A method of surface treating a separator plate of a fuel cell comprises reacting the separator plate with an aqueous solution of hydrogen peroxide. The aqueous solution of hydrogen peroxide comprises one or more salts of one or more transition metals. The one or more transition metals have variable oxidation states. This method makes the surface of the separator plate hydrophilic (˜35 deg contact angle of water) and improves its electrical conductivity. The method of surface treating a separator plate (e.g., a graphite and/or graphite composite plate) of a fuel cell can further comprise a method of modifying wettability of the separator plate comprising treating the separator plate with a solution comprising one or more silanes. In another embodiment, a method of modifying wettability of a separator plate (e.g., a stainless steel separator plate) of a fuel cell comprises treating the separator plate with a solution comprising one or more silanes without a surface treating step prior to treating the separator plate with the solution comprising one or more silanes.