Exploiting multiferroicity of TbFeO₃ nanoparticles for hydrogen generation through photo/electro/photoelectro-catalytic water splitting

Hydrogen is a potential future energy source that could replace conventional fuel and provide the necessary energy. Multiferroic materials are the most likely choices for water splitting due to their ferroelectric characteristics and ability to function as magnetically recoverable catalysts. Multiferroic terbium orthoferrite nanoparticles were synthesized at low temperature by the polymeric citrate precursor route to study the photocatalytic, electrocatalytic and photoelectrochemical activity towards hydrogen production. Powder X-ray diffraction revealed successful formation of orthorhombic TbFeO₃ nanoparticles. A larger aspect ratio of 3.9 and a bandgap of 2.13 eV were seen in the elongated TbFeO₃ nanoparticles, which contributes to the photo/electro-catalytic activity. Magnetic and ferroelectric studies revealed weak ferromagnetism and ferroelectric polarization of 0.037 μC cm⁻² in TbFeO₃ nanoparticles, confirming multiferroicity. Visibly active and multiferroic TbFeO₃ nanoparticles showed notable hydrogen evolution of 1.44 mmol h⁻¹ g⁻¹. In electrocatalytic and photoelectrochemical water splitting investigations, TbFeO₃ nanoparticles demonstrated current densities of 30 and 60 mA cm⁻², respectively. EIS, TRPL, transient photocurrent and Mott-schottky measurements were used to examine charge transfer kinetics. The high H₂ evolution and good OER/HER tests were attributed to increased charger separation efficiency due to ferroelectricity induced band bending.