The formation of direct Z-scheme Ag/BiOCl/AgIO_3 heterojunction and its degradation stability

摘要

Ag and AgIO3 were simultaneously deposited on the (001) facet of BiOCl by photoreduction method. The difference of work function between Ag and BiOCl led the electrons to flow from Ag to BiOCl, which raised the Fermi energy level of BiOCl and constructed direct Z-scheme Ag/BiOCl/AgIO3 heterojunction. The electrons that flowed from Ag to BiOCl scrambled for the holes in the primary excitons of BiOCl and formed the secondary excitons, while the electrons in the primary excitons were released and reached the conduction band of BiOCl to participate in the reduction reaction. Finally, the dissociation of excitons and separation of carriers were accelerated, and the degradation rate under solar light of Ag/BiOCl/AgIO3 to RhB was 2.8 and 4.6 times that of BiOCl and AgIO3, respectively. It could also degrade RhB under near-infrared light. Furthermore, the released electrons from the primary excitons could be accepted by AgIO3 to produce AgI, and the type-II Ag/BiOCl/AgI heterojunction was formed. The Ag/BiOCl/AgI exhibited excellent degradation stability and could still degrade RhB under near-infrared light.