Figure 4: (a) Current-voltage behaviour of fungal (squares, triangles) and tree (circles) laccase-based gas diffusion cathodes. Influence of oxygen on the polarisation curve obtained for fungal laccase in air (triangles) and oxygen (squares) stream conditions. (b) Tafel plots obtained from polarisation data for fungal (squares, triangles) and tree (circles) laccase. (c) The difference between potentials obtained in oxygen and air as a function of current density (from [4]).