Transition-metal oxide hollow yolk-shell micro/nanostructures combined with a conducting substance have gained significant attention as efficient electrode materials for electrochemical energy storage applications due to their large surface area, internal void space, and structural stability. Herein, we report a facile aqueous solution-based soft template method using sucrose-CTAB for the synthesis of a hollow yolk-shell structure of carbon-incorporated MoO2 (C@MoO2) with a diameter of 0.9-1.1 μm, wall thickness of 100 nm, inner yolk size of 400-450 nm, and BET surface area of 40 m2 g-1. During the synthesis process, sucrose plays a dual role, both as a template and a carbon source. The electrochemical charge storage mechanism follows a battery-type behaviour when tested as a faradaic electrode in 3.0 M KOH electrolyte. C@MoO2 exhibits a high specific capacity of 188 C g-1 at the current density of 0.5 A g-1, good rate performance (50.6 C g-1 at 10 A g-1), and 78% retention of capacity after 5000 cycles at 5 A g-1. The obtained performance is superior to those obtained for pure MoO2 hollow spheres (137.1 C g-1 at 0.5 A g-1) as well as previously reported MoO2 and MoO3, indicating the potential applicability of the as-synthesised yolk-shell C@MoO2.
Bibliographical noteFunding Information:
CSIR-CSMCRI communication No. 039/2017. The authors would like to acknowledge SERB, India (EMR/2014/001219) for financial support. A. Saha and S. Maiti acknowledge the UGC and CSIR, India, respectively, for their fellowships. The authors also acknowledge the ‘‘ADCIF’’ of CSMCRI for providing instrumentation facilities.
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