Bandgap and visible-light-induced photocatalytic performance and dye degradation of silver doped HAp/TiO nanocomposite by sol-gel method and its antimicrobial activity.

Silver doped hydroxyapatite and titanium oxide nanocomposites have been obtained by sol-gel techniques with novel antimicrobial activities for biomedical applications. The synthesis of Ca Ag (PO)(OH) along with titanium oxide nanoparticles with X = 0 (HAp/TiO), 0.1, 0.25 and 0.5 (Ag:HAp/TiO-NCS) was performed. The developed crystalline phase was characterized via X-ray diffraction (XRD), and the morphological features were executed via scanning and transmission electron microscopy (SEM/TEM). The HAp/TiO and silver doped HAp/TiO nanocomposites were spherical grains, with needle and flower-like structures. XRD examination revealed the crystalline phases of HAp/TiO and Ag-doped HAp/TiO nanocomposites. The crystallite size of HAp/TiO and Ag-doped HAp/TiO nanocomposites determined from the XRD pattern was ranged between 16 nm and 20 nm. The FTIR analysis confirms the presence of stretching and vibrational peaks for the presence of silver doped HAp/TiO. The EDAX analysis showed the existence of major elements of HAp/TiO and Ag-HAp/TiO nanostructured composites. HAp/TiO and silver doped HAp/TiO were active against both Gram-positive and Gram-negative bacteria such as, E. coli (MTCC 443), S. typhi (MTCC 733), and S. aureus (MTCC 3160). The photocatalytic absorption spectrum implied an increased absorption rate of methylene blue by HAp/TiO and silver doped HAp/TiO nanocomposites. The photocatalytic activity revealed that 50% Ag doped HAp/TiO optimally improved photocatalytic activity.