Structural, morphological, and optical investigation of PbTiO₃ doped BiFeO₃ Nanoparticles derived from sol-gel method

Abstract Bismuth ferrite (BF) exhibits excellent multiferroic properties at room temperature, making it a promising candidate for energy storage devices. Over the past few years, bismuth ferrite nanoparticles (BFNP) have gained significant attention due to their potential applications. The main goal of this study is to make pure, single-phase PbTiO 3 (PT)-doped BiFeO 3 (BF-xPT, x = 0.2 and 0.4) powders using the sol–gel method (with sizes ranging from 40 nm to 1.6 μm). PbTiO 3 doping helps to reduce the crystallographic defects in BiFeO 3 , leading to its improved structural stability and better control over particle size. The structural, morphological, and optical properties of the BFNP were investigated using high-resolution x-ray diffraction (HR-XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), energy dispersive x-ray (EDX) analysis, UV-visible spectroscopy, and photoluminescence (PL) spectroscopy. A significant change in the crystallographic structure from tetragonal to monoclinic was observed. The particle size distribution was quantified using TEM, revealing average nanoparticle sizes of 110 ± 35 nm for BF-0.2PT and 79 ± 15 nm for BF-0.4PT. The bulk samples of BF-0.2PT and BF-0.4PT measure around 1.6 μm and 350 nm, respectively. Additionally, the optical band gaps (OBG) of these nanoparticles were found to be tunable between 2.18 and 2.62 eV, depending on the particle size and doping concentration. The tunability of the OBG in BF-xPT nanoparticles makes them promising candidates for solar cell applications, energy storage devices such as supercapacitors, and many more. The broader impact of this work lies in its potential to advance the development of efficient, sustainable materials, contributing to the progress of clean energy technologies and paving the way for more effective solutions in renewable energy, energy conversion, and optoelectronic industries.