Graphene oxide (GO) is an emerging material for energy, environmental, and many other applications which in the past has been produced using chemical processes involving high-energy consumption and hazardous chemicals. Embodiments of the present invention focus on bioelectrochemical systems (BES) having microorganism(s), an anode (11) and cathode (14) to produce GO (13) from graphite, coal, and other carbonaceous materials under ambient conditions without chemical amendments. In some embodiments, value-added organic compounds (17) and even H2 (16) can be produced.