A mixed Bi2O3/CQDs provides better photocatalytic activity in organic dyes pollutant model

Bismuth oxide (Bi2O3) modified carbon quantum dots (CQDs) through a hydrothermal process as a photocatalyst for the degradation of single and mixed dyes has been successfully carried out. The research was conducted through three stages: synthesis, characterization and photocatalyst activity test. The Bi2O3/CQDs composite was synthesized by adding CQDs in Bi2O3 suspension. CQDs were from citric acid and urea. Product characterization determined the band gap, crystal structure, functional groups, and morphology. Finally, Bi2O3/CQDs photocatalyst activity was tested using methyl orange (MO), rhodamine B (RhB) dyes, and a mixture of MO dyes with RhB as model pollutants. The results showed the presence of Bi2O3 in a monoclinic crystal structure, with a 1.53 eV band gap, and in a coral reef form. The Bi2O3/CQDs reduced MO and RhB dyes by 72.8 and 85.3%, respectively. Meanwhile, the degraded MO and RhB were 79.6 and 97.3% in mixed dye. This discovery proves that Bi2O3/CQDs as a photocatalyst have the potential to degrade single dyes and mixed dyes.