Print: | ISSN 0256-1115 |
Online: | ISSN 1975-7220 |
Korean Journal of Chemical Engineering,
Vol.25, No.4, 775-779, 2008 Preparation of platinum-doped hollow spheres and their electrocatalytic activity in water electrolysis
Pure TiO2 hollow spheres were prepared by using poly(styrene-methacrylic acid) latex particles as template; thereafter, titania hollow spheres were coated by platinum with an appropriate amount of choloroplatinic acid solution to obtain Pt/TiO2 catalysts. The morphology and structure of nonstructural Pt/TiO2 hollow spheres were characterized by BET, XRD, TGA, SEM and TEM analysis. In the samples, a remarkably uniform layer of Pt consisting of particles from 5 to 70 nm in size was formed over TiO2 hollow spheres. We found the electrocatalytic nature of the samples by cyclic voltammetric experiment in acidic solution. The anodic peak current density of 20 wt% Pt-loaded TiO2 hollow particles was observed 2.5 times higher than that of 5 wt% Pt/TiO2 in the same experimental condition. Also, the anodic current density of 20 wt% Pt/TiO2 hollow spheres calcined at various temperatures followed the order: 400 ℃.500 ℃>600 ℃. The electrocatalytic activity of the Pt-loaded TiO2 hollow spheres depends on the amount of atomic platinum present in the sample; a higher concentration of platinum results in a larger current density value in anodic sweep, resulting in more oxygen production during electrolysis. Pt/TiO2 hollow sphere catalysts have also shown long term electrocatalytic stability in acidic media.
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