Islands of CdSe nanoparticles within Se nanofibers: a room temperature ionic liquid templated synthesis

Abstract

Herein, we present the formation of cadmium selenide (CdSe) islands embedded in a porous structure of entangled selenium (Se) nanofibers in the host matrix of a room temperature ionic liquid (RTIL). Electron beam irradiation has been employed to initiate the formation of the nanostructure while RTIL simultaneously played the role of a solvent, stabilizer and a shape guiding template for such morphology. UV-Vis absorption spectra of the irradiated samples exhibited an excitonic absorption feature in the visible region. The as-obtained nanostructure was characterized by TEM, SEM, XRD and EDX studies. Raman spectroscopic analysis of as-grown nanomaterials provided significant information about the formation of CdSe as well as distinct features of different forms of Se which further substantiated the results obtained from the above mentioned studies. Interestingly, an equivalent dose of γ-radiation led to the formation of predominantly nanosheet like structures in conjunction with a relatively homogeneous distribution of CdSe nanoparticles in the same matrix. The possible mechanism behind the obtained structures in these two methods has been proposed, and was rationalized in terms of dose rate difference and the existence of inherent heterogeneity in the structure of the IL. Finally, the implications of such a structure in various fields such as catalysis, sensing and photovoltaics have been discussed.