Chlorine-enhanced photocatalytic degradation of PPCPs over Bi2MoO6/(BiO)2CO3 heterostructures

Photogenerated radicals have been deemed as one of the most important determinants in photocatalytic process, which deserves an effective but demanding method to improve photocatalytic performance. Herein, we constructed Bi2MoO6/(BiO)2CO3 p-n heterostructures as photocatalysts for the degradation of pharmaceuticals and personal care products (PPCPs) in water matrix. The construction of the heterojunction optimized the energy band structure and light conversion efficiency of the photocatalyst and consequently gave rise to an improved photocatalytic activity compared with the single Bi2MoO6 and (BiO)2CO3 components. Quite significantly, the photocatalytic abilities of heterostructures could be further enhanced through the introduction of ClO- into photocatalytic process. The radicals trapping experiments demonstrated that the interaction between ClO- and heterostructures could promote the generation of free Cl radicals in photocatalysis and thus facilitating PPCPs degradation via a synergistic effect. The ClO-/heterostructures system also works well for the actual waste water purification in the presence of various common ions. This work has not only improved photocatalytic performance to a great extent, but more importantly, has put forward an idea of chlorine-assisted photocatalysis to the heterojunction system, which also has a great application prospect of waste water treatment.