Facile synthesis and modification of Fe2O3 nanorod arrays on carbon paper as efficient negative electrodes for supercapacitors.

In this research, Fe 2 O 3 nanorod arrays grown on carbon fiber paper were studied, and carbon-coated Fe 2 O 3 (Fe 2 O 3 @C) and sulfurized Fe 2 O 3 @C (Fe 2 O 3 @C-S) were fabricated by carbon coating and sulfurization processes. To promote the application of these materials in supercapacitors, their electrochemical properties were systematically investigated. Based on the results, the materials obtained utilized a pseudocapacitive mechanism for energy storage. Specifically, Fe 2 O 3 exhibited a moderate specific capacitance and extraordinary cycling stability, and no degradation was observed after 10,000 cycles. Impressively, sulfurization greatly enhanced the rate capability and specific capacitance of the sample. As a result, Fe 2 O 3 @C-S attained a specific capacitance of 976.4 mF cm–2 at 4 mA cm–2 and a robust rate capability of 97.30% at 20 mA cm–2, outperforming Fe 2 O 3 @C (84.39%) and Fe 2 O 3 (70.55%) and demonstrating good cycling stability (92.9%). Notably, Fe 2 O 3 @C-S was active as a positive electrode material; thus, a symmetric supercapacitor was assembled, which yielded a volumetric energy density of 1.46 mWh cm–3 at 16.71 mW cm–3 and maintained an energy density of 0.91 mWh cm–3 even at 145.63 mW cm–3. Moreover, the device exhibited good cycling stability with a capacity retention of 88.3% after 10,000 cycles at 10 mA cm–2. The integration of Fe 2 O 3 nanorod arrays on conductive substrates, coupled with the above modifications, strongly promoted the material's energy storage performance. Our study emphasized the significant potential of Fe 2 O 3 @C-S as an efficient electrode material for supercapacitors. • Fe 2 O 3 /CFP exhibited outstanding cycling stability with no capacity degradation. • Fe 2 O 3 @C-S showed greatly enhanced specific capacitance and rate capability. • Pore structure demonstrated a crucial factor in determining the performance. [ABSTRACT FROM AUTHOR]