Synthesis of barium-doped β-Bi2O3 photocatalyst with enhanced degradation of methylene blue and rhodamine-B dyes under UV–Vis light irradiation

In this study, the influence of barium (Ba) doping on bismuth oxide (β-Bi2O3) synthesized via the co-precipitation process is explored for its photocatalytic activity under UV and visible light exposure. The PXRD analysis revealed that the crystalline size decreased linearly with the addition of the dopant, indicating the successful incorporation of Ba ions into the Bi2O3 lattice. The UV-DRS spectral analysis examined the absorbance wavelength of pure β-Bi2O3 shifted towards higher wavelengths, and the band gap was reduced with the addition of Ba dopant. This suggests that the successful incorporation of Ba ions into β-Bi2O3. The morphological studies demonstrated that the flake-like structure of β-Bi2O3 transforms into a spherical-like structure upon the addition of Ba doping, leading to a decrease in agglomeration. The photocatalytic efficiency of pure β-Bi2O3 and β-Bi2O3 doped with various concentrations of Ba (0.05 M, 0.075 M, and 0.1 M) nanocatalysts was assessed for the degradation of Methylene Blue (MB) and Rhodamine-B (RhB) dyes under UV and visible light irradiation. The superior photocatalytic performance observed with the 0.1 M Ba-doped β-Bi2O3 was attributed to its narrower band-gap energy and enhanced separation and migration of photogenerated charges.