Hexagram-shaped V₂O₃ Nanoparticles: Synthesis and Characterization

Hexagram-shaped V₂O₃ nanoparticles were synthesized by annealing hexagram-shaped NH₄V₃(OH)₆(SO₄)₂ precursor prepared through hydrothermal method.Both the precursor and annealed samples were characterized,and the formation mechanism of hexagram-shaped nanostructure NH₄V₃(OH)₆(SO₄)₂ was investigated by SEM characterization at different periods during the reaction.The results show that the dimensions of precursor particles are about 600 nm in axial direction,more than 200 nm for each branch and less than 100 nm in the width,respectively.After annealing,the dimensions of V₂O₃ particles are below 300 nm in axial direction and about 100 nm for each branch and no more than 50 nm in the width,respectively.Electrochemical measurements show that the discharge specific capacity of hexagram-shaped V₂O₃ reaches 77 mAh/g at a current density of 50 mAh/g with the cutoff voltage range 3.0~1.5 V,and remains at 42 mAh/g after 20 cycles.