Pb–Pb Raman Modes in Amorphous Lead Nanostructures in Zeolite X

Abstract

Abstract Amorphous lead nanostructures have been obtained by ionic interchange and reduction in faujasite zeolite X (F9) matrix. The size and amorphous nature of the lead nanostructures was determined by transmission electron microscopy and the chemical composition by energy-dispersive X-ray spectroscopy measurements. The Raman spectrum of the lead species in the zeolite X displays a peak at 112 cm−1 which has been assigned to Pb–Pb vibration modes in the amorphous nanostructures. The structure and vibrational properties of Pbn clusters, for n = 2 to 20, were determined using Hartree–Fock and density functional theory. The optimized Pbn structures present a vibration mode at a frequency around that observed in the Raman spectrum of the amorphous lead nanostructures.