Synthesis of N-TiO 2 /BiOI/RGO composites with significantly enhanced visible light photocatalytic activity
- PDF / 943,879 Bytes
- 9 Pages / 584.957 x 782.986 pts Page_size
- 78 Downloads / 204 Views
Synthesis of N-TiO2/BiOI/RGO composites with significantly enhanced visible light photocatalytic activity Limei Xue1,a), Fengzhi An1,b), Yanhao Yang2, Yuan Ma3 1
School of Environment and Chemical Engineering, Heilongjiang University of Science & Technology, Harbin 150022, China Suzhou Lai School Education Technology Co. Ltd., Jiangsu, Suzhou 215000, China 3 State Grid Xinyuan Compant Ltd., Jilin, Dunhua 133700, China a) Address all correspondence to these authors. e-mail: [email protected] b) e-mail: [email protected] Contributing Editor: Limei Xue 2
Received: 29 August 2019; accepted: 12 December 2019
In this work, four N-TiO2/bismuth oxyiodide (BiOI)/reduced graphene oxide (RGO) composite photocatalysts with different composite ratios were prepared using a hydrothermal method. The phase, surface structure, specific surface area, and light response were characterized by X-ray diffraction, X-ray photoelectron spectrum analysis, scanning electron microscopy, specific surface area and aperture analysis, and UV-vis diffuse reflection spectrum analysis. The results indicated that the N-TiO2/BiOI/RGO (NTGB) composite prepared with a mass ratio of 1:1:2 is a promising photocatalyst for the degradation of organic pollutants by using sunlight, with a specific surface area of 139.56 (m2/g), bandgap of 1.24 eV, and strong absorption with a smaller visible region. It has the best photocatalytic properties under visible light irradiation in the degradation of methylene blue (MB): the degradation rate of MB in the presence of light for 60 min reached 99.22%, and its photocatalytic performance was significantly higher than that of TiO2, N-TiO2, BiOI, N-TiO2/BiOI, BiOI/RGO, NTGB1, NTGB2, and NTGB4.
Introduction As environmental problems become more and more serious, it is important to find an efficient and eco-friendly way to govern the environment. Photocatalytic technology has attracted considerable attention from both academia and industry because it uses solar energy to degrade air and water pollutants with high efficiency and without causing pollution [1, 2, 3, 4]. Titanium dioxide (TiO2) is a kind of n-type semiconductor photocatalyst, and has received wide research interests owing to its advantages of non-toxic, cheap and stable physical and chemical properties. However, because of the large bandgap (about 3.2 eV) of TiO2, it can only be excited by ultraviolet light (represents 3–5% of the total sunlight energy), which limits its wide application [5, 6, 7, 8, 9]. To improve the efficiency of solar energy utilization, researchers have been working on photocatalytic materials that have the capability to respond to visible light (represents 43% of the total solar energy). Doping TiO2 with nonmetallic elements [10, 11, 12, 13] can form sublayers, reduce the bandgap width of TiO2, form traps in
ª Materials Research Society 2020
TiO2, reduce the recombination rate of photogenerated excitons (electron–hole pairs), and improve the photocatalytic activity. Fabricating a TiO2-based heterojunction structure using a narrow-bandgap semicon
Data Loading...
