Preparation of Ni/TiO2 composite hollow fibers by electroless plating

Ni/TiO2 composite hollow fibers with an outer diameter of ca. 560 (mu)m and inner diameter of ca. 500 (mu)m were successfully prepared by electroless plating using TiO2 hollow fibers as supports. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy, energy dispersive X-ray spectroscopy (EDX), and tensile strength test. The results revealed that the Ni/TiO2 composite hollow fibers were made up of nickel outer layer and TiO2 inner layer and exhibited excellent tensile strength ascribed from the nickel layer. The thickness of the nickel layer could be readily controlled by varying the electroless time and the tensile strength of the composite hollow fibers increased with prolonging the electroless time. The tensile strength was up to 52.1 MPa when the nickel layer was ca. 22 (mu)m. The composite hollow fibers showed stable selectivities of H2 over N2 from 6 to 10 and H2 permeation in the order of 10^-9 mol m^-2 s^-1 Pa^-1 at 453 K.