Facile Fabrication and Superparamagnetism of Silica‐Shielded Magnetite Nanoparticles on Carbon Nitride Nanotubes

Abstract

Using conventional methods to synthesize magnetic nanoparticles (NPs) with uniform size is a challenging task. Moreover, the degradation of magnetic NPs is an obstacle to practical applications. The fabrication of silica‐shielded magnetite NPs on carbon nitride nanotubes (CNNTs) provides a possible route to overcome these problems. While the nitrogen atoms of CNNTs provide selective nucleation sites for NPs of a particular size, the silica layer protects the NPs from oxidation. The morphology and crystal structure of NP–CNNT hybrid material is investigated by transmission electron microscopy (TEM) and X‐ray diffraction. In addition, the atomic nature of the N atoms in the NP–CNNT system is studied by near‐edge X‐ray absorption fine structure spectroscopy (nitrogen K‐edge) and calculations of the partial density of states based on first principles. The structure of the silica‐shielded NP–CNNT system is analyzed by TEM and energy dispersive X‐ray spectroscopy mapping, and their magnetism is measured by vibrating sample and superconducting quantum interference device magnetometers. The silica shielding helps maintain the superparamagnetism of the NPs; without the silica layer, the magnetic properties of NP–CNNT materials significantly degrade over time.

Fabrication of carbon nitride nanotubes by a simple water-induced morphological transformation process and their efficient visible-light photocatalytic activity

“…Some scholars attempted to prepare C 3 N 4 NTs using catalytic self-assembly, templating, or chemical vapor deposition method. [10][11][12] However, the aforementioned processes suffer from some drawbacks, including harsh preparation conditions, operational complexity, toxicity, and high cost, which limit the large-scale preparation of C 3 N 4 NTs.…”

Synergistic oxidation of NADH on bimetallic CoPt nanoparticles decorated carbon nitride nanotubes

“…Controlled modification [3][4][5] of CNTs to incorporate functional metal nanoparticles (NPs) is crucial to realize advanced performance of the CNTs, in association with their thermal conductivity and catalytic activity. Infusion of many different NPs into CNTs has been possible primarily through exploitation of the physical adsorption and covalent bonding properties of the NTs.…”

Nitrogen-Doped Reduced Graphene Oxide Supported Pd4.7Ru Nanoparticles Electrocatalyst for Oxygen Reduction Reaction

“…The spectra are deconvoluted into pyridinic, pyrrolic, graphitic, and oxidized N peaks at 398.7, 399.8, 401.2, and 402.5 eV with ratios of 36.5, 31.9, 17.7, and 13.9%, respectively [ 30 ]. Previous research demonstrated that doped nitrogen atoms in carbon-based support, especially the pyridinic N, supply the particle anchoring sites, and the pyridinic N is dominant in this sample with the contents of 36.5% [ 7 , 8 , 18 , 31 ]. Likewise, it was proved in this research by comparing the N 1s peak of Pd 4.7 Ru NPs/NrGO and NrGO in Figure S3a .…”