Abstract
The effects of annealing in air and anodizing on the capacitive behavior of carbon-ruthenium (denoted as C-Ru) composites fabricated by wet impregnation were investigated in 0.1 M H 2 SO 4 by cyclic voltammetry (CV) and chronopotentiometry (CP). The utilization of Ru species within the thick composites (≈1000 μm) was greatly promoted by annealing in air at 240 °C for 8 h and anodizing in 0.1 M H 2 SO 4 at 1.2 V for 1.5 h, due to the formation of Ru oxide and the transformation into a hydrous nature and the maximal specific capacity of Ru oxide (760 F g -1 based on RuO 2 ) could be obtained. The crystalline information of the composites with annealing at different temperatures was obtained from X-ray diffraction (XRD) patterns. The morphology of C-Ru composites was examined by scanning electron microscope (SEM). The specific surface area and pore-size distribution of the composites with annealing and/or anodizing were analyzed by the BET method. © 2002 Elsevier Science B.V. All rights reserved.