Formation of SiO₂@C-Ni magnetic nanotubes with excellent performance in 4-nitrophenol reduction

A facile and rational strategy for immobilizing nickel nanoparticles (Ni NPs) on silica nanotubes (SiO₂@C-Ni) was developed via the Stöber method, nickel ion mediated dopamine polymerization and carbonization treatment, coupled with removal of the template of one-dimensional (1D) MnO₂ nanowires (NWs). The as-prepared SiO₂@C-Ni nanotubes show vast interior space with a large specific surface area and an open channel, which offer a spacious transport channel for molecular diffusion and electron transfer. Consequently, SiO₂@C-Ni nanotubes exhibited outstanding catalytic efficiency and excellent stability for 4-nitrophenol (4-NP) reduction. Their superior catalytic activity could be ascribed to the high coverage of Ni NPs and the tubular structure of the obtained SiO₂@C-Ni, by which the silica nanotubes enhanced the accessibility of the active sites and increased the mass transfer. This facile and controllable strategy may introduce a new avenue for designing metal NP-supported composites with high dispersion for diverse applications.