Ag2S Nanoparticles Evolved into Luminescent AgInS2@In2S3 Heteronanoparticles through Dual Formation Mechanism

Abstract

AbstractA deep understanding of the growth kinetics and mechanism of metal sulfide nanostructure is helpful in preparing nanomaterials with controllable structures. This study reports a facile synthetic protocol for the luminescent AgInS2@In2S3 core@shell heteronanoparticles through the reaction of preformed Ag2S nanoparticles with excess [(C4H9)2NCS2]3In in dodecanethiol. A dual formation mechanism for the orthorhombic AgInS2 (o‐AgInS2) component is proposed, that is, the cation exchange of partial Ag+ in Ag2S nanoparticle by In3+ to produce the metastable AgInS2 and alloying of the In2S3 formed through direct decomposition of [(C4H9)2NCS2]3In with Ag2S nanoparticles to produce AgInS2. Following the dual formation mechanism, the Ag2S nanoparticle first evolves into the intermediate Ag2−3δInδS/o‐AgInS2 Janus heteronanoparticle without band‐edge emission of o‐AgInS2, then converts to the o‐AgInS2 nanoparticle, and finally transforms to the o‐AgInS2@In2S3 core@shell heteronanoparticle with band‐edge emission of o‐AgInS2. The appearance of band‐edge emission might be attributed to the removal of the surface defects of the o‐AgInS2 core by coating the In2S3 shell. This study would provide a facile protocol for the synthesis of IB‐IIIA‐VIA2 nanomaterials with controlled architecture and benefit the development of monochromatic luminescent apparatus.