Reduction–adsorption behavior of platinum ions on activated carbon fibers

A number of activated carbon fibers (ACF) were prepared by activation with steam, Phosphoric acid, or Zinc Chloride. Their reduction-adsorption behavior for Pt(IV) was studied using scanning electron microscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy. The results show that Pt ions in solution can be adsorbed by ACFs and reduced to metallic platinum. The reduction–adsorption capacity of ACF for Pt could be greater than 200 mg/g. Generally, higher specific surface area or lower electrode potential produces a higher capacity. Most of the adsorbed platinum ions were reduced into metallic platinum, and about 25% of platinum atoms remained as Pt(II) or Pt(IV). XRD examination showed that the Pt particles on the ACF surface were crystallized when heated to 673 K.