Photodegradation of methylene blue in water and antibacterial Property of Cu-doped ZnO/rice husk ash composite

• Main Authors: Millora, Bianca Ysabel, Cacho, Carla Mae
• Format: text
• Language: English
• Published: Animo Repository 2023
• Subjects: Rice hulls; Ash disposal; Zinc oxide; Biochemistry, Biophysics, and Structural Biology
• Online Access: https://animorepository.dlsu.edu.ph/etdb_chem/30; https://animorepository.dlsu.edu.ph/context/etdb_chem/article/1036/viewcontent/2023_Millora_Cacho_Photodegradation_of_Methylene_Blue_in_Water_Fulltext.pdf
• Institution: De La Salle University

Rice husk is one the largest contributors of agricultural wastes due to the lack of proper disposal. Moreover, its derivatives such as rice husk ash (RHA) also pose the same problem as well as a potential health hazard and pollutant. RHA contains silica, which can be used as a component of photocatalysts to increase the surface area of active sites. In this study, RHA was utilized to synthesize a composite with zinc oxide (ZnO) as the base photocatalyst to help reduce the impact of RHA waste. In addition, the antibacterial properties of ZnO and copper-doped catalysts were also investigated. Four photocatalysts were synthesized, ZnO, ZnO/RHA with weight ratios of 0.65 and 0.8, and a copper-doped ZnO/RHA catalyst. The resulting catalysts were subjected to FTIR and SEM-EDX analysis, where the morphology, structure, and composition of the synthesized photocatalysts were determined. Photodegradation activities against methylene blue (MB) as the model organic pollutant (MOP) were executed, followed by an antibacterial assay against E.coli and S.aureus, where it was found that ZnO was the most effective against E.coli, and the Cu-doped ZnO/RHA was the most effective against S.aureus. The addition of RHA to ZnO resulted in better degradation efficiency, yielding 58.15% and 51.81% for ZnO/RHA with weight ratios of 0.65 and 0.8 respectively. While ZnO, in comparison, had the lowest degradation efficiency at 27.25% at the end of the 1-hour photodegradation activity.