Facile functionalization of Fe2O3 nanoparticles to induce inherent photoluminescence and excellent photocatalytic activity

Abstract

Herein, we report the emergence of intrinsic multicolor photoluminescence in Fe2O3 nanoparticles (NPs) ranging from blue, cyan, to green, upon facile functionalization and further surface modification with a small organic ligand, Na-tartrate. Moreover, we have found unprecedented photocatalytic property of the functionalized Fe2O3 NPs in the degradation of a model water-contaminant. Meticulous investigation through UV-visible absorption and fluorescence study along with theoretical support from literature unfolds that ligand-to-metal charge-transfer transition from the tartrate ligand to the lowest unoccupied energy level of Fe3+ of the NPs and d−d transitions centered over Fe3+ ions in the NPs play the key role in the emergence of multiple photoluminescence from the ligand functionalized Fe2O3 NPs. Moreover, vibrating sample magnetometry measurements demonstrate that the surface modification changes the magnetic behaviour of Fe2O3 NPs upon functionalization. We believe that the great potential of our versatile, ferromagnetic, multicolor photoluminescent Fe2O3 NPs would stimulate the development of numerous opportunities toward their biological and technological applications.