Facile co-precipitation synthesis of nano-molybdenum-doped BaO nanoparticles and their physical characterization

• Novel Use of Mo as Dopant : Molybdenum (Mo) doping in BaO is a novel approach that improves its band gap, optical, and electrical properties. • Enhanced Photoluminescence : Mo-doped BaO nanoparticles show enhanced photoluminescence, especially in visible range with a notable redshift. • Band Gap Reduction : Mo doping reduces the band gap of BaO from 4.3 eV to 3.8 eV (2% doping) and 3.4 eV (6% doping), improving its optical & electronic properties. • Crystallite Size Growth : XRD and Williamson-Hall analysis show that increasing Mo doping from 2% to 6% raises the crystallite size while preserving a well-ordered lattice & uniform strain distribution. • Thermal Stability : The TGA analysis reveals that Mo-doped BaO nanoparticles exhibit improved thermal stability, which is advantageous for high-temperature applications. Alkaline metal oxides have received significant attention recently due to their abundance, inherent conductivity, optical absorption, and thermal stability. Here, a straightforward co-precipitation method was employed to obtain both undoped BaO and Mo-doped BaO nanoparticles. Various techniques were used to characterize the synthesized nanoparticles’ structural, Raman spectral, optical, thermal, and electrical properties. X-ray diffraction (XRD) results revealed that Mo was successfully doped into tetragonal nanocrystalline BaO. The W-H plot showed that as Mo doping increases from 2 % to 6 %, the crystallite size grows while the lattice structure remains well-ordered with even strain distribution. Scanning electron microscopy (SEM) was used to examine its surface features. The purity and crystalline character of the samples were further confirmed via Raman spectroscopy, which shows that the peak intensity of the spectra increases with the increase of particle size owing to the rise in the force constant. UV spectroscopy was used to observe the energy band gap, which is found to decrease from 4.2 eV to 3.8 eV, and then it drops to 3.4 eV as the Mo content increases. This is reasonable because of the size-dependent attraction between metallic ions and conduction electrons. PL spectra concluded that Mo doping leads to the enhancement of the optical characteristics of BaO. Adding Mo to BaO also modifies the material’s thermal properties, potentially affecting its suitability for applications that require thermal durability. This finding exhibits that even slight doping of Mo 4+ into BaO can significantly impact their structural, thermal, optical, and electrical characteristics. It enriches the existing body of knowledge of BaO nanoparticles and lays the foundation for its future research.