Copper sulfide nanosheets with shape-tunable plasmonic properties in the NIR region

Abstract

2D copper sulfide nanocrystals are promising building blocks for plasmonic materials in the near-infrared (NIR) spectral region. We demonstrate precise shape and size control (hexagonal/triangle) of colloidal plasmonic copper sulfide (covellite) nano-prisms simply by tuning the precursors concentration without introduction of additional ligands. The ultra-thin 2D nanocrystals possess sizes between 13 and 100 nm and triangular or hexangular shapes. We also demonstrate CuS nanosheets (NSs) with lateral sizes up to 2 microns using a syringe pump. Based on the experimental findings and DFT simulations we propose a qualitative and quantitative mechanism for the formation of different shapes. The analysis of the spectral features in the NIR of synthesized CuS nanocrystals has been performed in respect to the shape and the size of particles by the discrete dipole approximation method and the Drude-Sommerfeld theory.

Micron-Size Two-Dimensional Methylammonium Lead Halide Perovskites

“…These findings indicate that the sheets are formed either from small particles which agglomerate and merge, or that the precursors meet in some sort of micelle in the shape and size of the end product prior to nucleating, similar to PbS nanosheets 24 and in contrast to the continuous growth mechanism of different colloidal materials. 25,26 presented is constituted by several factors and is different for MAPbI, MAPbBr, MAPbCl, respectively. In some cases, two or three parameters are responsible for the lateral growth such as temperature and amount of ligand.…”

Efficient NIR energy conversion of plasmonic silver nanostructures fabricated with the laser-assisted synthetic approach for endodontic applications

“…The same observation was reported by Kelly 39 and Lesyuk. 40 In conclusion, by adopting this synthetic protocol, one can fabricate the Ag-NP with different plasmonic properties covering the spectral range from UV to NIR that opens several interesting possibilities for biological applications.…”

Tuning the Dimensionality of Nano Ca(OH)2 with Surfactants for Wall Painting Consolidation

“…These results indicate that OPPE prefers to absorb on the (0001) facet of Ca(OH) 2 and DMF is prone to coordinate with the facet of Ca(OH) 2 . As a result, the coverage of OPPE on the two (0001) facets forms a barrier layer that prevents the facet growth (Figure (e)) . Hence, the crystal growth occurs dominantly along the (0001) facet direction, resulting in the increase in diameter and a decrease in thickness with the increase of the OPPE concentration (Figure (b)–(d)).…”

“…As a result, the coverage of OPPE on the two (0001) facets forms a barrier layer that prevents the ð1010Þ facet growth (Figure 3(e)). [26,27] Hence, the crystal growth occurs dominantly along the (0001) facet direction, resulting in the increase in diameter and a decrease in thickness with the increase of the OPPE concentration (Figure 1(b)-(d)). Similarly, a majority of DMF molecules will attach to the surface of the six ð1010Þ facets of Ca(OH) 2 to form a barrier layer on the six ð1010Þ facets, which restrain the growth of the (0001) facet of Ca(OH) 2 (Figure 3(f)).…”