In this study, zinc vanadate nanostructures with different morphologies, including nanoribbons and hollow spheres, were synthesized for the first time using a hydrothermal method and used for hydrogen storage. The width of the nanoribbons was controlled by using ammonia as the hydroxide ion generation agent. Sucrose was employed as a template to provide a suitable environment for the accumulation and reaction of zinc and vanadium ions during the hydrothermal process. To create hollow spheres, the synthesized materials were calcined and characterized using XRD, FT-IR, EDS, and FESEM analyses. XRD results revealed that different zinc vanadate compounds were formed depending on the ammonia content. FESEM and TEM investigations confirmed the formation of hollow spheres after the removal of the sucrose template at high temperature. The electrochemical hydrogen storage performance of different zinc vanadate samples (H1, CH1, CH2, and CH6) was investigated using chronopotentiometry in 6.0 M KOH solution. Sample H1 (Zn2(OH)(VO4)) showed a discharge capacity increase from 8 mAh/g to 218 mAh/g from the first to the 15th cycle, while CH1 (Zn2V2O7) exhibited an improvement from 64 mAh/g to 463 mAh/g. Sample CH2, also composed of Zn2V2O7 but with a rod-like morphology, demonstrated discharge capacities of 78 mAh/g and 648 mAh/g for the first and 15th cycles, respectively. Notably, sample CH6 (Zn2V2O7/Zn4V2O9), comprised of hollow spheres, displayed a significant discharge capacity increase from 92 mAh/g to 1027 mAh/g over 15 cycles, outperforming other samples. This superior performance of CH6 is attributed to its unique hollow sphere architecture, which facilitates electrolyte penetration and electron transport, a high specific surface area that accelerates H+ diffusion, and the synergistic effect of Zn4V2O9 and Zn2V2O7 enhancing electrocatalytic properties and conductivity.
