Synthesis and characterization of ZnO/CeO2/SiO2 nanostructures by sol-gel method for electrochemical hydrogen storage

In this study, SiO2, CeO2/SiO2, ZnO/SiO2, and ZnO/CeO2/SiO2 nanostructures were synthesized by sol-gel method in two ways using TEOS, cerium nitrate, and zinc nitrate as precursors. In the first method, salts were added at the end, but in the second method, TEOS was added at the end. With the difference in the order of adding materials, the distribution of materials in the composites and the size of the particles changed significantly. The best conditions in terms of material composition and particle size were for the ZnO/CeO2/SiO2 nanocomposite synthesized by the second method. EDS, FT-IR, FESEM, BET, and XRD analyzes were performed for the samples to confirm the formation of the expected nanostructure. Finally, the ZnO/CeO2/SiO2 nanocomposite synthesized by the second method was evaluated to determine the electrochemical hydrogen storage capacity. With the chronopotentiometric method, its hydrogen storage capacity was recorded as 708.75 mAh/g, which is a significant amount compared to the reported capacities. The comparison of this number with the storage capacity of silica and ceria nanostructures also shows the constructive effect of these materials on each other. According to the results, the second synthesis method is a more suitable method for making these nanomaterials for electrochemical hydrogen storage.