Space-confined growth of Ag3PO4 nanoparticles within WS2 sheets: Ag3PO4/WS2 composites as visible-light-driven photocatalysts for decomposing dyes

A highly efficient Ag3PO4/WS2 composite photocatalyst was synthesized by controlling the growth of Ag3PO4 nanoparticles within WS2 sheets. The process can tune the microstructure, stability and visible-light photocatalytic performance of Ag3PO4. The WS2 sheets, possessing uncoordinated sulfur atoms on exposed surfaces and edges, play an important role in the formation of Ag3PO4/WS2 composite. With 0.05 mol of AgAc added, the Ag3PO4/WS2 composite shows the highest photocatalytic activity. The matched energy level between Ag3PO4 and WS2 inhibits the recombination of the photogenerated electrons and holes. The enhanced photocatalytic activity is also attributed to the multi-interface heterojunction structure assembled by two-dimensional sheets and nanoparticles, driven by chemical binding. The addition of WS2 sheets can also reduce the rate at which Ag+ dissolves from Ag3PO4 into the water, improving the stability of Ag3PO4. This work could provide new insights into fabricating highly efficient and stable Ag3PO4-transition-metal dichalcogenide composite photocatalysts for dye degradation.