Publication: Development of piezo-assisted zinc oxide-based photocatalysts grown by direct heating method
Date
2024-08-01
Authors
Lai Yue Cheng
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Abstract
Industrial development and population growth have increased waste generation, stressing water resources. ZnO is widely used in photodegradation for wastewater treatment due to its unique properties. However, ZnO possess limitations in efficiently utilizing visible light and exhibits inefficiencies in the absence of light. It exhibits rapid recombination of charge carrier, hindering their sustained and effective use. This affects the overall photocatalysis performance of ZnO. This project utilized the DH method to investigate the effect of synthesis duration on ZnO rods grown on kanthal meshes. Following this, an Au layer was sputtered onto the pre-grown ZnO nanorods and the piezo-assisted ZnO-based photocatalyst was examined for MB removal under different light sources and stirring conditions. The synthesized samples were characterized by XRD, FESEM, XPS, Raman, RTPL and UV-visible spectroscopy. The average length and diameter of the optimized ZnO rods were 1.847 μm and 0.292 μm, respectively. The average photocurrent measured by Au/ZnO was 1.977 mA under UV light, 1.6 mA under visible light, and 1.201 mA in dark conditions with stirring. These findings were correlated with the removal of MB dye, i.e. under UV light, visible light, and in dark conditions with stirring. The higher photocatalytic performance of Au/ZnO in visible light was attributed to the LSPR of the Au which facilitated efficient charge carrier transport and suppressing recombination of electrons and holes. In conclusion, Au/ZnO/kanthal mesh composites demonstrated positive performance to degrade MB dye under illumination of UV light, visible light, and in dark conditions, especially in the presence of stirring.