Study on mannitol-enhanced visible light photocatalytic degradation of mixed pollutants by BiOX

To address water pollution and limitations of existing photocatalysts, mannitol was used to fabricate tetragonal layered BiOX (X = Cl, Br, I) via a room-temperature precipitation method. Among them, BiOI with nanosheet structure exhibited broader light absorption, enhanced charge separation, and higher surface oxygen vacancies. These advantages enabled BiOI to degrade mixed pollutants (dyes, antibiotics, aromatic compounds) under visible light, achieving over 80% efficiency within 180 min. The main active species were h + and ·O 2 − . BiOI showed excellent recyclability and stability. This simple, eco-friendly synthesis offers great potential for treating complex industrial wastewater.