<i>Eichhornia Crassipes</i> Plant Extract Templated Green Synthesis of Cr <sub>2</sub>O <sub>3</sub>/ZnO Composite Catalyst for the Degradation of Organic Dye

Abstract

Water hyacinth (Eichhornia Crassipes) plant extract mediated ZnO, Cr2O3, and Cr2O3/ZnO composite catalysts with the addition of different amount of Cr precursor abbreviated as 0.1CrZn, 0.08CrZn, 0.06CrZn, 0.04CrZn and 0.02CrZn at fixed Zn content (0.1 molar) were synthesized by green co-precipitation routes. The resulting samples were characterized and tested for MB dye degradation under visible light irradiation. The catalytic degradation of MB dye by 0.08CrZn catalyst was achieved 85% within 90 min irradiation time. However, in the presence of 0.1CrZ, 0.062CrZ, 0.04CrZ, 0.02Cr, ZnO, and CrO3 catalysts, degrades only 80, 74, 79, 76, 52, and 74% of MB dye, respectively. The results indicated that the addition of optimum amount of Cr in the preparation of Cr2O3/ZnO composite catalysts with the aid of Eichhornia crassipes plant extract enhances the catalytic activities. This could be due to lowering the electron and hole separation and the porosity resulted from the plant extract in the catalyst system.