAN composite materials for photocatalytic and antibacterial applications

Abstract

Zinc oxides (ZnO) are used as a pigment and in sunscreens, printing inks, paints, ointments and creams because their characteristic structure possesses a physical and chemical stability, nontoxic property and low cost. Extensive efforts have been made to the research of 1-dimensional (1-D) nanomaterials and composite nanofibers based on ZnO nanoparticles, which have applied to various promising areas in categories of ‘photocatalysis’ and ‘antibacterial activity’.

In this work, to rise the photocatalytic and antibacterial properties, ZnO morphology control, preparation of PAN-ZnO composite nanofiber membranes were performed. Firstly, to enhance photocatalytic performance of ZnO, the 1-D ZnO nanomaterials were synthesized through a sol-gel process by adding various amounts of water. The morphology and structure of the 1-D ZnO nanostructures were characterized by XRD and TEM, and the optical property of ones was characterized by UV-vis spectroscopy and photoluminescence measurements. When the photocatalytic efficiency of the 1-D ZnO nanostructures was estimated for the degradation of methylene blue dye under irradiation of UV light (400 W), the photocatalytic kinetic constant increased from 0.067 min-1 to 0.481 min-1. As a result, the longer ZnO nanorods showed better photocatalytic performance.

To maximize antibacterial activity, ZnO/PAN composite nanofiber, which has a high surface-to-volume ratio and porosity that increase antibacterial activity. Polyacrylonitrile solutions with different ZnO nanoparticle concentrations (0, 10, 20, 30 %) were prepared by electrospinning technique. The prepared composite nanofibers were characterized by SEM, EDS and FT-IR, which confirmed that the morphology of the ZnO/PAN nanofibers and that the ZnO nanoparticles are well dispersed on the nanofiber surface. Antibacterial activity test of ZnO/PAN nanofibers were measured with Escherichia coli (ATCC 25922) bacteria strain. The result indicated that the ZnO 30 % nanoparticles incorporated in PAN nanofiber has excellent antibacterial activity compared with ZnO 0 %, ZnO 10 %, and ZnO 20 % ones.