Amylose-halloysite-TiO2 composites: Preparation, characterization and photodegradation

A supramolecular structure was initially formed between amylose and halloysite (HNT) simply by using a mechanical force. Subsequently, amylose acted as a template for the growth of TiO2 nanoparticles. The thus-prepared amylose-HNT-TiO2 composite was characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analyses, and transmission electron microscopy (TEM). In comparison to its counterpart HNT-TiO2 composite, the amylose-HNT-TiO2 composite exhibited better dispersion, a larger specific surface area, and photocatalytic activity that was more effective for the photodegradation/removal of methylene blue (MB) and the persistent organic pollutant 4-nitrophenol (4-NP) under UV irradiation. After four successive UV irradiation treatments, amylose-HNT-TiO2 removed about 90% of 4-NP or MB.