Effect of pH on the green synthesis of ZnO nanoparticles using Sorghum bicolor seed extract and their application in photocatalytic dye degradation

Abstract

This work proposes the green synthesis of ZnO nanoparticles (NPs) using an aqueous extract of sorghum seed (Sorghum bicolor L. Moench). The effect of synthesis pH on the structural, morphological, and surface properties of ZnO NPs is investigated. The results revealed that pH influences crystallinity, surface-adsorbed functional groups, agglomeration, and nanoparticle size. ZnO NPs synthesized at pH 11 exhibited the best properties for complete photocatalytic degradation of methylene blue (MB) dye under sunlight in 40 min.