The Z-Scheme Ag3PO4/Ag/WO3-x photocatalyst was prepared through an in situ deposition method. Originally, WO2.72 with hierarchical sea urchin-like structure was mixed with excessive Ag+ ions. The weak reducibility of WO2.72 was utilized to in situ reduce Ag+ into Ag, and Ag nanoparticles were deposited on the surface of WO2.72. Subsequently, an appropriate amount of PO43- ions was directly added dropwise to combine with the remaining Ag+ ions, as a result, the Ag3PO4 nanoparticles was, therefore, in situ deposited on the surface of Ag/WO3-x, and the Z-Scheme Ag3PO4/Ag/WO3-x photocatalyst was obtained. The experimental results illustrate that, for the Z-Scheme Ag3PO4/Ag/WO3-x photocatalyst, Ag nanoparticles serve as carrier-transfer centers, effectively prolong the lifetime of the photoinduced electrons generated by Ag3PO4 and the photoinduced holes generated by WO3-x, and therefore improve the photocatalytic degradation performance. The utilization of the weak reducibility of the transition metal oxides has been explored as an effective strategy to fabricate Z-scheme 'reduced state transition metal oxide/noble metal/semiconductor' photocatalysts with enhanced photocatalytic performance. (C) 2015 Elsevier B.V. All rights reserved.