2012 Volume 80 Issue 5 Pages 324-326
The current density of gas-diffusion biocathodes for the oxygen reduction in biofuel cells was successfully increased by adjusting the hydrophobicity of porous carbon electrodes and by adding small amount of non-ionic surfactant to enzyme solution to be used in the enzyme adsorption process. Optimization of the hydrophobicity was performed with non-glycoprotein cupper efflux oxidase as an electrocatalyst. Carbon slurry was prepared by mixing Ketjen black and polytetrafluoroethylene in 2-propanol at a weight ratio of 3:2. Carbon paper was modified with the slurry and dried at 60°C to remove the solvent. Addition of small amount of non-ionic surfactant such as Triton X-100 (about 0.01%) into the enzyme solution was very effective to adsorb the enzyme on the hydrophobic porous carbon surface. The proposed method is also effective for glycoprotein multi-copper oxidase to fabricate high performance gas-diffusion biocathode.