Synthesis of novel Z-scheme AgI/Ag/AgBr composite with enhanced visible light photocatalytic activity

Novel Z-scheme AgI/Ag/AgBr composite was synthesized through a facile in-situ ion exchange method along with light reduction. The as-prepared AgI/Ag/AgBr was characterized by XRD, SEM, DRS, XPS, EDS, BET and PL technology to study its phase structures, morphologies, optical properties, element components and surface areas. AgI/Ag/AgBr displayed excellent photocatalytic activity for the degradation of methyl orange under visible light (λ > 420 nm), which can be ascribed to the efficient separation of photogenerated electrons and holes through Z-scheme system composed of AgI, Ag and AgBr. The photocatalytic mechanism investigation demonstrates that •O2− was the main reactive species for methyl orange (MO) degradation.

► Novel Z-scheme AgI/Ag/AgBr composite was reported for the first time. ► AgI/Ag/AgBr was prepared by ion exchange method followed by light reduction. ► AgI/Ag/AgBr displayed excellent visible light photocatalytic activity. ► The resulting •O2− played the major roles for MO degradation. ► Photo-induced carriers can be effectively separated by Z-scheme AgI/Ag/AgBr.