Facile construction of the phase junction of BiOBr and Bi4O5Br2 nanoplates for ciprofloxacin photodegradation

The phase junction of BiOBr and Bi4O5Br2 nanoplates is constructed by controlling the basicity in one-pot hydrothermal process. The crystalline phase, morphology, optical property, chemical state of surface elements and photocatalytic performance of the obtained samples are investigated in detail. Results display that the stacked BiOBr particles are gradually transformed to Bi4O5Br2 with a multi-plate structure by increasing the pH value. The photocatalytic performance of the obtained samples is estimated by the degradation of ciprofloxacin solution under visible light. It is displayed that the photodegradation activity order is BiOBr/Bi4O5Br2 (pH = 7) > Bi4O5Br2 > BiOBr, which may be associated with the matching band structure and the efficient transfer and separation of charge. Moreover, a reasonable charge separation pathway is surveyed.