Enhanced electrochemical hydrogen storage performance of titanate-based nanostructures synthesized by facile auto-combustion: Li2TiO3 nanostructures versus LaTiO3 nanoperovskites

Abstract

Green energies are vital for near-future energy needs. Hydrogen is a promising secondary energy career that counted as a clean-burning fuel. However, hydrogen suffers from a low volumetric energy density at ambient temperature and pressure. This deficiency has been overcome by “solid-state hydrogen storage” technologies, where the hydrogen is adsorbed/absorbed - depending on the type of materials - on a solid surface. Mixed metal oxides (MMOs) particularly transition-based metal oxides have been recently developed for hydrogen adsorption with a superior affinity for hydrogen. Here, we demonstrated two nanosized-MMOs based on (mono-) perovskite structure, Li2TiO3, and LaTiO3. These two MMOs are successfully synthesized via the auto-combustion method in the presence of starch fuel. After confirmation of their structures and morphologies, the samples are used for electrochemical hydrogen storage in an alkaline medium. The average particle diameters of Li2TiO3 and LaTiO3 are calculated to be around 16.74 and 24.46 nm, respectively. The results indicate a higher discharge capacity of LaTiO3 nanoperovskites (1140 mAh/g) as compared to Li2TiO3 nanoparticles (680 mAh/g); as confirmed primarily by cyclic voltammetry (CV), with the theoretical hydrogen capacities of 4.1% and 2.4%, respectively. We believe that novel MMOs can be potentially fulfilled the requirements of future energy targets, arranged and reported by US-department of energy (DOE).