Single-Crystalline Molybdenum Trioxide Nanoribbons: Photocatalytic, Photoconductive, and Electrochemical Properties

Large-scale, high-purity and uniform alpha-MoO3 nanoribbons have been synthesized by a facile hydrothermal route without employing surfactants or templates. The as-prepared alpha-MoO3 nanoribbons were up to several micrometers in length, 100 nm in width, 15-20 nm in thickness, and grew along the [001] direction. The obtained nanoribbons exhibited a quantum size effect in optical properties, showing a blue shift of the band gap and direct transitions compared with the values of bulk MoO3. The nanoribbons also showed superior photocatalytic ability in the photodegradation reaction of an aqueous solution of Rhodamine B under visible light. Furthermore, the as-prepared alpha-MoO3 materials exhibited linear current-voltage (I-V) characteristics and excellent photoresponse. As the light source was switched on and off, the currents could be reversibly switched between high and low value at the voltage of 0.1 V. Electrochemical measurements predicted that the alpha-MoO3/carbon fiber modified microelectrode would display excellent electrochemical characters and high sensitivity toward neurotransmitter dopamine. The modified electrode was also quite stable and had good reproducibility, which might have application in the electrochemical analysis.