Facile microbial fuel cell from pencil utilizing sustainable cathode as of used battery

In our work, we proposed the novel simplified pencilbased integrated microbial fuel cells (P-MFCs). In a pencil, the graphite rod could act as anode with a wooden portion submerged into the raw wastewater solution, whereas the remained wooden portion is exposed to air and bound with carbon cloth containing the Pt electrocatalysts for oxygen reduction reaction. P-MFC showed a volumetric power density of 3.61 mW m^-3 and current density of 9 mA m^-3 at 0.403 V. Further, the pencil was treated with sulphuric acid solution and exhibited the lignosulfonate peaks at 1032 cm^-1 and 872 cm^-1 in the FT-IR spectroscopy. Later, 6M sulfuric acid-treated pencil standard cell exhibited a volumetric power density of 956 mW m^-3 (as standard P-MFCs) Then, we took the cathode of an alkaline battery to be used as cathode for PMFCs. Interestingly, this arrangement exhibit a volumetric power density of 936.12 mW m^-3. Finally, we developed a prototype for powering a digital clock. Thus, we avoided using noble metal catalyst and our simplified MFC design greatly decreased the cost.