Facile synthesis of α/β-Bi2O3 hetero-phase junction by a solvothermal method for enhanced photocatalytic activities

A novel α/β-Bi2O3 hetero-phase junction (xBB) was successfully prepared by a simple in-situ growth method without further calcination, in which α-Bi2O3 served as the substrate for the growth of β-Bi2O3 nanosheets. The nanocomposites were well characterized by XRD, SEM, TEM, UV–vis DRS, XPS, EIS, etc. The characterizations testified that the bismuth oxides of two crystal phases were in close contact, and the hetero-phase junction was formed. The photocatalytic performance was evaluated by degradation of rhodamine B (RhB) and tetracycline hydrochloride (TC-HCl) under visible light illumination. With the optimum mass ratio, 0.5BB sample exhibited the highest photocatalytic activity, the removal rates were 82.7 % for TC-HCl in 120 min and 94.9 % for RhB in 90 min, and a rate constant of 0.0297min−1 was evaluated for RhB degradation, which were higher than that of pure α-Bi2O3 (0.0019 min−1) and β-Bi2O3 (0.0028 min−1) by a factor of 15.6 and 11.9, respectively. The synthetic method provides a promising route for the in-situ construction of hetero-phase junction nanocomposites.