Photocatalytic activity of an Silicotungstic acid/PVA/PMMA composite nanofiber membrane

What is it about?

H4SiW12O40/polyvinyl alcohol (PVA) /Polymethylmethacrylate (PMMA) composite nanofiber membranes were prepared by electrospinning technique. PMMA emulsion was mixed with PVA and H4SiW12O40 evenly in water (electrospinning solvent). The configuration and element composition of the membranes were characterized by scanning electron microscopy (SEM), Fourier transformation infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The results indicated that H4SiW12O40 with intact Keggin structure existed in the composite membrane. The as-prepared H4SiW12O40/PVA/PMMA membranes exhibited enhanced photocatalytic efficiency (＞84%) in the degradation of methyl orange (MO), outperforming H4SiW12O40 powder (4.6%) and H4SiW12O40/PVA nanofiber membrane (75.2%) under ultraviolet irradiation. More importantly, H4SiW12O40/PVA/PMMA membranes could be easily separated from aqueous MO solution and the photocatalytic efficiency of the membranes decreased inappreciably after three photocatalytic cycles. It may be attributed to the enhanced water tolerance of the membranes and the stability of H4SiW12O40 in the membranes. The photocatalytic process was driven by the reductive pathway with much faster degradation rate owing to the presence of PVA.

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Why is it important?

H4SiW12O40/polyvinyl alcohol (PVA) /Polymethylmethacrylate (PMMA) composite nanofiber membranes were prepared by electrospinning technique. PMMA emulsion was mixed with PVA and H4SiW12O40 evenly in water (electrospinning solvent). The configuration and element composition of the membranes were characterized by scanning electron microscopy (SEM), Fourier transformation infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The results indicated that H4SiW12O40 with intact Keggin structure existed in the composite membrane. The as-prepared H4SiW12O40/PVA/PMMA membranes exhibited enhanced photocatalytic efficiency (＞84%) in the degradation of methyl orange (MO), outperforming H4SiW12O40 powder (4.6%) and H4SiW12O40/PVA nanofiber membrane (75.2%) under ultraviolet irradiation. More importantly, H4SiW12O40/PVA/PMMA membranes could be easily separated from aqueous MO solution and the photocatalytic efficiency of the membranes decreased inappreciably after three photocatalytic cycles. It may be attributed to the enhanced water tolerance of the membranes and the stability of H4SiW12O40 in the membranes. The photocatalytic process was driven by the reductive pathway with much faster degradation rate owing to the presence of PVA.