Crucial roles of structural, morphological, and optical properties in enhancing the photocatalytic performance of ZnO nanorods

ZnO nanorods with different structural, morphological, and optical properties were fabricated using hydrothermal process by controlling hydrothermal reaction temperature. It has been presented that the structural, morphological and optical properties of the nanorods are strongly influenced by the hydrothermal reaction temperature. XRD results show that ZnO nanorods have a polycrystalline structure with hexagonal wurtzite. Increasing hydrothermal reaction temperature up to 100 degrees C stimulates the vertically standing growth along the c-axis orientation on the substrate as shown in FESEM images. The growth is followed by the decrease of the transmittance and energy band-gap of the ZnO nanorods. The photocatalytic activity of ZnO nanorod was evaluated using the percentage degradation of Coomassie (R) Brilliant blue and Indigo carmine dyes as a function of irradiation time. The photodegradation efficiency of ZnO nanorods synthesized with hydrothermal reaction temperatures at 80, 90 and 100 degrees C for decolorization of Coomassie (R) Brilliant blue was 71%, 75% and 81%, respectively, while for Indigo carmine was 50%, 53% and 66%, respectively. The variations of efficiency values indicate that the structural, morphological, and optical properties of ZnO nanorods play an important role in photocatalytic activity.