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Rational design of the dimension and structure for electrode materials is an efficient strategy to boost the electrochemical properties. Herein, Fe2O3 nanoparticles are integrated with carbon substrates of different dimensions including a one-dimensional carbon nanotube (CNT), two-dimensional reduced graphene oxide (rGO), and a three-dimensional carbon framework composed of CNT and rGO via facile heterogeneous nucleation under hydrothermal conditions. These materials demonstrate a strong structure-dependent electrochemical performance. Among the three composites constructed, the rGO/CNT–Fe2O3 composite possesses an interconnected network with Fe2O3 uniformly distributed in the three-dimensional carbon skeleton composed of CNT and rGO. The two-dimensional conductive rGO could not only confine the Fe2O3 nanoparticles within the graphene layers to prevent the pulverization and agglomeration of Fe2O3 but also offer accessible active sites for the electrochemical reaction. The one-dimensional CNT interspersed within the interlayer space between the rGO nanosheet could impede the folding of the rGO sheet to enhance the ion/electron transport as well as maintain the multistructure of the composite during the charge and discharge process. Therefore, rGO/CNT–Fe2O3 can achieve a superior initial reversible capacity of 1306.9 mAh g–1 at 500 mA g–1 with a high capacity retention of 760.3 mAh g–1 after 400 cycles and a remarkable rate performance of 424.2 mAh g–1 at 5 A g–1. This work provides insight into the effect of carbon dimension on the energy storage capacity and develops an efficient strategy to construct multidimensional transition-metal oxide-based composites as anode materials for lithium-ion batteries.

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