Photocatalytic Degradation of Methylene Blue and Methyl Orange over TiO<sub>2</sub> Powder Synthesized via the Solvothermal Method

Titanium dioxide (TiO 2 ) powder was synthesized via the solvothermal method. Titanium isopropoxide (C 12 H 28 O 4 Ti), ammonium hydroxide (NH 4 OH) and nitric acid (HNO 3 ) were used as the starting materials. The mixed solution was diluted with ethanol (C 2 H 5 OH) and heated at 100°C for 5h in a Teflon–lined stainless steel autoclave vessel. The phase transition of TiO 2 powder was studied by X–ray diffraction (XRD). The morphology and chemical composition of TiO 2 powder were investigated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The photocatalytic degradation of methylene blue and methyl orange over TiO 2 powder were determined using Ultraviolet–visible spectroscopy (UV–Vis).