Ternary novel TiO2/MgBi2O6/Bi2O3 nanocomposites with n-n-p heterojunctions: Impressive visible-light-triggered photocatalytic degradation of tetracycline

• TiO 2 /MgBi 2 O 6 /Bi 2 O 3 nanocomposites were designed as visible-light-triggered photocatalysts. • The photocatalyst has n-n-p heterojunctions for impressive segregation of the charge carriers. • Tetracycline degradation constant on the ternary photocatalyst was 46.1-folds larger than TiO 2 . • The ternary photocatalyst displayed impressive activity in removal of different pollutants. A series of novel ternary TiO 2 /MgBi 2 O 6 /Bi 2 O 3 nanocomposites were synthesized by a facile hydrothermal method. The ternary nanocomposites were characterized by XRD, FESEM, HRTEM, EDX, PL, EIS, Photocurrent, UV–vis DRS, BET, XPS, Raman, and FT-IR analyses. The photocatalytic performance of TiO 2 for the degradation of tetracycline antibiotic after combining with MgBi 2 O 6 /Bi 2 O 3 was significantly improved, which is 46.1 and 18.5 times higher than pristine TiO 2 and MgBi 2 O 6 /Bi 2 O 3 photocatalysts, respectively. Furthermore, the ternary photocatalyst efficiently degraded MO, RhB, and MB dye pollutants, which is 22.5, 30.4, and 30.0 as high as TiO 2 and 11.2, 14.4, and 17.8 folds larger than MgBi 2 O 6 /Bi 2 O 3 photocatalysts, respectively. The photoluminescence and electrochemical analyses confirmed promoted separation and facile transfer of the charges thanks to construction of n-n-p heterojunctions among n-TiO 2 , n-MgBi 2 O 6 , and p-Bi 2 O 3 components and more production of charge carriers due to integration of small band gap MgBi 2 O 6 and Bi 2 O 3 components with wide band gap TiO 2 .