A microbial fuel cell (MFC) is bioelectrochemical system that enables the biochemical activities of bacteria to generate electricity. A composite membrane was prepared from polyvinylidene fluoride nanofiber coated with perfluorinated sulfuric acid ionomer (PVDF-PFSA) and evaluated as a replacement for the commercially available Nafion membrane, which is commonly used in MFC reactors. The power density obtained with the PVDF-PFSA composite membrane was higher than that obtained with the Nafion membrane in MFC reactors. The PVDF-PFSA composite membrane produced a maximum power density of 548 mW/m². Hence, the PVDF-PFSA composite reported here is a promising candidate for use as a proton exchange membrane in energy devices and water treatment systems.