Green synthesis and characterization of CdO nanoparticles from Crocus sativus: A promising material for hydrogen gas storage

Abstract

This study aims to environmentally synthesize and fully characterize CdO nanoparticles by utilizing an eco-friendly process that involves Crocus sativus in its reaction with cadmium ions. The CdO nanoparticles underwent characterization, and their purity was confirmed through XRD and UV-Vis spectroscopy. Additionally, scanning electron microscope and transmission electron microscopy revealed that the prepared cadmium oxide nanoparticles exhibited polymorphism, with diameters ranging between 42 and 67 nm. Furthermore, the Fourier transformation infrared spectroscopy showed the main bands of cadmium oxide at 1047, 542, and 1310 cm−1. Furthermore, the cadmium oxide nanoparticles were employed in a study focusing on gas storage, particularly hydrogen (H2) storage. The results of the hydrogen storage study demonstrate that the maximum H2 uptake reached 2.85 Wt.%H2 at a pressure of 69 bar at 77 K, with ∆H = 0.62607 KJ/mol H2 and ∆S = 3.35697 J/mol H2·K. Moreover, thermodynamic investigations at four different temperatures confirm that the maximum H2 uptake can be achieved within a pressure range of 69–86.2 bar.