NOVELTY - Improvement of performance parameter of a microbial fuel cell (1300) comprises heating an electrode (1320) having an electrode surface to produce a heated electrode; and exposing the heated electrode to ammonia gas to produce a treated electrode having an increased positive surface charge on the electrode surface.    USE - The method is for improving performance parameter of a microbial fuel cell used to produce hydrogen and/or electricity. The microbial fuel cell is useful for wastewater treatment coupled to electricity or hydrogen generation, and renewable energy generation e.g. from non-waste products. It is used to power a device, such as a portable electronic device, and used in a remote device such as a marine sensor. The microbial fuel cell is a bio-electro-chemically assisted microbial reactor.    ADVANTAGE - The method provides a microbial fuel cell having an improved performance parameter (including increased maximum power density, increased coulombic efficiency, increased volumetric power density, and decreased microbial fuel cell operation time to achieve maximum power density), compared to a microbial fuel cell without the treated electrode.    DETAILED DESCRIPTION - Improvement of performance parameter of a microbial fuel cell comprises heating an electrode having an electrode surface to produce a heated electrode; exposing the heated electrode to ammonia gas to produce a treated electrode having an increased positive surface charge on the electrode surface; connecting the treated electrode and a cathode (1330) to produce an electrode assembly where treated electrode and cathode are in electrical communication; and disposing the electrode assembly at least partially in a reaction chamber (1302) containing a bioxidizable substrate for exoelectrogenic microorganisms and exoelectrogenic microorganisms. INDEPENDENT CLAIMS are included for:    (1) a microbial fuel cell; and    (2) a method of increasing positive surface charge on an electrode surface.    DESCRIPTION OF DRAWING(S) - The drawing is a schematic view of an electrode assembly for hydrogen generating microbial fuel cell including multiple brush anodes connected to multiple cylindrical cathodes.    Microbial fuel cell (1300)    Reaction chamber (1302)    Aqueous medium (1304)    Electrode (1320)    Cathode (1330)