Synthesis of N-doped carbon nanosheets from collagen for electrochemical energy storage/conversion systems

This study proposes a simple method for synthesizing carbon nanosheets doped with nitrogen through carbonization of collagen. Collagen, the most abundant protein in mammals, was cross-linked with paraformaldehyde and subsequently heated in vacuum at 800 °C to obtain N-doped carbon nanosheets with a high specific surface area of 695 m2 g−1. With the contribution of N-doped structures, the carbon nanosheets show ideal capacitive behavior with 80% capacitance retention in 0.5 M H2SO4 at 1000 mV s−1. In comparison with a commercial electrocatalyst, 20% Pt on Vulcan XC-72, carbon nanosheets display a positive shift in the onset potential and superior electrocatalytic activity toward the oxygen reduction reaction (ORR). The above excellent electrochemical performances render the N-doped carbon nanosheets a promising material for electrochemical energy storage/conversion systems.