Facile functionalization of Fe_2O_3 nanoparticles to induce inherent photoluminescence and excellent photocatalytic activity

摘要

Herein, we report the emergence of intrinsic multicolor photoluminescence in Fe_2O_3 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 Fe_2O_3 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 Fe~(3+)of the NPs and d-d transitions centered over Fe~(3+) ions in the NPs play the key role in the emergence of multiple photoluminescence from the ligand functionalized Fe_2O_3 NPs. Moreover, vibrating sample magnetometry measurements demonstrate that the surface modification changes the magnetic behaviour of Fe_2O_3 NPs upon functionalization. We believe that the great potential of our versatile, ferromagnetic, multicolor photoluminescent Fe_2O_3 NPs would stimulate the development of numerous opportunities toward their biological and technological applications.