Controllable preparation and optical limiting properties of CdS nanocomposites in KGM-AA soft template

Konjac glucomannan acrylates (KGM-AA) were used as soft templates to prepare the CdS nanoparticles. The structure and properties of the CdS nanoparticles were characterized and evaluated with XRD, TEM, HRTEM, TGA, UV–vis, Raman spectrum, optical limiting and nonlinear optical analyses (Z-scan technique), respectively. It was interesting to find that nanosized CdS particles successfully grew in situ and uniformly dispersed in the KGM-AA soft templates and their size and density could be effectively controlled by varying the feed ratio of Cd2+/KGM-AA. When the feed ratio is up to 17.47% (wt%), the material exhibits the best optical limiting performance with limiting threshold of 367 mJ/cm2, and good nonlinear optical properties with nonlinear absorption coefficient (α2) of 6.6023 × 10−10 cm W−1 and nonlinear refractive index (n2) of 1.27 × 10−4 cm2/GW. The optical limiting performances increase with the increase of CdS content in the composites. The optical limiting mechanism is mainly originated from the self-focusing behavior of CdS nanoparticles.