Gold Nanoparticles Adorned Polydopamine-Functionalized Zn–Al-Layered Double Hydroxide as Reusable Novel Nanocatalyst Towards the Reduction of Harmful Dyes of Water

Abstract

The current study brings in the nano-architectonics and chemical production of Au NP doped polydopamine (PDA)-modified Zn–Al-LDH or layered double hydroxide (Zn-Al LDH@PDA). The green synthesized Au adornednano-substance has been so novel where the support Zn-Al LDH@PDA provides the necessary protection ofAu NPs by encapsulation. The polyamino atmosphere in the surface of the PDA facilitates the strong binding or coordination of incoming Au ions.In order to ascertain the physicochemical properties of the material, we utilized an extensive array of advanced techniques in this process, such as elemental mapping, FT-IR, FE-SEM, EDX, TEM, HR-TEM, FFT, ICP-OES, N₂ surface adsorption-desorption, and XRD. Subsequently we evaluated catalytic exploration of the Zn-Al LDH@PDA/Au nanocomposite to reduce the harmful dyes of water like Methyl Orange, Methylene Blue and 4-nitrophenol using NaBH₄ as the hydride donor. The outstanding potential of the catalyst was then confirmed by using a time-dependent UV-Vis spectroscopy approach to monitor the chemical reaction and see how the absorptions decreased with time. It was also clear the reaction rate is proportional to catalyst load and kinetic study assured the reaction to be of pseudo-first order. In the end, we managed to isolate the nanocatalyst through centrifuger and found it sufficiently robust so that it could be recycled in an 8successive period with no significant decline in reactions.