Synthesis and Applications of ZnO Nanorods

Abstract

Small-diameter ZnO nanorods have been prepared from aqueous solution containing Zn(OH)4 2− ions, manganese acetate, and sodium dodecyl sulfate in 3 h at room temperature. The added Mn2+ ions are considered to lead to the formation of MnO2 nanoparticles, which serve as the nucleation sites, to facilitate the growth of small diameter ZnO nanorods. The as-prepared ZnO nanorods are single crystalline, 7–10 nm diameter and 200–300 nm in length. The high surface-to-volume ratios determined by the Brunauer–Emmett–Teller method and the surface oxygen deficiencies suggested by the cathodoluminescence spectrum for the ZnO nanorods are conductive to the photocatalytic activity. The photocatalytic activities on the conversion of nitride oxides and degradation of methylene blue by ZnO nanorods were found to be significantly enhanced by the presence of small-diameter ZnO nanorods. Different sizes of ZnO nanorods were mixed with TiO2 nanoparticles with a 1:99 ratio to prepare thin film for dye-sensitized solar cells. The cell efficiency was measured and the optimal condition in our experiments was found. The Voc and FF were found to increase with the decrease of sizes of ZnO nanorods added. The capacitance and transient photocurrent data show correlations to the tendency of short-circuit current (Jsc). Thus, simulation model have been constructed to explain this phenomenon. The contacts between TiO2 nanoparticles and ZnO nanorods are crucial to the electrical properties. This calculation may have potential in finding best sizes of ZnO nanowires and TiO2 nanoparticles in TiO2/ZnO nanoparticle/nanorod composite film for DSSC.