An electrodeposited redox polymer-laccase composite film for highly efficient four-electron oxygen reduction

► Thin films of redox polymer-laccase composite are electrodeposited onto carbon electrodes under mild conditions. ► The deposited films catalyze the electroreduction of O2 at an operating potential of 0.58 V (vs. Ag/AgCl). ► The deposited films show excellent performance in terms of O2 electroreduction current density and stability.