In situ prepared nanosized Pt-Ag/PDA/PVA-co-PE nanofibrous membrane for highly-efficient catalytic reduction of p-nitrophenol

Combining highly-active noble metal nanoparticles and unique 3D nanofibrous structure is significant to enhance their intrinsic properties such as catalytic performance. Here, we prepared a poly (vinyl alcohol-co-ethylene) (PVA-co-PE) nanofibrous membrane (NFM) decorated by polydopamine (PDA) via a melt-phase-separated nanofiber-suspension coating followed by in-situ polymerization. The as-prepared PDA modified NFM worked as the in-situ reducing agent to capture silver ions and transfer them to Ag nanoparticles (NPs). Then Ag/PDA/NFM was further coated with Pt NPs by magnetron sputtering technique. The morphology and structure analysis showed that the Ag NPs in diameter from 10 to 200 nm and Pt nanoparticles coating has been successfully immobilized on PDA/NFM. The catalytic rate constant of Pt-Ag/PDA/NFM in the reduction reaction of p-nitrophenol (p-NP) was about 34.43×10-3 s-1 higher than that of Ag/PDA/NFM (30.20×10-3 s-1) and Pt/PDA/NFM (0.188 ×10-3 s-1), respectively, when magnetron sputtering time of Pt was 100 s. It can be attributed to the electronic effect in bimetallic catalyst and the enhancement effect of nanofibrous membrane with high specific surface area. Furthermore, Pt-Ag/PDA/NFM presented an excellent cyclic feature that still about 98% conversion of p-NP after 6 times implying its superiority in reduction degradation of p-nitrophenols.