Nanostructural engineered titanium dioxide by rare earth metals dual doping for electrochemical supercapacitor applications

High-porosity nanostructured materials are in high demand for use in electrochemical supercapacitor applications due to their immense specific surface areas, which allow for significant energy storage capacity. Using Ti(CH₃COO)₂⋅2H₂O and nitrate salts of dopants such as Cerium, Samarium, Holmium, and Ytterbium as precursors, we synthesized mixed metal-doped TiO₂ nanostructures using a facile sol–gel approach. The Ce/Ho Co-doped TiO₂ nanostructures-based supercapacitor electrodes retained 99.28% of their capacity after 5,000 cycles, with a specific capacitance of 1714 F g⁻¹ at a current density of 2.0 A g⁻¹. The enhanced electrochemical performance of the optimized Co-doped TiO₂ nanostructures can be attributed to the increased TiO₂ conductivity due to the optimization of co-doping and the increased specific surface area as a result of structural porosity. These results suggest that porous co-doped TiO₂ nanostructures have a wide spectrum of potential electrochemical applications.