Micelle-Directing Synthesis of Ag-Doped WO3 and MoO3 Composites for Photocatalytic Water Oxidation and Organic-Dye Adsorption.

In this paper, an Ag-doped WO3 (and MoO3 ) composite has been prepared by following a simple micelle-directed method and high-temperature sintering route. The as-prepared samples were characterized by X-ray diffraction, inductively coupled plasma, transmission electron microscopy, X-ray photoelectron spectroscopy, UV/Vis diffuse reflectance spectroscopy, Brunauer-Emmett-Teller, photoluminescence spectroscopy, and electrochemical impedance spectroscopy techniques. The photocatalytic experiments reveal that their oxygen-production rates are up to 95.43 μmol (75.45 μmol) for Ag-doped WO3 (MoO3 ), which is 9.5 (7.3) times higher than that of pure WO3 : 9.012 μmol (MoO3 : 9.00 μmol) under visible-light illumination (λ≥420 nm), respectively. The improvement of their photocatalytic activity is attributed to the enhancement of their visible-light absorption and the separation efficiency of photogenerated carriers by Ag doping. Moreover, Ag-doped WO3 (MoO3 ) also shows excellent adsorption of rhodamine B (RhB) and methylene blue (MB) in aqueous solution, with maximum adsorption capacities towards RhB and MB of 822 and 820 mg g-1 for Ag-doped WO3 , and 642 and 805 mg g-1 for Ag-doped MoO3 , respectively.