We prepared BiOCl, BiO(ClBr), BiO(ClBrI), and BiO[ClBrI(CO3)0.5] materials using a simple coprecipitation
method. It was found that adjusting the number of anions in the anion
layer was conducive to adjusting the band structure of BiOX and could
effectively promote the migration and separation of photogenerated
carriers, thus improving the photocatalytic activity. We first selected
methyl orange (MO) as the study pollutant and compared it with BiOCl,
BiO(ClBr), and BiO(ClBrI). The first-order kinetic constants of MO
degradation by BiO[ClBrI(CO3)0.5] increased
by 90.3, 33.9, and 3.1 times, respectively. The photocatalytic degradation
rate of methylene blue by BiO[ClBrI(CO3)0.5]
was 89.5%, indicating the excellent photocatalytic performance of
BiO[ClBrI(CO3)0.5]. The stability of BiO[ClBrI(CO3)0.5] was demonstrated through cyclic experiments
and XRD analysis before and after the reaction. The photocatalytic
degradation of MO by BiO[ClBrI(CO3)0.5] showed
that h+ and 1O2 were the main active
oxidizing species and •O2
– was
the secondary active substance. Overall, our work provides new ideas
for the synthesis and degradation of organic pollutants by using two-dimensional
anionic high-entropy materials.