Photocatalytic primary alcohol oxidation on WO nanoplatelets.

With the aid of direct heating through microwave irradiation in non-aqueous media, nanocrystalline tungsten(vi) oxide is achievable in 30 minutes at 200 °C, faster and at a lower temperature than conventional synthesis methods. Forming in a platelet morphology, these particles are as small as 20 nm with a BET surface area of 37 m g WO. These nanoplatelets are active for the photocatalytic oxidation of the 1° alcohols benzyl alcohol (rate constant, of 2.6 × 10 h) and 5-(hydroxymethyl)-2-furfural ( of 0.01 h) using 10 mg of WO with 2 mL of 0.250 M substrate in acetonitrile and a 150 mW cm 460 nm blue LED source. As expected, these rate constants are larger than those observed for commercially prepared, micron-sized WO. XPS analysis shows that during catalysis, the concentration of W on the surface increases, but the nanoplatelets are stable under these reaction conditions. The overall morphology and size of the particles are retained through the reactions. Moreover, the nanoplatelets are recyclable-showing no loss in activity for four reaction cycles.