Carbon xerogel/carbon nanotubes nanohybrid doped with Ti for removal of methylene blue dye

Abstract

AFACILE technology for decorating carbon xerogel (CX) with carbon nanotubes (CNTs) to prepare carbonaceous nanohybrid (CX-CNTs) was simultaneously implemented during carbonization of resorcinol-formaldehyde xerogel at 1123K meanwhile camphor as carbon nanotubes source is heated at 523K. Then the prepared CX-CNTs hybrid is doped with tetrabutyl orthotitanate as a titanium (Ti) precursor giving CX-CNTs-Ti nanohybrid used as an efficient photocatalyst. The morphology and textural properties of the samples were investigated using field-emission scanning electron microscope (FE-SEM), High resolution transmission electron microscopy (TEM) and N2 adsorption-desorption isotherm at 77K. The adsorption and photocatalytic properties of these samples toward methylene blue dye (MB) were performed. FE-SEM and TEM approved the formation of CNTs over the surface of CX and the developed nanohybrids have mesoporous structures. The adsorption efficiency of CX-CNTs and CX-CNTs-Ti samples was found to be 70 and 86.8% along 180 min, respectively. Under visible irradiation, the removal efficiency of CX-CNTs and CX-CNTs-Ti is enhanced to 90 and 99% at 60 min, respectively. Thus, CX-CNTs-Ti nanohybrid exhibited superior adsorptivity and photoactivity for removing MB dye as a result of the presence of Ti particles over CX-CNTs matrix. Doping CX-CNTs with Ti particles led to a decrease in the specific surface area and to enhance in both the total pore volume and amount of wider pores. Therefore, the reported CX-CNTs-Ti nanohybrid exhibits as an effective adsorbent and photocatalyst toward the removal of the MB dye from their aqueous solutions.