Synthesis and ammonia sensing property of Ag3CuS2 nanocages obtained from Cu7S4 18-facet hollow nanopolyhedra

Ag3CuS2 nanocages were successfully fabricated for the first time via a convenient ion-exchange route by Ag+ reacting with Cu7S4 18-facet hollow nanopolyhedra. The average size and shell thickness of Ag3CuS2 nanocages were around 400 and 30 nm, respectively. Room-temperature response of Ag3CuS2 nanocages to ammonia was investigated by photoluminescence-type sensor. Sensing results suggested that these hollow-structured Ag3CuS2 exhibited better performances including higher sensitivity, shorter response and recovery time than their rod-shape counterparts. A possible hole trapping mechanism was proposed.