Facile preparation of two-dimensional Bi^sub 2^MoO^sub 6^@Ag^sub 2^MoO^sub 4^ core-shell composite with enhanced visible light photocatalytic activity

In this paper, novel two dimensional (2D) Bi2MoO6@Ag2MoO4 core-shell composites have been successfully prepared by two-step hydrothermal and in-situ generating process. The sheet-structured composites can not only shorten the distance between the charge carriers and active sites, but provide more active sites for photocatalytic performance. Coated Ag2MoO4 nanoparticles on the surface of Bi2MoO6 nanosheets at room temperature has been verified to be an effective approach to prepare 2D core-shell composites, which benefits the formation of large-area heterojunction and boosts the separation of charge carriers. Bi2MoO2@Ag2MoO4 composites show excellent visible light photocatalytic performance and high stability. The apparent pseudo-first-order rate constant kapp for Bi2MoO6@Ag2MoO4 2:1 is 0.07255 min-1, which is 7.2 and 10.4 times higher than that of Bi2MoO6 (0.01010 min-1) and Ag2MoO6 (0.00698 min-1), respectively. Furthermore, by trapping experiment for reactive species, we demonstrate that holes play a vital role in the process of photocatalytic degradation. Eventually, a reasonable photocatalytic mechanism is proposed.