Nanoparticle tracking analysis (NTA) for the size distribution of the NPs has been done using Nanosight 300 (Malvern panalytical) equipment. The 1:100 times diluted iron oxide NPs suspension was applied for the NTA analysis. For a schematic diagram of the green synthesis, the steps involved refer to Scheme 1. Diffuse reflectance mode UV absorption using (Lambda 1050, PerkinElmer) with UV vis resolution 0.05nm followed by Tauc analysis (equation no.4) gives the band gap of the material.