Functionalization-Mediated Preparation via Acid Precipitation and Photocatalytic Activity of In Situ Ag₂WO₄@WO₃.H₂O Nanoplates

Abstract

Tungsten oxide hydrate (WO3.H2O) nanoplates were in situ functionalized with AgNO3 via a one-step acid precipitation method at room temperature. The functionalized product was the nanocomposite of Ag2WO4 and WO3.H2O. Both pristine and functionalized samples had nanoplate morphology. The nanoplates’ dimension and uniformity decreased with the increase in the AgNO3 amount, resulting in increased specific surface area. The AgNO3 functionalization supported a growth via the orthorhombic WO3.H2O structure, caused a change in the dominant facet from (020) to (111), lessened the micro-strain, and enhanced the photocatalytic activity of samples under visible-light irradiation (λ ≥ 450 nm). The samples functionalized with 5 mass % of AgNO3 showed the highest methylene blue degradation efficiency of 49% and a degradation rate of 0.122 mg g−1 × min, which could be assigned to the largest specific surface area and the synergistic effect caused by the Ag2WO4@WO3.H2O junction. These results suggested a simple method for tailoring the dominant facet and morphology of WO3.H2O-based materials for visible-light-driven applications.

Temperature-mediated Phase Transformation and Optical Properties of Tungsten Oxide Nanostructures Prepared by Facile Hydrothermal Method

“…Notably, all observed optical band gap values are in the visible range. The moderate optical band gap value of samples RT, T100, T120, and T150 (∼ 2.40 eV) was assigned to the orthorhombic WO 3 •H 2 O structure which took the main part in these samples [41][42][43][44]. The large optical band gap of ∼ 2.70 eV of samples T200 and T220 was assigned to the monoclinic WO 3 which is similar to the values reported elsewhere [18,[45][46][47].…”

Ag-Doped WO3 Nanoplates as Heterogenous Multifunctional Catalyst for Glycerol Acetylation, Electrocatalytic and Enhanced Photocatalytic Hydrogen Production

“…The introduction of impurities or additives can alter the ultimate shape of the crystal by tuning the growth rate and orientation of the crystals. 9 To analyze the elemental composition, energydispersive X-ray (EDAX) studies were also performed along with FESEM. Figure S1(a− 5, and 5% Ag-doped WO 3 nanoplates with an average particle size of 54, 100, and 110 nm.…”

“…5 Tungsten oxide (WO 3 ) has a wide band gap in the range of 2.6−3.0 eV, and it is an n-type semiconductor material. 6 Varied approaches have been employed for the synthesis of tungsten oxide nanoparticles, namely, hydrothermal or solvothermal, 7,8 acid precipitation, 9 sonochemical, 10 chemical vapor deposition, 11 combustion, 12 and reverse micellar method. 13 Varied synthesis approaches produce materials with definite characteristics including crystal structure, elemental composition, and surface morphologies.…”

“…Nowadays, researchers are showing intense focus on synthetic approaches for generating nanostructures with well-defined morphologies; meanwhile, hydrothermal method has been widely employed for WO 3 -based nanoplates, 14 nanorods, 15 nanowires, 16 nanoflakes, 17 and hierarchical nanostructures 18 due to their fascinating semiconducting, optical, catalytic, and photocatalytic applications. 9,16,19,20 The hydrothermal method of synthesis involves heating of metal coordination compounds and solvents with or without organic capping agents at high temperatures. 21 Transition metal oxides doped or decorated with noble and rare earth metals is an efficient method to enhance the performance of materials.…”

“…Varied synthesis approaches produce materials with definite characteristics including crystal structure, elemental composition, and surface morphologies. Nowadays, researchers are showing intense focus on synthetic approaches for generating nanostructures with well-defined morphologies; meanwhile, hydrothermal method has been widely employed for WO 3 -based nanoplates, nanorods, nanowires, nanoflakes, and hierarchical nanostructures due to their fascinating semiconducting, optical, catalytic, and photocatalytic applications. ,,, The hydrothermal method of synthesis involves heating of metal coordination compounds and solvents with or without organic capping agents at high temperatures …”