Synthesis of silver sulfide nanowires: Variation of the morphology and structure

The beaded string silver sulfide nanowires (Ag₂S NWs) are produced by the sulfuration reaction between silver nanowires (Ag NWs) and sodium polysulfide (Na₂S_x) within the aqueous solution at room temperature. The reaction was preferentially initiated at the tip and defect of the Ag NWs, and the volume expansion occurs at the sulfurized sites due to the larger volume of silver sulfide (Ag₂S) than silver (Ag). As the reaction progresses, the sulfurized area spreads around, resulting in multiple protrusion of the Ag-Ag₂S hybrid nanowires. The lag reaction position to be unable to embed enough sulfur atoms due to the extrusion stress of expansion on both sides, leading to the formation of the flat bamboo joint sandwiched between bulges finally. This paper describes the structure evolution and morphology transformation of Ag NWs during the sulfuration process, and focuses on the studying of sulfuration mechanism.