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a-MoO 3 nanobelts were successfully prepared by a facile hydrothermal method with sodium molybdate (Na 2 MoO 4 ) as the Mo source and NaCl as the capping agent. The as-prepared products were characterized using Fourier transformation infrared spectrophotometry (FT-IR), X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and selected area electronic diffraction (SAED) and their pseudocapacitive properties were investigated in a 0.5 M aqueous Li 2 SO 4 solution by cyclic voltammetry (CV), chronopotentiometry (CP) and AC impendence. The results show that the dimensions of the as-prepared a-MoO 3 nanobelts are 200-400 nm in width, ca. 60 nm in thickness and 3-8 mm in length. The redox potential for the a-MoO 3 nanobelts is found in the range of À0.3 to À1.0 V vs. SCE, which indicates that the a-MoO 3 nanobelts can be used as anode electrode materials for hybrid supercapacitors. The specific capacitances of the a-MoO 3 nanobelts at 0.1, 0.25, 0.5 and 1 A g À1 are 369, 326, 256 and 207 F g À1 , respectively. The maximum specific capacitance of the a-MoO 3 nanobelts is much higher than those of MoO 3 nanoplates with 280 F g À1 , MoO 3 nanowires with 110 F g À1 and MoO 3 nanorods with 30 F g À1 recently reported in literature. Furthermore, the a-MoO 3 nanobelt electrode exhibits a good cycle stability with more than 95% of the initial specific capacitance maintained after 500 cycles. Additionally, the present route to prepare nanostructured MoO 3 is much less expensive than those with Mo powders as the Mo source. Overall, the obtained high performance a-MoO 3 nanobelts could be a promising electrode material for supercapacitors.

Various transition metal oxide-based nanostructures with outstanding lithium-ion storage properties are considered as the most appealing candidates to substitute conventional carbonaceous anode materials in lithium-ion batteries. However, the rational design and tailored synthesis of hybrid materials with specific components, morphologies and structures are crucial to achieving superior electrochemical performances. In this paper, we have designed the synthesis of nanostructured anatase TiO 2 -modified iron oxides (Fe x O y ) on/among carbon nanotubes (CNTs) (denoted as TFCs) by a simple and inexpensive bottom-up assembly approach. In the as-designed TFCs, TiO 2 modifications include two forms: TiO 2coated on Fe x O y , and TiO 2 nanoparticles distributed among TFCs, which play a significant role in avoiding the aggregation and pulverization of the Fe x O y nanoparticles. With the introduced TiO 2 as a buffer material, and the CNTs framework as a porous 3D conducting/buffering network and an effective substrate for anchoring Fe x O y nanoparticles, as compared to all of the existing analogues reported, the as-designed TFCs display overwhelmingly superior Li + storage properties, to be specific, good capacity retention with 922 mAh g À1 at 500 mA g À1 and 1089 mAh g À1 at 200 mA g À1 , excellent rate capability with current densities varying from 50 mA g À1 to 10 A g À1 and remarkable cycling performance with the capacity increased from 584 to 922 mAh g À1 at 500 mA g À1 over 450 cycles (remaining stable at around 920 mAh g À1 after the 420th cycle) after the rate tests for the same tested cell. We believe that the fascinating TFCs as well as other hybrids with similar structures can be easily extended for diverse applications, such as supercapacitors and catalysts, thus exhibiting broad prospects in the design of high-performance hybrid materials.

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