Fatigue free relaxor ferroelectric and electrocatalytic hydrogen evolution of yttrium substituted BaBi2Nb2O9 layered structured nanoceramics for energy storage application

Lead-free bismuth layered structured ferroelectric ceramics are highly important in superior energy storage applications. The slim hysteresis curve with high energy storage density and efficiency is expected for wide application. In this regard, the suitable electrocatalyst for the generation of hydrogen gas through water-splitting show high importance as an alternative energy source. The current article aims to investigate the above goals by incorporating 5% yttrium at the place of bismuth for BaBi2Nb2O9 relaxor ferroelectrics. The solid-state synthesized method successfully prepared the single-phase material and is confirmed through spectroscopic and morphological analysis. The dielectric characteristics follow diffused phase transition with broad temperature dependence that indicated the space charge polarization in the material owing to the presence of Y3+ at different domains. The higher degree of diffuseness and low dielectric loss implies the significant role of charge carriers during frequency and temperature variation in the dielectric study. Impedance spectroscopy analysis indicates the non-Debye type relaxation and NTCR behavior of the material that is correlated to the multiple relaxation processes. The slim P-E hysteresis curve and fatigue-free properties of the materials up to 106 cycles reflect its usefulness in the potential device as NVRAM applications. The materials are also used for hydrogen evolution reaction (HER) under an electrochemical condition. A lower overpotential value of 180 mV is obtained at 10 mA cm(-2) current density. The lower Tafel slope and charge transfer resistance value support its superior HER activity. The above results demonstrated the potential application of the studied material (BaBi1 center dot 9Y0 center dot 1Nb2O9) in the energy storage application and as an electrocatalyst for alternative energy source.