Polymer-assisted fabrication of magnetic Ni-GO catalysts with high stability for continuous flow reduction of organic pollutants

PAMD strategy stabilizes Ni nanoparticles on graphene oxide supports. • Ni–GO shows superparamagnetism for facile magnetic separation and reuse. • 95% 4-NP conversion in 2 min with first-order rate constant 3.02 × 10 −2  s −1 . • Continuous-flow reactor runs 12 h at 5 mL min −1 keeping >90% conversion. • Catalyst retains 90% activity after 2100 cycles with stable structure. A polymer-assisted metal deposition strategy is developed to fabricate nickel loaded graphene oxide (Ni-GO) composites with enhanced catalytic stability. GO is first functionalized via silane coupling and surface polymerization, creating effective anchoring sites for uniform Ni nanoparticle deposition. The resulting Ni-GO composite exhibits superparamagnetic behavior with a saturation magnetization of 6.75 emu g −1 , enabling rapid magnetic recovery. In batch reduction of 4-nitrophenol, the catalyst achieves over 95% conversion within 2 min and follows first-order kinetics with a rate constant of 3.02 × 10 −2  s −1 at 30 mg catalyst dosage. A continuous-flow reactor packed with Ni-GO maintains >90% conversion for 12 h at 5.0 mL min −1 . Scale-up configurations including series and parallel assemblies demonstrate stable performance up to 50 mL min −1 . The composite also effectively degrades methyl orange, rhodamine B and methylene blue, and hydrogenates various nitroaromatic compounds with >80% conversion. After 2100 catalytic cycles, the material retains 90% efficiency with negligible structural change. This work offers a practical route to stable non-noble metal catalysts for continuous pollutant treatment. A polymer-assisted metal deposition method anchors Ni nanoparticles on functionalized GO, yielding a magnetic catalyst that reduces 4-nitrophenol in 2 min, sustains >90% conversion for 12 h in continuous flow, and retains 90% activity after 2100 cycles. Download: Download high-res image (41KB) Download: Download full-size image