Electrocatalytic HER and magnetism performance of BiMnO3 modified BaTiO3 – A ultra high dielectric constant ceramic nanomaterial

Abstract

High dielectric constant with green hydrogen gas productivity holds promising characteristics for futuristic advanced functional materials. Ultrahigh dielectric constant covering BiMnO3 modified BaTiO3 (0.5BaTiO3-0.5BiMnO3, abbreviated as BTBiM5) was chemically furnished through the precursor solution decomposition method. The spherical morphological nanocrystalline ceramics contain a tetragonal phase with 32 nm crystallite size. The cationic size alteration and temperature dealing creates oxygen vacancies which are reflected in powder X-ray diffraction (XRD) pattern shifting and the presence of lower oxidation states of Bi and Mn. The BTBiM5 sintered pellet demonstrates ultrahigh dielectric constant (108 order) at low frequencies (1 kHz). The relaxor-diffusive nature of BTBiM5 is identified with 1.37 diffusivity. The single semicircular Nyquist plot corresponds to non-Debye type characterizations with a grain conductivity nature. The room temperature magnetism performance finds saturation of magnetization of BTBiM5 after 200 Oe. The nanocrystalline BTBiM5 is functionalized as an electrocatalyst to produce green hydrogen gas under alkaline conditions. In this regard, 223 mV overpotential at 30 mA cm−2 current density is recorded with 152 mV dec−1 Tafel slope. The six-hour chronoamperometry test identifies the durability of the material during the electrocatalytic process that confers the probable grant massive footprint of such type of materials in the near future.