A Ti doped carbon nanofiber (Ti/CN) catalyst was synthesized and investigated as a novel heterogeneous acid catalyst. The Ti/CN catalyst was prepared by electrospinning, preoxidation and carbonization. The fiber morphologies were characterized by scanning electron microscopy (SEM). FT-IR spectra were used to characterize the chemical structure of fiber mat. The X-ray diffraction spectroscopy (XRD) characterization demonstrated the formation of turbostratic graphite structure in carbon fiber. The catalysis results showed that the Ti/CN catalyst was very efficient for the acetalization reaction with yields over 87 %. Moreover, the larger fiber structure made the recovery of Ti/CN conveniently and the Ti/CN catalyst could be reused for five times without loss of initial activity.

Porous polyacrylonitrile (PAN) fiber mat was prepared by electrospinning PAN in N,N-dimethylformide solution with poly(methyl methacrylate) (PMMA) as pore-forming agent. Then, the porous PAN fiber mat was chemical modified by the tetraethylenepentamine to acquire aminated porous polyacrylonitrile (APPAN) fiber mat. Common aminated PAN fiber mat was also prepared for comparison. The surface morphologies of the APPAN and PAN fiber mat were characterized by scanning electron microscopy (SEM) and the corresponding specific surface areas were also measured. FT-IR/ATR spectra of the APPAN and PAN fiber mat were recorded for analysis of the surface chemical structures. The Cr(VI) absorption results demonstrated that the porous structure in the fiber could obviously increase the absorption capacity of the fiber mat.