Asphalt-Derived Carbon Nanostructures for Glucose/O2 Biofuel Cells

The electrode materials play extremely important roles in building the interfacial electron communications between the active sites of enzymes and the electrode surface, which significantly affect the performance of an enzymatic biofuel cell (EBFC). Herein, defective porous carbon is rationally designed and prepared using asphalt as the low-cost and high-carbon-yield precursor via a facile catalytic pyrolysis and NH3-etching process. The obtained defective asphalt-derived carbon (D-ADC) is utilized as the electrode material to immobilize enzymes and mediators in EBFC applications. It is found that the morphology and structure of ADC can be regulated by the catalytic pyrolysis and NH3-etching processes, which greatly increase the electroactive sites and specific surface area, thus enhancing the catalytic reaction kinetics. Specifically, the fabricated EBFC using D-ADC as the electrode material exhibits an open circuit voltage of 0.58 V and delivers a maximum output power density of 0.32 mW cm–2 with a short circuit current density of 1.12 mA cm–2, comparable to those using conventional graphene and carbon nanotubes. This work offers guidance for the design of functional carbon materials in the application of EBFCs, which has the potential to improve the sustainability and economic efficiency of waste asphalt.