Effect of Preparation Technology of Nano-ZnO on Its Morphology and Photocatalytic Activity

Abstract

Using Zn(NO₃)₂•6H₂O and NaOH as raw materials, hydrothermal method was employed to prepare nano-ZnO by changing the proportion of materials and adding surfactant. The products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that at n(OH⁻):n(Zn²⁺) = 4:1, the nano-ZnO had a sheet-like structure with average thickness of 80 nm; at (OH⁻):n(Zn²⁺) = 10:1, nano-ZnO had a pencil-like structure with the diameter of 220 nm. Rhodamine was used as pollutant to carry out photocatalytic experiments. The results indicated that the photocatalytic performance of sheet-like ZnO was superior to that of pencil-like ZnO. As to the influence of different surfactants, the ZnO had a rod-like structure with the addition of dodecyltrimethylammonium bromide (DTAB), and its photocatalytic performance was enhanced. The photocatalytic performance of ZnO prepared with the addition of Sodium dodecylbenzenesulfonate (DBS) was also improved, though by a smaller extent compared with the addition of DTAB.

Keywords:

• Hydrothermal method
• nano-ZnO
• photocatalytic
• surfactant