Synthesis of α-Bismuth oxide nanoparticles, spectral characterization and their photocatalytic activity

α-Bismuth oxide nanoparticles (α-BiNPs) were synthesized using oxalic acid as a reducing agent. Synthesized nanoparticles were characterized by Ultraviolet-Visible spectroscopy (UV Vis-DRS), Photoluminescence (PL), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Thermo gravimetric-Differential Thermal analysis (TG-DTA), and High-Resolution Transmission electron microscopy (HR-TEM) coupled with selected area electron diffraction (SAED) pattern. The UV–DRS spectrum reveals the blue shift of absorption edge and the bandgap energy. The XRD pattern revealed the crystalline nature of the synthesized α-BiNPs. The decomposition of the samples was analyzed by TG-DTA analysis. The HR-TEM morphology confirms that the nanoparticles are in an irregular shape. The FT-IR spectrum confirms the Bi-O bond in α-BiNPs. The α-BiNPs exhibit 87 and 84% of photocatalytic activity against MB and CV. Therefore, the synthesized α-BiNPs can be used as a photocatalyst for environmental applications.