Rapid photodecolorization of methyl orange and rhodamine B using zinc oxide nanoparticles mediated by pullulan at different calcination conditions

Abstract

Water is one of the humanity’s major resources, but it is actually at risk due to growth and urbanization. Water reclamation and reuse was introduced as one of the solutions. However, the presence of organic pollutants, such as dyes, in the reclaim water can cause adverse effect to human. The dyes can be removed through photocatalysis process where semiconductor materials such as zinc oxide (ZnO) is used as the catalyst. In this research, several zinc oxide nanoparticles (ZnO NPs) were developed with pullulan as the capping agent through green synthesis. The impact of calcination conditions on the properties of synthesized ZnO NPs was explored. All the synthesized samples were subjected to photocatalytic degradation of two dyes, methyl orange (MO) and rhodamine B (RhB). The results indicated that with the increment of calcination temperature, the average particles size increased from 28.86 to 127.69 nm and the surface area reduced from 30.7996 to 12.3757 m2 g−1. As the calcination time changed, substantial impact was observed where, as calcination time increased to 2 h, the average particles size and the surface area significantly increased and reduced, respectively. The best photocatalytic degradation of MO and RhB was observed using ZnO NPs produced at 400 °C and 1 h calcination conditions. Overall, ZnO NPs have a good prospect to be applied for removal of dyes in wastewater.