کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6466770 | 1422968 | 2017 | 10 صفحه PDF | دانلود رایگان |
- Visible light active g-C3N4/TiO2 composites employed for NO oxidation.
- Determination of CB edge of the composites by Mott-Schottky relation.
- Tuning of composites' band gap and CV edge by variation of components' weight ratio.
- Superior NO oxidation by 1:4 composite than pure g-C3N4 and TiO2 components.
Graphitic carbon nitride/titania (g-C3N4/TiO2) composite photocatalysts with different C3N4/TiO2 ratios were synthesised by a simple preparation route through annealing the mixtures of melamine and commercial TiO2 P25 powder at 550 °C for 3 h under Ar flow. The resulting composite photocatalysts were characterized by X-ray diffraction, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, UV-visible diffuse reflectance spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and electrochemical impedance spectroscopy. The photocatalytic activity of the composites was evaluated using NO as a target inorganic air pollutant. Variation of the initial weight ratio of melamine precursor/TiO2 (3:1, 1:1, 2:3, 1:3, 1:4 and 1:7) allowed tuning of the composites' band gap from 2.66 eV in pure g-C3N4 to 3.14 eV in pure P25 as revealed by UV-visible spectroscopy. The conduction band edges position determined by electrochemical measurements using Mott-Schottky relation varied from â¼â1.27 eV in pure g-C3N4 to â¼â0.67 eV in pure P25 (vs NHE, pH 7). Under visible light, the g-C3N4/TiO2 composite with initial ratio 1:4 exhibited superior photocatalytic activity in NO oxidation in comparison to the pure semiconductors g-C3N4 and TiO2. This finding was explained to be a result of a combination of the optical and electronic properties of the composites.
Journal: Chemical Engineering Journal - Volume 310, Part 2, 15 February 2017, Pages 571-580