<i>Marrubium vulgare</i> Leaves as a Biosorbent and Reducing Agent for the Green Synthesis of ZnO and Ag/ZnO: Towards an Efficient Treatment of Colored Wastewater

Abstract

The search for a cost-effective and environmentally friendly method of wastewater treatment is a global challenge. This is why, in this work, we have studied the removal of pollutants from wastewater using nanoparticles of zinc oxide, silver, and silver doped on zinc (Ag/ZnO, 20/80) synthesized from extracts of Marrubium vulgare leaves. IR, UV-visible and XRD characterizations show the formation of these nanoparticles. We then used the synthesized products for the degradation of an aqueous solution of crystal violet (15 ppm). The results obtained show that the adsorption efficiency of the crystal violet increases over time up to 97.88% for 0.3 g of M. vulgare leaf powder. The efficiency of photodegradation of the dye in the presence of ZnO, AgO, and Ag doped on ZnO increases over time until reaching 77.27% for 0.3 g of ZnO, 98.14% for 0.2 g of AgO, and 98.26% for 0.3 g of Ag/ZnO (20/80). The use of this composite aims to reduce the required amount of expensive silver and to increase the degradation effectiveness. Finally, we tested the nanoparticles in the treatment of synthetic dye wastewater.