Simulated-sunlight-activated photocatalysis of Methyl Orange using carbon and lanthanum co-doped Bi2O3–TiO2 composite

• C/La/Bi2O3–TiO2 composite was prepared by sol-gel method.
• Carbon is deposited in Bi2O3–TiO2 composite in the form of amorphous carbon.
• Lanthanum is deposited in Bi2O3–TiO2 composite in the form of oxide.
• C/La/Bi2O3–TiO2 exhibited superior photocatalytic activity than Bi2O3–TiO2, C/Bi2O3–TiO2 and La/Bi2O3–TiO2.
• C/La/Bi2O3–TiO2 has good stability.

The C/La/Bi2O3–TiO2 composite was prepared by sol-gel method. The physicochemical properties of as-synthesized samples were characterized by the TG-DSC, FESEM, EDS, XRD, XPS, TEM, HRTEM and UV–vis DRS. Besides, their photoactivities were valuated by degrading Methyl Orange. The experimental results showed that the C/La/Bi2O3–TiO2 composite has anatase crystal structure and exhibits a remarkable optical absorption in UV–visible light region. In addition, carbon and lanthanum are deposited in the Bi2O3–TiO2 composite in the form of amorphous carbon and oxide, respectively. When the concentration of C/La/Bi2O3–TiO2 loading was 2.5 g/L, the decomposition rate of 25 mg/L Methyl Orange reached 94.3% under the irradiation of the 500 W xenon lamp after 60 min. The corresponding degradation rate constant of C/La/Bi2O3–TiO2 was 2.1, 9.2, 1.3 and 6.8 times higher than that of P25, Bi2O3–TiO2, C/Bi2O3–TiO2 and La/Bi2O3–TiO2, respectively. The reuse evaluation of C/La/Bi2O3–TiO2 indicated that its photocatalytic activity has good stability.