Hydrogel-based nanocomposite catalyst containing uncoated gold nanoparticles synthesized using cold atmospheric pressure plasma for the catalytic decomposition of 4-nitrophenol

We demonstrate the synthetic route for obtaining hydrogel-based nanocomposite (h-NC), suitable for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The synthesized h-NC catalyst consisted of the uncoated Au nanostructures, produced via direct current atmospheric pressure glow discharge (dc-APGD) and immobilized into the water phase consisting of [2-(Acryloyloxy)ethyl]trimethylammonium chloride (AOETAC) further cross-linked using N,N-methylenebis(acrylamide) (MBA). Next, the so-produced h-NC was characterized to reveal the structural properties of the raw-AuNPs as well as to survey the chemical structure of h-NC. To reach this aim, several experimental techniques were used, including dynamic light scattering (DLS), transmission electron microscopy (TEM) supported by energy dispersive X-ray scattering (EDX) and selected area electron diffraction (SAED), as well as attenuated total reflectance Fourier-transform infrared spectroscopy (ATR FT-IR) for the material characterization. Finally, it was found that the h-NC facilitated the complete reduction of 4-NP to 4-AP.