In this study, we employed one of the green synthesis methods utilizing water extracts prepared from solid industrial wastes of Rosa damascena Mill. (RD) and Oriental variety tobacco (Nicotiana tabacum)-mixed stems and leaves (O) as a natural reducing agent for PdCl2 to obtain environmentally friendly Pd nanoparticles (PdNPs). Transmission electron microscopy (TEM), selected area electron diffraction (SAED), and energy-dispersive X-ray spectroscopy (EDX) in TEM were applied to determine the morphology, microstructure, phase, and elemental composition of PdNPs synthesized. The concentration of PdNPs in the suspensions was quantified by inductively coupled plasma optical emission spectroscopy (ICP-OES), which is essential for their intended application. Furthermore, the synthesized PdNPs were incorporated as dopant into a polymer matrix (PAZO) developed for optical applications. As will be demonstrated, doping PAZO with specific concentrations (0.1, 0.2, 0.25, 0.3, 0.4, 0.5, and 1 wt. %) of green PdNPs enhances the maximal value of the photoinduced birefringence by more than 50%. This improvement enables more efficient inscription of polarization-selective holographic optical elements in the resulting photoanisotropic nanocomposite materials with nearly 25% higher diffraction efficiency. Using a digital polarization holographic setup, the spatial modulation of polarization was recorded on thin nanocomposite films of the azopolymer PAZO, doped with certain concentrations of the green PdNPs.
Georgieva et al. (2026) studied this question.