Al-Ce co-doped BaTiO₃ nanofibers as a high-performance bifunctional electrochemical supercapacitor and water-splitting electrocatalyst

Supercapacitors and water splitting cells have recently played a key role in offering green energy through converting renewable sources into electricity. Perovskite-type electrocatalysts such as BaTiO₃, have been well-known for their ability to efficiently split water and serve as supercapacitors due to their high electrocatalytic activity. In this study, BaTiO₃, Al-doped BaTiO₃, Ce-doped BaTiO₃, and Al-Ce co-doped BaTiO₃ nanofibers were fabricated via a two-step hydrothermal method, which were then characterized and compared for their electrocatalytic performance. Based on the obtained results, Al-Ce co-doped BaTiO₃ electrode exhibited a high capacitance of 224.18 Fg⁻¹ at a scan rate of 10 mVs⁻¹, high durability during over the 1000 CV cycles and 2000 charge–discharge cycles, proving effective energy storage properties. Additionally, the onset potentials for OER and HER processes were 11 and − 174 mV vs. RHE, respectively, demonstrating the high activity of the Al-Ce co-doped BaTiO₃ electrode. Moreover, in overall water splitting, the amount of the overpotential was 0.820 mV at 10 mAcm⁻², which confirmed the excellent efficiency of the electrode. Hence, the remarkable electrocatalytic performance of the Al-Ce co-doped BaTiO₃ electrode make it a promising candidate for renewable energy technologies owing to its high conductivity and fast charge transfer.