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 Stober 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.

Automated summary

A facile and rational strategy was developed for immobilizing nickel nanoparticles on silica nanotubes, resulting in SiO2@C-Ni nanotubes with outstanding catalytic efficiency and stability for 4-nitrophenol reduction. The high coverage of Ni nanoparticles and the tubular structure of SiO2@C-Ni were responsible for the enhanced accessibility of active sites and increased mass transfer. This strategy provides a new avenue for designing metal nanoparticle-supported composites with high dispersion.