Preparation of flower-like ZnO hierarchical structures for photodegradation of phenol under UV irradiation

Abstract

This paper reports the synthesis of flower-like ZnO hierarchical structures via a simple and economical citric acid-mediated hydrothermal route. The as-synthesized flower-like ZnO was characterized in detail by field-emission scanning electron microscopy (FESEM), energy dispersive X-ray, transmission electron microscopy (TEM), X-ray diffraction (XRD), N2 adsorption–desorption, UV–visible absorption, Fourier-transform infrared (FTIR), and Raman analysis. FESEM and TEM showed that the flower-like ZnO was an assembly of large numbers of interleaving nanosheets of average thickness approximately 88 nm. XRD, FTIR, and Raman results showed that the as-synthesized ZnO products were highly crystalline with the wurtzite structure. Photocatalytic tests indicated that the as-synthesized flower-like ZnO had efficient photocatalytic activity in the degradation of phenol under UV irradiation. The degradation of phenol was further confirmed by the formation of intermediates, identified by use of high-performance liquid chromatography, and the decrease in the total organic carbon concentration. The flower-like ZnO was reused several times without appreciable loss of activity. These characteristics showed the flower-like ZnO hierarchical structure is suitable for practical applications in environmental remediation.