Green approach synthesis of Pd@TiO2 nanoparticles: characterization, visible light active picric acid degradation and anticancer activity

Titanium dioxide (TiO2) and palladium (Pd) doped TiO2 (Pd@TiO2) nanoparticles have been synthesized using green approach technique. X-ray diffraction analysis reveals the formation of anatase phases for both pure TiO2 and Pd@TiO2. The optical properties confirm that the synthesized Pd@TiO2 eventually absorbs visible light. High resolution transmission electron microscopy analysis shows that the tiny dots seen all over the surface indicated the presence of Pd in the synthesized Pd@TiO2 nanoparticles and calculated size of the Pd nanoparticles was found to be 11 nm. Raman analysis revealed that it has pure anatase phase without any secondary phases. XPS analysis were used to study the exhibited elements present in the prepared nanoparticles which confirms the absence of any other impurities in the green synthesized Pd@TiO2 nanoparticles. The prepared pure and Pd doped TiO2 nanoparticles were used for photocatalytic and anticancer activity applications. Photocatalytic degradation of picric acid was carried out under the influence of visible light, the maximum photodegradation of picric acid was achieved within 70 min. The anticancer activity for the prepared Pd@TiO2 nanoparticles found to be enhanced, which may be attributed to the visible light absorption phenomena. Since the Pd doping on pure TiO2 surface, low bandgap energy was obtained, leading to excess electron transfer to cell lines, which increases ROS production and cell death. Hence, the green synthesized Pd@TiO2 nanoparticles had the highest anticancer activity on A549 cell lines.