Facile In Situ Self-Sacrifice Approach to Ternary Hierarchical Architecture Ag/AgX (X = Cl, Br, I)/AgIO3 Distinctively Promoting Visible-Light Photocatalysis with Composition-Dependent Mechanism

Three series of ternary hierarchical architecture photocatalysts Ag/AgX (X = Cl, Br, I)/AgIO3 were fabricated for the first time by a facile in situ ion-exchange route. The novel ternary architectures are confirmed by XRD, XPS, SEM, TEM, EDX, and EDX mapping. In contrast to pristine AgIO3, the Ag/AgX (X = Cl, Br, I)/AgIO3 composites show extended absorption edges and highly boosted photoabsorption in the visible region, which are separately ascribed to the intrinsic absorption of AgX and the surface plasmon resonance (SPR) effect of Ag species. The photocatalysis activity of Ag/AgX (X = Cl, Br, I)/AgIO3 composites is studied and compared via photodegradation of methyl orange (MO) under visible-light (lambda > 420 nm) irradiation. It is interesting to find that the activity enhancement levels are different for Ag/AgX (X = Cl, Br, I)/AgIO3 with four types of photocatalytic mechanism, which are closely related to the type of AgX or the component content in Ag/AgX (X = Cl, Br, I)/AgIO3. The separation behaviors of charge carrier were also systematically investigated by the PL and EIS. The study may furnish new perspective into controllable fabrication of hierarchical architecture photocatalysts with multiform photocatalytic mechanism.