Rapid Synthesis And Characterization Of Micro And Nanostructures Of Molybdenum Trioxide

Micro - and nanostructures of molybdenum trioxide (MoO3) have been investigated intensively for sensorial and electrochromic systems. MoO 3 nanostructures were grown by a rapid thermal oxidation of molybdenum at 1000°C in oxygen environment. Its structural, morphological and optical properties were studied using scanning electron microscopy (SEM), X-ray diffraction (XRD), micro-Raman and optical transmission techniques. This work presents a new technique for facile synthesis of MoO3 nanostructures via thermal oxidation, and the results of exploration of their properties. MoO3 is found to consist of stratified long micro/nano-ribbons and nanowires promising for applications in sensor and other device structures. © 2013 IEEE

Versatile Growth of Freestanding Orthorhombic α‑Molybdenum Trioxide Nano- and Microstructures by Rapid Thermal Processing for Gas Nanosensors

We demonstrate a new technique that requires a relatively low temperature of 670–800 °C to synthesize in 10–20 min high crystalline quality MoO₃ nano- and microbelts and ribbons. The developed technological process allows rapid synthesis of large amounts of MoO₃ nano- and microsheets, belts, and ribbons, and it can be easily scaled up for various applications. Scanning electron microscopy (SEM) studies revealed that the MoO₃ nano- and microbelts and ribbons are synthesized uniformly, and the thickness is observed to vary from 20 to 1000 nm. The detailed structural and vibrational studies on grown structures confirmed an excellent agreement with the standard data for orthorhombic α-MoO₃. Also, such freestanding nano- and microstructures can be transferred to different substrates and dispersed individually. Using focused ion beam SEM, MoO₃-based 2D nano- and microsensors have been integrated on a chip and investigated in detail. The nanosensor structures based on MoO₃ nano- and microribbons are quite stable and moderately reversible with respect to rises and drops in ethanol vapors. It was found that MoO₃ nano- and microribbons of various sizes exhibit different sensitivity and selectivity with respect to ethanol, methanol, and hydrogen gases. The developed technique has great potential for further studies of different metal oxides, nano- and microsensor fabrication, and especially for multifunctional applications