Electrical performance of low cost cathodes prepared by plasma sputtering deposition in microbial fuel cells

► The island structure obtained by sputtering may favor metal catalytic activity. ► The abundant cracks and pores in the cathode structure may improve gas diffusion. ► Sputtered cathodes generated competitive power with a catalyst load 5 times lower. ► Pt-ink (+ control) > Sputtered-Pt = Sputtered-Co> No metal (− control). ► Signs of biocatalysis activity on metal-free cathodes were observed.