L-Cysteine assisted formation of mesh like Ag2S and Ag3AuS2 nanocrystals through hydrogen bonds

Biomolecules assisted formation of inorganic nanostructures facilitates the electrostatic stabilization and thus impact in the material properties. We have studied the Ag0 nuclei mediated synthesis of Ag2S nanocrystals, where L-Cysteine is utilized as sulfur source. Also, we have obtained the novel Ag3AuS2 nanocrystals by adopting the gold ions in the L-Cysteine assisted Ag2S formation. From the XRD patterns, the crystal sizes of Ag2S and Ag3AuS2 nanocrystals are calculated as 6.5 nm and 13 nm respectively. FT-IR results revealed that, Ag2S and Ag3AuS2 nanocrystals were interconnected themselves with L-Cysteine molecules through hydrogen bonding. Interestingly, the mesh like interconnected morphology has been observed in HR-TEM images in both Ag2S and Ag3AuS2 nanocrystals. The HRTEM images show the average particle size of 5.2 nm for Ag2S and 9.1 nm for Ag3AuS2 nanocrystals.