Building 3D Architectures of VO₂·nH₂O Nanosheets Assembled with Ultrathin Nanobelts Decorated with Carbon Dots for Superior Zinc Storage

Three-dimensional porous architectures of VO 2 · n H 2 O curly nanosheets assembled with ultrathin nanobelts decorated with carbon dots (denoted as P-VO 2 · n H 2 O@C) are synthesized through a simple hydrothermal reduction of the V 2 O 5 –H 2 O 2 solution with 1,4-butynediol as the reducing agent and surfactant. Due to the crystal water and the enhanced conductivity derived from the decorated carbon dots, the ultrathin thickness (∼4 nm thick), and porous structure with densely distributed spaces among the nanosheets, the P-VO 2 · n H 2 O@C sample shows superior capability for zinc storage, a superior capacity of 231.6 mAh g –1, and a fine 88% capacity retention during 2000 cycles at a high current density of 10.0 A g –1, superior to those of the VO 2 nanobelts, which are only 110 mAh g –1 and 48% capacity retention under the same testing condition. Additionally, it affords an easy strategy to prepare curly nanosheets of VO 2 · n H 2 O or other similar metal oxides assembled with ultrathin nanobelts decorated with carbon.