Enhanced photoreduction of mercury (II) ions over MnCo2O4-modified wrinkled BaSnO3 nanosheets prepared by solvothermal method under visible light

Photocatalytic reduction of heavy metal ions utilizing nanostructured semiconductor photocatalysts is a promising ecological way, thanks to its simplicity and feasibility. In this article, the improved photoreduction of mercury (II) ions (Hg2+) is achieved over wrinkled barium stannate (BaSnO3) nanosheets modified by manganese cobaltate (MnCo2O4) nanoparticles. The MnCo2O4 was coupled to solvothermally-produced BaSnO3 at 4.0–16.0 wt% by impregnation. The MnCo2O4/BaSnO3 heterojunctions showed mesoporous surfaces with 133–150 m2 g1 of surface areas. The visible light harvesting is improved owing to bandgap reduction down to 2.31 eV for 9.0 wt% MnCo2O4-impregnated BaSnO3 compared to 2.99 eV for the bare BaSnO3. The complete photoreduction of 368.30 µM Hg2+ utilizing 9.0% MnCo2O4/BaSnO3 is achieved at a dosage of 2.4 gLẌ with a rate of 69.54 µM min–1 in 30 min. This optimized photocatalyst is also recyclable five times with 97% of its initial performance. The magnificent activity of MnCo2O4/BaSnO3 is accredited to the improved visible-light harvesting and efficient charge separation by the controllable impregnation of MnCo2O4. [Display omitted] •159 m2g–1 wrinkled nano BaSnO3 sheets were synthesized by solvothermal route.•Impregnation of 4.0–16.0 wt% MnCo2O4 nanoparticles forming n-n heterojunctions.•MnCo2O4 induced visible light harvesting and bandgap reduction to 2.31 eV.•Photoreduction of Hg2+ enhanced by > 13.1 times at 69.54 µM min–1 compared to BaSnO3.•Stable heterojunction photocatalyst for five runs.