One-Step Synthesis of Submicrometer Fibers of MoO₃

Abstract

Nanorods of MoO 3 are accessible in gram quantities from MoO 3 ‚2H 2 O via a flexible onestep solvothermal reaction. Several hours of treatment in water at 180 °C are sufficient to convert the starting material quantitatively into rods with diameters around 100 nm and microscale lengths. The formation of MoO 3 rods proceeds in both neutral ionic and acidic media within a wide parameter window encompassing reaction temperatures between 90 and 180 °C and time scales ranging from several hours to 7 d. The rod morphology can be tuned by selecting a proper additive, and the nanorods withstand heating to 400 °C. Furthermore, the reaction pathways in various solvothermal media were investigated and both intermediate molybdic acids and the bulk nanorod products were characterized by means of EXAFS spectroscopy.

Systematic study on the influence of the morphology of α-MoO3 in the selective oxidation of propylene

“…Table 1). This is in agreement with literature [12], reporting that weak organic acids lead to particles of nanoscale diameter, whereas strong inorganic acids support the formation of rods in the microscale. The rod-like morphology (Figure 2b and d) and α-MoO3 phase could again be retained after calcination.…”

“…Especially selective oxidation reactions are known to be structure sensitive and thus strongly dependent on the shape [6][7][8][9]. Therefore the ability to control particle size, shape and composition of transition metal oxides has become an important research topic [10][11][12][13].…”

“…The method is, however, particularly attractive for (mixed) molybdenum oxides, which have high potential as catalysts in the selective oxidation of hydrocarbons [17][18][19][20][21][22]. Various preparation routes are known for the hydrothermal synthesis of molybdenum trioxide in the shape of ribbons, rods or nanobelts [12,[23][24][25][26][27][28].…”

“…These MoO3 nanomaterials tolerate temperatures up to 400 °C [12]. Furthermore, the crystal morphology can be altered by using different inorganic salts like NaNO3 and KNO3 in the synthesis solution [23,24].…”

Untersuchung der solvothermalen Bildung von MoO3‐Fasern mithilfe komplementärer In‐situ‐EXAFS/EDXRD‐Techniken

“…Wir haben daher vor kurzem eine einfach anzuwendende und handhabbare Solvothermalsynthese für MoO 3 -Fasern mit einem hohen Aspektverhältnis entwickelt. [14][15] Solvothermalreaktionen sind vielseitige Syntheseverfahren, die den jeweiligen präparativen Anforderungen angepasst werden können. [16] Dies wird insbesondere zur Steuerung der Partikelgröße bei der Synthese anorganischer Nanomaterialien genutzt.…”