Construction of a novel two-dimensional AgBiO 3 /BiOBr step-scheme heterojunction for enhanced broad-spectrum photocatalytic performance

Efficient S-scheme heterojunction photocatalysts were prepared through in situ growth of AgBiO 3 on BiOBr. The self-assembled hierarchical structure of AgBiO 3 /BiOBr was formed from flower-like AgBiO 3 and plate-like BiOBr. The optimized AgBiO 3 /BiOBr heterojunction possessed excellent visible-light photocatalytic degradation efficiency (83%) for ciprofloxacin (CIP) after 120 min, with 1.46- and 4.15-times higher activity than pure AgBiO 3 and BiOBr, respectively. Furthermore, the removal ratio of multiple organic pollutants including tetracycline, Rhodamine B, Lanasol Red 5B and methyl orange was also investigated. Environmental interference experiments demonstrated that high pollutant concentrations, low photocatalyst dose and the addition of ions (SO 4 2− , PO 4 3− , HPO 4 2− , H 2 PO 4 − ) inhibited the photocatalytic activities. Subsequently, a simultaneous degradation experiment showed the competitive actions between CIP and RhB for radicals, decreasing the photocatalytic activity of CIP. Furthermore, trapping and electron spin resonance experiments showed that h + and ˙O 2 − played a certain role in the degradation process and that ˙OH acted as assistant.