Solvothermal-based synthesis of barium stannate nanosheets coupled with copper manganate nanoparticles for efficient photooxidation of tetracycline under visible light

Photocatalytic oxidation of antibiotic waste over semiconducting heterojunction photocatalysts is considered eco-friendly because it is simple and operates under light irradiation. In this work, we apply a solvothermal-based process for obtaining high surface area barium stannate (BaSnO3) nanosheets followed by adding 3.0∼12.0 wt.% of spinel copper manganate (CuMn2O4) nanoparticles to form n-n CuMn2O4/BaSnO3 heterojunction photocatalyst after calcination process. The CuMn2O4-supported BaSnO3 nanosheets exhibit mesostructure surfaces with a high surface area range of 133-150 m2 g-1. Moreover, introducing CuMn2O4 to BaSnO3 shows a significant broadening in visible light absorption range due to bandgap reduction down to 2.78 eV in 9.0% CuMn2O4/BaSnO3 compared to 3.0 eV for pure BaSnO3. The produced CuMn2O4/BaSnO3 is used for photooxidation of tetracycline (TC) in water as emerging antibiotic waste under visible light. The photooxidation of TC exhibits the first-order reaction model. The specific dose of 9.0 wt. % CuMn2O4/BaSnO3 at 2.4 gL-1 displays the highest-performed and recyclable photocatalyst for total oxidation of TC after 90 min. This sustainable photoactivity is attributed to the improved light harvesting and charges migration upon coupling between CuMn2O4 and BaSnO3.