Novel visible light-responsive graphene oxide/Bi₂WO₆/starch composite membrane for efficient degradation of ethylene

Graphene oxide/Bi₂WO₆ (GBW) photocatalyst was synthesized using a hydrothermal and surface deposition method. GBW/starch composite films with different graphene oxide (GO) additions (0, 0.25, 0.5, 0.75, 1 %) were prepared using a casting method. The GBW photocatalyst and composite starch film were characterized using X-ray diffractometry, X-ray photoelectron spectroscopy, Ultraviolet-visible diffuse reflectance spectroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, synchronous thermal analyzer, and the capacity of photocatalytic degradation of ethylene under visible light was evaluated. The results showed that GBW strengthens the mechanical properties, water vapor resistance and thermal stability of the composite film. Proper introduction of GO can refine lattice size, reduce bandgap and enhance visible light absorption. When the addition of GO was 0.5 %, GBW/starch composite film showed the strongest visible light degradation activity for ethylene, and the rate constant K' was 9.91 × 10^-4 min^-1, 4.4 times that of pure Bi₂WO₆. The composite film also had good recycling performance.