Sucrose-templated Interconnected Meso/macro-porous 2D Symmetric Graphitic Carbon Networks As Supports for α-FeO Towards Improved Supercapacitive Behavior

In this study, ultrahigh electrochemical performance for interconnected meso/macro-porous 2D C@α-FeO synthesized sucrose-assisted microwave combustion is demonstrated. Hematite (α-FeO) synthesized the same approach gave an encouraging electrochemical performance close to its theoretical value, justifying its consideration as a potential supercapacitor electrode material; nonetheless, its specific capacitance was still low. The pore size distribution as well as the specific surface of bare α-FeO improved from 145 m g to 297.3 m g after it was coated with sucrose, which was endowed with ordered symmetric single-layer graphene (2D graphene). Accordingly, the optimized hematite material (2D C@α-FeO) showed a specific capacitance of 1876.7 F g at a current density of 1 A g and capacity retention of 95.9% after 4000 cycles. Moreover, the material exhibited an ultrahigh energy density of 93.8 W h kg at a power density of 150 W kg. The synergistic effect created by carbon-coating α-FeO resulted in modest electrochemical performance owing to extremely low charge transfer resistance at the electrode-electrolyte interface with many active sites for ionic reactions and efficient diffusion process. This 2D C@α-FeO electrode material has the capacity to develop into a cost-effective and stable electrode for future high-energy-capacity supercapacitors.