Microwave-assisted one-pot preparation of AgBr/ZnO nanocomposites as highly efficient visible-light photocatalyst for inactivation of Escherichia coli

作者：Siyahi Vahide; Habibi Yangjeh Aziz^*; Latifi Navid Saeid; Asadi Asadollah

来源：Materials Express, 2015, 5(3): 201-210.

DOI：10.1166/mex.2015.1230

• Photocatalytic Inactivation
• E. coli
• Nanocomposite
• AgBr/ZnO
• Microwave

Microwave irradiation was applied for preparation of AgBr/ZnO nanocomposites by one-pot method at 5 min. The prepared nanocomposites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive analysis of X-rays (EDX) and UV-Vis. diffuse reflectance spectra (DRS) techniques. Photocatalytic inactivation of Escherichia coli (E. coli) was investigated on the nanocomposites under visible-light irradiation. Among the prepared nanocomposites, the sample with 0.237 mole fraction of AgBr exhibits the highest activity. The inactivation rate constant on the nancomposite is about 2.3 and 1.9-fold greater than for the ZnO and AgBr nanoparticles, respectively. The inactivation rate constant increases with weight of the photocatalyst up to 0.5 g/L and then decreases. Moreover, the rate constant increases with pH of solution up to 8.4 and then decreases. Influence of various scavengers demonstrates that holes play a vital role in achieving well inactivation of E. coli. In addition, no remarkable bacterial colony can be detected within 96 h after the inactivation which reveals that the photocatalytic inactivation leads to almost an irreversible damage of the bacteria. Finally, the photocatalyst retains more that 70% of its activity after seven cycles.

• 出版日期2015-6