Spinach Extract Derived Carbon Dots Decorated on ZnO Nanorods for Photocatalytic Dye Degradation

The carcinogenic and mutagenic nature of organic dyes makes their removal from dye-containing wastewaters essential prior to the discharge of such wastewaters. We synthesized carbon dots having emission wavelengths in the near-infrared region from spinach extract. Thereafter, CDs were embedded on ZnO nanorods through hydrothermal treatment. The prepared ZnO doped with CDs were characterized by various analytical instruments and used to photocatalytically degrade methylene blue dye under sunlight. The as-prepared ZnO exhibited nanorod morphology, with the CDs doped on its surface. The dye degradation followed pseudo-first-order kinetics; the ZnO doped with CDs synthesized at pH 10 achieved the highest dye degradation, with a kinetic coefficient of 0.02889 min −1 . This study shows that the photocatalytic efficiency of ZnO can be effectively improved by doping with CDs.