Single-step fabrication of surface morphology tuned iron oxide anchored highly porous carbon nanotube hybrid foam for a highly stable supercapacitor electrode.

The pseudocapacitive metal oxide anchored nanocarbon-based three-dimensional (3D) materials are considered attractive electrode materials for high-performance supercapacitor applications. However, the complex multistep synthesis approaches raise production costs and act as a major barrier to the practical real-world field. To overcome this limitation, in this study, an easily scalable and effective fabrication approach for the development of iron oxide (FeO) anchored highly porous carbon nanotube hybrid foam (f-FeO/O-CNTF) with micro/mesoporous structure was suggested to improve the durability and energy storage performance. The surface morphology-tuned f-FeO/O-CNTF (f-FeO/O-CNTF(M)) was fabricated through electromagnetic interaction between the anchored magnetic FeO on the CNT surface and the applied magnetic field. The obtained results clearly demonstrated that the changed surface morphology of the f-FeO/O-CNTF(M) strongly affected the meso- and micropore structure, electrochemical performance, and durability. Consequently, the f-FeO/O-CNTF(M) showed an almost 120% enhanced specific surface area and nearly 1.9 times increased specific capacitance compared to that of the f-FeO/O-CNTF. Furthermore, the changed surface morphology successfully prevented the re-aggregation of the initial structure and significantly improved durability. As a result, f-FeO/O-CNTF(M) showed outstanding cycling stability, maintaining almost 100% capacitance retention after 14,000 cycles. Consequently, the assembled symmetric supercapacitor device delivered an energy density of 20.1 Wh·kg at a power density of 0.37 kW·kg with good cycling stability. These results suggest that the f-FeO/O-CNTF(M) can potentially be used as an electrode for supercapacitors with good durability.