CuO/Bi2O3/g-C3N4 nanoparticles for sunlight-mediated degradation of polyethylene terephthalate microplastic films

Abstract

A novel photodegradable CuO/Bi2O3/g-C3N4(copper oxide/bismuth oxide/graphitic carbon nitride) nanoparticle (NP) was synthesised using the sol-gel method and sunlight-mediated degradation of polyethylene terephthalate (PET) microplastics (MPs) films. The optical and structural properties of the sol-gel method were investigated using a variety of characterization methods, like UV–vis diffuse reflectance spectroscopy (UV–vis DRS), Fourier transform infrared (FT-IR), X-ray diffractometer (XRD) analysis, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis. Degradation study results suggest that the photocatalytic activity of CuO/Bi2O3/g-C3N4/PET nanocomposites (NCs) films was greater than that of pure PET, CuO/PET, Bi2O3/PET, g-C3N4/PET, CuO/g-C3N4, Bi2O3/g-C3N4, and CuO/Bi2O3/PET films. Because of their increased optical absorption and efficient suppression of photo-produced charge carriers’ recombination, the CuO/Bi2O3/g-C3N4/PET NCs films showed higher photocatalytic degradation than PET films. Thus, PET films with CuO/Bi2O3/g-C3N4 (5:5:2 % wt) NPs showed a degradation of around 41.60 % among pure PET, CuO/PET, Bi2O3/PET, g-C3N4/PET, CuO/g-C3N4/PET, Bi2O3/g-C3N4/PET, and CuO/Bi2O3/PET NCs films under visible light over a short period of 30 days (240 h). When compared to the original PET MPs, the CuO/Bi2O3/g-C3N4/PET NCs films showed a significant decrease in crystallinity and carbonyl indexes, as much as 29.2 % lower. The present research also suggests a photocatalytic mechanism, which may explain the increased photocatalytic activity.