Visible-light photocatalytic denitrogenation of nitrogen-containing compound in petroleum by metastable Bi20TiO32

Exploration of new system which selectively removes nitrogen-containing organic compounds in petroleum by photocatalytic catalysts is of great value on enriching the foundation of photocatalytic science as well as developing photocatalytic technologies in their practical applications in gasoline fuel. In this paper, tetrabutyl titanate was used as titanium source and bismuth nitrate was utilized as the source of bismuth, and Bi20TiO32 was synthesized using ultrasonic assisted impregnation method. The samples were characterized by X-ray diffraction (XRD), N2 adsorption–desorption (BET), and X-ray photoelectron spectroscopy (XPS). To evaluate its photocatalytic denitrogenation performance, simulated gasoline feed containing a certain concentration of pyridine was used as a reference. The analysis results showed that the synthesized Bi20TiO32 was a type of tetragonal crystal system of Bi–Ti oxide in metastable phase with nanosheet at a size of about 15 nm and band gap of 2.9 eV. This system can absorb the light ranging from UV to 500 nm wavelength. Under the irradiation of visible light above 420 nm wavelength for 150 min, the conversion of pyridine by photocatalytic degradation in 50 mL simulated feed (pyridine containing 100 μg/g) using 0.05 mg the photocatalyst was up to 86.0%. The visible light removal efficiency of pyridine was directly proportional with the illumination time, and there was no noticeable oxidation degradation of the solvent.