Microstructure and electrochemical hydrogen storage properties of LaFe_1-xCo_xO₃ solid solutions

LaFeO₃-based materials have potential applications in the field of electrochemical hydrogen storage, due to their high-temperature stability, lower cost and excellent corrosion resistance. However, there are still drawbacks should be solved, such as the limited capacities and the restricted kinetic properties. To solve these issues, current researches usually choose the ways of doping to decorate the microstructure of the oxides and refined the particle sized to obtain higher surface areas, which are beneficial to enhance the hydrogen storage properties. In this paper, nanosized LaFe_1-xCo_xO₃(x = 0, 0.04, 0.12, 0.20, 0.28, 0.36) composite materials were synthesized via the sol-gel method. Microscopic characterization (XRD, SEM and TEM) results revealed that the crystallite sizes and cell volumes of the doped samples were decreased gradually with increasing the doped contents, and the doped Co³⁺ ions alleviated the agglomeration degree of the particles. Spectra analysis (UV–vis, Raman and FT-IR) manifested that doping ion induced the red shift of the band gap energies, the vibrations of Fe-O bond and increased the concentration of oxygen vacancies. The electrochemical properties research confirmed that the Co³⁺ ions doped samples possessed outstanding better hydrogen storage performances than those of the pure LaFeO₃. The maximum discharge capacities of Co_0.12 sample reached to 413.5 mAh·g⁻¹ at 333K, which is much higher than the pure LaFeO₃ (154.5 mAh·g⁻¹). Meanwhile, the kinetic properties of the doped samples were also significantly enhanced. The electrochemical hydrogen storage performances of LaFeO₃-based materials are closely related to the doped content, concentration of oxygen vacancies and the crystallite sizes of the samples. © 2025 Elsevier Ltd and Techna Group S.r.l.