ZnO Nanostructure Based Photocatalysis for Water Purification

Abstract

In recent years, semiconductor based photocatalysis has shown great potential for an application as a low-cost, environmentally friendly and sustainable water treatment technology. Its efficiency has been widely demonstrated on the removal of persistent organic compounds in water. This paper studies the photocatalytic activity of ZnO nanowires (NWs) grown on a substrate, a configuration which can be considered advantageous over freely suspended nanoparticles (NPs) commonly used in many research works, due to its easy removal from purified water and reutilization. The characterization of the ZnO NWs morphology and structure was performed by scanning electron microscope (SEM) and X-ray diffraction (XRD) measurements. The photocatalytic efficiency study has been carried out by using three organic dyes (MB, MO and AR14), as commonly used pollutants in various industrial activities. For a better understanding of the photocatalytic efficiency versus the liquid regime, the photocatalysis has been carried out under classic mode and microfluidic mode. All tests shown the notable photocatalytic efficiency of ZnO NWs. Moreover, remarkable results were achieved with our ZnO-NWs-integrated microfluidic reactor, which exhibited an important enhancement of photocatalytic activity by reducing the photodegradation time from hours to minutes.

TiO2-Coated ZnO Nanowire Arrays: A Photocatalyst with Enhanced Chemical Corrosion Resistance

“…UV-Vis spectroscopy was used to evaluate the photodegradation efficiency of the organic dye MB (Certistain ® , SigmaAldrich, Burlington, MA, USA), which is one of the most common pollutants in industrial wastewater [25], and the process of the photodegradation experiment was basically the same as in our previous research [26,27]. The evolution of the MB concentration has been assessed by absorption spectroscopy at 665 nm, corresponding to the strongest absorption peak.…”