Solvothermal synthesis, morphology, and optical properties of Bi2O3 and Bi/Bi2O2.75 powders

Bi2O3 nanomaterials were synthesized via a facile solvothermal routine both in the absence and presence of reducing agent of ascorbic acid. XRD measurements were applied to confirm the phase formation and structure. The morphological, optical absorbance, photocatalytic activities, and photoluminescence of the final samples showed a strict dependence on the presence of reductant used in the synthesis. Solvothermal synthesis without ascorbic acid produced alpha-Bi2O3 nanoplates, which aggregated together forming the flowerlike balls. Due to the in situ reduction of bismuth ions by ascorbic acid, the ball-like Bi/Bi2O2.75 nanocomposites (100 nm) were obtained in the presence of reducing agent via introducing the metallic Bi-0 on the surface. The photocatalytic and photoluminescence activities of the samples were investigated. Bi/Bi2O2.75 nanocomposites showed a good photocatalytic behavior on the degradation of organic dye solutions. The photocatalysis was discussed on the luminescence, decay lifetime, and multivalent ions.