부산대학교 도서관

The objectives of this study were twofold: firstly, to study the morphology and particle size of ZnO as a function of [Zn(Ac)]/[KOH] ratios, and secondly, to research the effect of morphological properties on the photocatalytic degradation of Rhodamine B (RhB) dye. ZnO particles were synthesized by hydrothermal method. They were characterized by XRD, FTIR, SEM, TEM, SEM-EDS, XPS, UV–Vis, and Zeta potential techniques to study crystalline structure applying Rietveld refinement method, vibrational transitions, morphology, elemental analysis, chemical state of the elements on the surface, optical properties, and suspension stability of particles, respectively. XRD, FTIR, and XPS confirmed the preparation of pure ZnO particles without impurities. SEM and TEM study revealed morphologies of hexagonal prisms, platelets, and thin hexagonal prism rods; the elemental analysis shows a stoichiometric atomic ratio to Zn:O close to 1. Particle size decreases drastically when KOH quantity content increases in the precursor dissolution; it decreases systematically from ∼5600 nm to 200 nm. UV–Vis showed band gaps of 3.17–3.24 eV, and Zeta potential was from −23 to 9 mV. Crystallographic faces in ZnO monocrystal particles affected the photocatalytic reaction towards RhB degradation, while no photolytic or adsorbent effect was observed. The photocatalytic evaluation revealed that elongated particles with hexagonal rod morphologies (r(002)/(100) = 0.76, width = 156 ± 49 nm, and length = 1281 ± 423 nm) demonstrated high degradation of RhB (87% after 80 min of reaction), with kinetic parameters of k = 2.32 × 10−2 min−1 and t(1/2) = 4.5 min. The particles showed adequate reusability and the same performance.