In Situ Fabrication of Nitrogen Co-Doped Carbon Materials from Biomolecule Guanine for Enhanced Oxygen Electrocatalysis

Metal-nitrogen co-doped composite (M-N-C) carbon materials exhibit outstanding catalytic performance in oxygen reduction reactions (ORR), making them promising candidates to replace commercial Pt/C catalysts. However, it remains a challenge to achieve a rational design that ensures a uniform dispersion of the metal active centers in the nitrogen-doped carbon materials and an effective construction of the M-N active sites to enhance the ORR performance. This research introduces an innovative in situ pyrolysis technique utilizing the guanine biomolecule in conjunction with ZIF-67. This approach not only circumvents the pitfalls of structural disintegration and cobalt center agglomeration but also creates an abundance of anchoring sites conducive to the atomic dispersion of cobalt. Consequently, this method fosters the synthesis of Co-N and pyridinic-N active sites, which are pivotal for catalytic activity. The G-Co@NC-800 catalyst demonstrates exceptional ORR catalytic prowess, with a half-wave potential of 0.83 V (vs RHE) and a current density of −5.1 mA·cm −2 , coupled with remarkable stability and methanol tolerance in alkaline media. These attributes surpass those of commercial Pt/C catalysts, underscoring the superiority of this novel catalyst. This pioneering approach promotes the rational design of uniformly dispersed Co nanoparticles and the extensive construction of Co-N sites.