Hydrothermal preparation of Au-doped Bi<inf>2</inf>WO<inf>6</inf> nanoplates for enhanced visible-light-driven photocatalytic degradation of rhodamine B

Abstract

Undoped Bi2WO6 and Au-doped Bi2WO6 nanoplates were prepared via a simple hydrothermal method. The physical and chemical properties of the as-synthesized undoped Bi2WO6 and Au-doped Bi2WO6 samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectrophotometry, UV–visible spectroscopy and photoluminescence (PL) spectroscopy. The analytical results showed that the undoped Bi2WO6 and Au-doped Bi2WO6 samples were orthorhombic Bi2WO6 nanoplates with no detection of other phases. The oxidation state of Au ions was +3 and successfully incorporated in Bi2WO6 lattice. The photocatalytic activities of the nanoplates were investigated through the degradation of rhodamine B (RhB) under visible light irradiation. In this research, 3% Au-doped Bi2WO6 nanoplates have the lowest emission intensity and good absorption in the UV–visible region with the absorption edge of 437 nm. They also have the highest RhB degradation of 96.25% under visible light irradiation within 240 min and were 2.15 times of pure Bi2WO6 nanoplates.