Facile decoration of BiMnO₃ nanoparticles over modified g-C₃N₄: S-scheme photocatalysts for impressive degradation of water contaminant upon visible light

Herein, we decorated BiMnO₃ nanoparticles on modified g-C₃N₄ (MCN) through a calcination method followed by hydrothermal heating at 180 °C. The crystalline phase, microstructure, morphology, optical properties, and specific surface area of synthesized heterojunction photocatalysts were thoroughly investigated via multiple techniques. The modified g-C₃N₄/BiMnO₃ nanocomposites (abbreviated as MCN/BMO) were employed for detoxification of antibiotics (azithromycin (AZT), tetracycline (TC), and amoxicillin (AMX)) as well as dye contaminants (fuchsine, rhodamine B (RhB), and methyl orange (MO)) upon visible light. The activity of MCN/BMO (20 %) nanocomposite for removing tetracycline was 3.52 and 43.1 folds as high as the MCN and CN photocatalysts, respectively. The action of several radical species, including electron (e⁻), anion superoxide radicals (^•O₂⁻), hydroxyl radicals (^•OH), and holes (h⁺) on the degradation reaction over the MCN/BMO (20 %) nanocomposite was explored by specific radical scavengers. Regarding band structures, scavenger testes, and photoluminescence studies, an S-scheme structure for charge transfer pathway was suggested. Furthermore, the MCN/BMO (20 %) nanocomposite showed significant activity even after four cycles. Also, the biocompatibility of the treated solution was studied via the growth of wheat seeds. Also, the integration of BiMnO₃ nanoparticles on modified g-C₃N₄ led to the establishment of a reasonable S-scheme photocatalytic mechanism, which improved the photocatalytic ability. Considering facile fabrication procedure and impressive activity, the developed novel MCN/BMO photocatalysts can be applied for the detoxification of wastewaters composed of various contaminants.