Doru C. Lupascu

The investigation delves into the functionality exhibited by ferroelectric BiFe 0.95 Mn 0.05 O 3 (BFM) nanoparticles (NPs) concerning the hydrogen evolution reaction (HER). The electrocatalytic activity of BFM NPs undergoes a transformative shift as a consequence of mono‐, di‐, and tri‐valent cation substitution. Notably, the strategic engineering of doping at the Bi site within BFM NPs yields a remarkable outcome, namely the conspicuous reduction of the kinetic overpotential prerequisite for HER. This diminished overpotential in doped BFM NPs arises from the confluence of multifarious factors: diminished charge transfer resistance, augmented specific surface area, a discernible distribution of pore sizes ranging from narrow to broad, particles endowed with a shape boasting abundant active facets, and the integration of dopants as novel active sites on the surface. Furthermore, the presence of surface defects, oxygen vacancies, and amplified microstrain within doped BFM NPs contributes to the reduction in overpotential.