Helianthus annuus assisted green synthesis of Co₃O₄ and Ag-Co₃O₄ and evaluation of their catalytic activities toward photodegradation of crystal violet dye

Nowadays, plants assisted green synthesis of metal oxide nanoparticles attracted the interest of researchers due to economic and environmental points of view. This article reports the Helianthus annuus (sunflower) leaves assisted green synthesis of Co₃O₄ and Ag-Co₃O₄ particles. In this method, the leaves extract of Helianthus annuus (sunflower) is utilized as a reducing and stabilizing agent for the synthesis of Co₃O₄ and Ag-Co₃O₄ particles. XRD and FTIR confirmed the crystalline and spinel phase of prepared Co₃O₄ and Ag-Co₃O₄ particles. The catalytic activities of prepared particles were evaluated over the photodegradation of crystal violet dye under visible irradiation. About 63% and 98% of 100 mg/L degraded over 0.002 g/ml of Co₃O₄ and Ag-Co₃O_4, respectively. The reaction kinetics and mechanism were described in terms of the Eley-Rideal mechanism. The rate constant was determined as 0.0075 and 0.0167 per minute for Co₃O₄ and Ag-Co₃O_4, respectively.