H2V3O8 nanobelts as a novel stable electrode material with good reversible redox performance

Belt-like nanocrystalline H2V3O8 has been successfully synthesized via a hydrothermal process using vanadium pentoxide as inorganic precursor and 1,4-butanediol as structure-directing template. It is found that the reaction time has a significant effect on the morphology of the product. The as-synthesized H2V3O8 nanobelts are up to several of micrometers in length and about 35 nm in average width. The nanobelts show a large BET surface area which favors the electrochemical properties. The optical properties of the as-synthesized H2V3O8 nanobelts were investigated by UV-visible absorption and photoluminescence. The band gap was found to be 2.75 eV. Electrochemical measurements have revealed reversible redox behavior with doping/dedoping process corresponding to reversible cation intercalation/deintercalation. This process is easier in propylene carbonate than in aqueous solvent and is easier for the small Li+ to the larger Na+ one and to the largest K+ cation. This has been assigned to a probable presence of different tunnel cavities in the orthorhombic H2V3O8 lattice. (C) 2014 Elsevier B.V. All rights reserved.