Novel Fork Architectures of Ag2S Nanoparticles Synthesized Through In-Situ Self-Assembly Inside Chitosan Matrix

In a simple reaction between Silver nitrate and Thiourea under the presence of Chitosan, novel fork architectures of silver sulfide (Ag2S) were obtained through In-situ self- assembly of Ag2S nanoparticles inside Chitosan matrix in aqueous basic environment. Samples were characterized by SEM, TEM, XRD, FTIR, Raman Spectroscopy and UV-vis Spectroscopy. Average particle size was found to be 8 nm from TEM analysis. Formation of crystalline monoclinic alpha-Ag2S was confirmed by SAED and X-ray diffraction analysis. The experimental results show that the fork architectures of Ag2S can be obtained from Tape like assemblies of Ag2S nanoparticles at the later stage of their growth with temperature. Raman spectra confirm the incorporation of Ag2S nanoparticles inside Chitosan matrix. Multiple resonant Raman peaks indicates that the yielded Ag2S nanoparticles possess good optical quality and crystalinity. FTIR spectra indicates that the Ag+ ion is coupled with the C=O bond of the Chitosan molecules through the electrostatic interaction. UV-vis absorption spectrum of the Ag2S Fork architectures has a broad absorption band in the UV to visible region, and the blue-shifting of the band is observed along with the presence of both direct and indirect band gap.