Synthesis, structural, optical linear and nonlinear investigations of Au-doped TiO₂ nanoparticles

Gold-doped TiO 2 nanoparticles (NPs) were synthesized using a hydrothermal precipitation decomposition method. The synthesized Au–TiO 2 NPs have two crystalline structures, anatase and rutile. The X-rays were used to investigate the structural properties of the samples. The XRD confirmed the incorporation of Au in TiO 2 . The diffuse reflection spectroscopy (DRS) technique was used to investigate the samples’ linear optical properties and band gaps. The optical properties revealed an extended tailing with a surface plasmon resonance (SPR) absorption peak. The bandgap was redshifted due to the Au incorporation. The reflection Z-scan (RZ-scan) technique was employed to study the nonlinear optical refraction and absorption coefficients of Au-doped TiO 2 NPs at 514[Formula: see text]nm wavelength. The nonlinear reflection and absorption coefficients were calculated by fitting theoretical equations to the experimental data. Hence, the nonlinear properties of gold-doped TiO 2 nanoparticles may find potential applications for optoelectronic devices such as optical switches and safety devices against high-power laser beams.