Magnetic and optical investigation of Eumelanin-ZnO as organic-non-organic nanocomposite

Abstract Considerable interest has been devoted to zinc oxide (ZnO) based organic nanocomposites due to their exceptional properties. In this work, we investigated the structural, morphology, optical, and magnetic properties of ZnO nanoparticles doped with natural eumelanin (ZnO-Mel). The structural properties showed that the ZnO and ZnO-Mel nanocomposites have a wurtzite structure, and no secondary phase was detected, indicating that the doped natural eumelanin atoms are located within the ZnO host lattice. UV–vis measurements revealed that the band gap of ZnO increased upon incorporation of natural eumelanin. This study demonstrated that the ferromagnetic behavior of ZnO nanoparticles is a result of the incorporation of functional groups of natural eumelanin into the ZnO lattice, which changed only the properties of ZnO without changing its structure, as shown clearly by the XRD results. Changes in the properties of zinc oxide by the natural organic material eumelanin opens new horizons in organic-inorganic nanocomposites, which is a current challenge, and new applications in devices such as spintronic devices.