Metal oxide nanoparticles deposited onto carbon-coated halloysite nanotubes

Halloysite nanotubes (HNTs) can serve as high aspect ratio templates for the deposition of functional nanoparticles to form novel nanocomposites. We reported here on the synthesis of carbon-coated HNTs (CCH) via the carbonization of sucrose-coated HNTs in the presence of sulfuric acid. Metal oxide (MO) nanoparticles (ZnO, TiO2) were subsequently deposited on the surface of the CCH to produce MO/CCH nanocomposites. The samples were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, and N2 adsorption–desorption analysis. The results indicated that graphitic carbon could improve the conductivity of HNTs, and electron transfer across the interfaces between MO and graphitic carbon led to a significant change in photocatalytic properties. MO/CCH showed good photocatalytic performance for photodegradation of methylene blue dye. The nanocomposites had two excellent advantages as a result of the unique properties of carbon, and increased adsorption of pollutants and easy charge transportation. The as-synthesized nanocomposites could have potential application in the field of wastewater treatment.