2D single- or double-layered vanadium oxide nanosheet assembled 3D microflowers: Controlled synthesis, growth mechanism, and applications

A facile one-pot solvent-thermal method was developed to synthesize a unique 3D microflower structure assembled from single- or double-layered 2D nanosheets of V₄O₉ (F-VO). Simply by controlling the precursor concentration, yolk-shelled V₄O₉ (YS-VO) or bulk V₄O₉ (B-VO) can be produced instead. The precursor-concentration dependent growth mechanism is proposed. The exceptional catalytic/electrochemical properties and large specific surface area of F-VO promise a wide range of applications. As a proof-of-concept demonstration, we investigate its use in high-performance supercapacitors (∼392 F g ^-1), and for sensitive detection of H₂O₂ (with a low detection limit of ∼0.1 μM) and methanol (with a low detection limit of ∼60 μM). Furthermore, we show that F-VO greatly outperforms its counterparts (YS-VO and B-VO) presumably owing to its unique structure and crystal plane orientation.