Regulation of visible-light-driven photocatalytic degradation of Rhodamine B on BiOBr via zeta potential

In this paper, bismuth oxybromide (BiOBr) photocatalysts were synthesized in the presence of tetrabutylammonium bromide (TBAB) at the different volume fractions of ethanol/water and named as BiOBr 0 , BiOBr 20 , BiOBr 50 , BiOBr 80 and BiOBr 100 , respectively. The samples were characterized and applied to the degradation of Rhodamine B (RhB) under visible-light irradiation ( λ  ≥ 420 nm). The results indicated that both TBAB and ethanol significantly affected the crystal phase, morphology and surface charge distribution of BiOBr. The exposed (110) faces of BiOBr with Bi 3+ sites contributed to its photocatalytic activity via the enhanced separation of electrons and photogenerated holes as well as the better photo-stability. BiOBr 50 showed the optimal activity for the photodegradation of RhB. Superoxide radical (O ·− 2 ) as the dominant active species was responsible for the degradation of RhB.