Silver nanoparticles/polydopamine coated polyvinyl alcohol sponge as an effective and recyclable catalyst for reduction of 4-nitrophenol

In this work, silver nanoparticles/polydopamine coated polyvinyl alcohol (AgNPs/D-PVA) sponge were prepared via anchoring silver nanoparticles (AgNPs) on the inner wall of polyvinyl alcohol (PVA) sponge with dopamine as intermediate. The AgNPs/D-PVA were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area analyzer, X-ray diffraction pattern (XRD), thermogravimetric analysis (TG) and ultraviolet-visible (UV-vis) spectroscopy. The catalytic activity of the AgNPs/D-PVA was evaluated for the reduction of 4-nitrophenol using NaBH4 at room temperature. The coupling effect of dopamine enables AgNPs to be firmly anchored on the inner-wall of PVA sponges. AgNPs/D-PVA exhibits excellent catalytic performance for 4-NP and a good stability up to 4 cycles without a significant loss of its catalytic activity. This work develop a low-cost, high-performance and reusable of AgNPs/ D-PVA sponge for the efficient and eco-friendly conversion of toxic 4-nitrophenol into harmless 4-aminophenol, which has potential application in sewage treatment.