Improved electrocatalytic activity of ethanol oxidation over Pd/TiO2 nanofibers-carbon black nanocomposite

Abstract

Herein, titanium dioxide nanofibers (TiO2 NFs) were successfully prepared using sol-gel combined electrospinning method and subsequent calcination at 600 °C. The TiO2 NFs were used for preparation of TiO2 NFs-carbon black composite including Pd nanoparticles (Pd/TiO2 NFs-C). The prepared samples were characterized by field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), thermal gravimetric analysis (TGA) and N2 adsorption-desorption isotherm (BET). The FE-SEM showed that the polyvinyl pyrrolidone/titanium tetraisopropoxide composite (average fiber diameter: 125 nm) and TiO2 NFs (average fiber diameter: 48 nm) were obtained. TEM micrograph showed a relatively good dispersion of the Pd nanoparticles with average diameters at about 31 nm over TiO2 NFs-C composite. Using XRD, anatase and rutile crystalline phases for the TiO2 NFs and face center cubic (fcc) structure for Pd were identified in the nanocomposite. The dispersed Pd nanoparticles onto the TiO2 NFs-C showed a specific electro-catalytic activity in EOR with j = 17.6 mA cm−2, 6.4-fold improvement than that of traditional Pd/C catalyst.