Ternary AgBiS₂ Nanocrystals: Surface and Facet Modulations

Introducing different halide precursors, varying reaction temperature, and tuning the precursor ratios, facet-modulated ternary AgBiS₂ (ABS) nanocrystals having cube, tetrahedron, octahedron, and truncated cube shapes are reported. With extensive electron microscopy imaging and analysis, the chemistry of formulation, facet reconstruction, and again the shape change of these nanocrystals at higher reaction temperature are investigated. These are the low-band-gap semiconductors that absorb in the near-IR (NIR) region, and, hence, their photoresponse under NIR irradiation has been studied and correlated. Further, these nanocrystals are also applied for electrochemical water reduction, and their results are summarized. While ABS has been widely studied in bulk, their nanocrystals with different facet modulations not only add to the fundamental chemistry of colloidal synthesis but also contribute as effective semiconductor nanomaterials with NIR-absorbing properties.