Tecoma stans floral extract-mediated synthesis of MgFe2O4/ZnO nanoparticles for adsorption and photocatalytic degradation of coomassie brilliant blue dye

Toxic organic dyes-containing wastewater treatment by adsorption and photocatalytic techniques is widely applied, but adsorbents and photocatalysts are often synthesized through chemical methods, leading to secondary pollution by released chemicals. Here, we report a benign method using Tecoma stans floral extract to produce MgFe2O4/ZnO (MGFOZ) nanoparticles for adsorption and photocatalytic degradation of coomassie brilliant blue (CBB) dye. Green MGFOZ owned a surface area of 9.65 m2/g and an average grain size of 54 nm. This bio-based nanomaterial showed higher removal percentage and better recyclability (up to five cycles) than green MgFe2O4 and ZnO nanoparticles. CBB adsorption by MGFOZ was examined by kinetic and isotherm models with better fittings of Bangham and Langmuir or Temkin. RSM-based optimization was conducted to reach an actual adsorption capacity of 147.68 mg/g. Moreover, MGFOZ/visible light system showed a degradation efficiency of 89