In the adsorption experiments of ethyl mercaptan gas, Fe-doped titanate nanotubes (Fe-TNT) exhibited more excellent adsorption performance than that of titanate nanotubes (TNT). This is mainly attributed to the fact that Fe-TNT has a larger specific surface area and pore volume, abundant Fe³⁺ active sites, and hydroxyl groups with stronger acidity.

Abstract

In this paper, Fe-doped titanate nanotubes (Fe-TNT) were successfully synthesized by in situ doping of Fe³⁺ ions, and the adsorption performance of ethyl mercaptan on Fe-TNT was investigated using a fixed-bed reaction device. In contrast, titanate nanotubes (TNT) were synthesized by the hydrothermal method, and the adsorption performance of TNT was examined under the same conditions. The breakthrough sulfur capacity of Fe-TNT (32.45 mg g⁻¹) is 4.3 times that of TNT (7.49 mg g⁻¹). The results of adsorption experiments show that doping Fe³⁺ ions can effectively improve the adsorption performance of the materials. In addition, the results of characterization indicate that Fe³⁺ doping does not significantly change the crystal structure, skeleton structure, and morphology of the nanotubes. However, the doping of Fe³⁺ can increase the specific surface area and pore volume of the nanotubes and provide Fe³⁺ active sites and stronger acidic hydroxyl groups, which are the main reasons for the enhanced adsorption properties of the materials.