Facile Synthesis of Mesoporous α-Fe(2)O(3)@g-C(3)N(4)-NCs for Efficient Bifunctional Electro-catalytic Activity (OER/ORR)

Mesoporous α-iron oxide@graphitized-carbon nitride nanocomposites (α-Fe(2)O(3)@g-C(3)N(4)-NCs) were synthesized using urea-formaldehyde (UF) resins at 400 °C/2 h. The mesoporous nature of the prepared nanocomposites was observed from electron microscopy and surface area measurements. The electrochemical measurements show the bifunctional nature of mesoporous α-Fe(2)O(3)@g-C(3)N(4)-NCs in electrolysis of water for oxygen evolution and oxygen reduction reactions (OER/ORR) using 0.5 M KOH. Higher current density of mesoporous α-Fe(2)O(3)@g-C(3)N(4)-NCs reveals the enhanced electrochemical performance compared to pure Fe(2)O(3) nanoparticles (NPs). The onset potential, over-potential and Tafel slopes of mesoporous α-Fe(2)O(3)@g-C(3)N(4)-NCs were found lower than that of pure α-Fe(2)O(3)-NPs. Rotating disc electrode experiments followed by the K-L equation were used to investigate 4e(−) redox system. Therefore, the mesoporous α-Fe(2)O(3)@g-C(3)N(4)-NCs bifunctional electro-catalysts can be considered as potential future low-cost alternatives for Pt/C catalysts, which are currently used in fuel cells.