Ag3PO4/In2S3 composites with ultra-low loading of Ag3PO4 were prepared.
Loading of ultra-low Ag3PO4 greatly improved the activity of In2S3.
Ag–Ag3PO4 served as cocatalyst during photocatalysis.
A Z–scheme mechanism among Ag/Ag3PO4/In2S3 was proposed.
The activity enhancement was also observed over Ag3PO4/ZnIn2S4 composites.