Preparation, Structural Analysis, and Assessing the Impacts of Holmium and Ytterbium on Electrochemical Hydrogen Storage Property of Strontium Cerium Molybdate Nanostructures

Abstract

The global energy, political situation, and energy consumption today are different from that in the early 1970s. Understanding energy use is correlative with the environmental and human health concerns; therefore, other alternative fuels for everyday use are urgently required. Hydrogen, also known as a secondary energy source, is a promising alternative and clean burning fuel; however, it has a low energy per unit volume (low density), therefore requires an advanced storage method. Herein, we utilize an effective method (Pechini) for synthesis of SrCe_2-x-y(MoO₄)₄:xHo/yYb (x = 0, 0.1, y = 0, 0.3, 0.4) nanoparticles, in order to examine the electrochemical hydrogen storage properties of the samples. Prior to dive into this application, the analyzing based-composition, purity, and morphology of the samples confirm the formation of nanoscaled-SrCe_2-x-y(MoO₄)₄:xHo/yYb. The presence of metal–metal (M–M) bonds and M–O–M bonds affirm the complete interactions between precursors. Finally, the electrochemical hydrogen storage profiles of the samples containing Holmium (Ho) and Ytterbium (Yb), in 6M KOH electrolyte, indicate higher discharge capacities and charge-discharge efficiencies. In addition, as compared to the blank (the sample without Yb and Ho), the SrCe_1.6(MoO₄)₄:Ho_0.1/Yb_0.3 nanoparticles show an improved electrochemical hydrogen storage properties with the maximum discharge capacity of 3250 mAh g⁻¹ and discharge/charge efficiency of ~60% at 1 mA current.