Abstract
Photocatalytic degradation of imidazolium ionic liquids using dye sensitized TiO2/SiO2composites
Huang, Lirong1; Yu, Yinghao1 Email author ; Fu, Chao2; Guo, Haiyang1; Li, Xuehui1
Source: RSC Advances, v 7, n 51, p 32120-32125, 2017; E-ISSN: 20462069; DOI: 10.1039/c7ra04939k; Publisher: Royal Society of Chemistry
Author affiliations:
1 School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou; 510641, China
2 SINTEF Energy Research, Trondheim; 7465, Norway
Abstract:
Ionic liquids (ILs) are widely applied in diverse fields, however, ILs bring considerable challenges to the ecosystem when exposed to the environment due to their cytotoxicity and high chemical stability. It is thus increasingly important to investigate measures for the degradation of IL wastes in industrial processes. This paper presents the preparation of dye-sensitized photocatalysts (DCQ-TiO2/SiO2) and their applications in the degradation of 4 imidazolium ILs (1-butyl-3-methylimidazolium bromide, [BMIM]Br; 1-butyl-3-methylimidazolium tetrafluoroborate, [BMIM]BF4; 1-butyl-3-methylimidazolium hexafluorophosphate, [BMIM]PF6; 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, [BMIM]NTf2). The photocatalysts are prepared through in situ incorporation of TiO2into silica matrices and sensitization with 2,9-dichloroquinacridone (DCQ). The photocatalysts are then characterized with N2adsorption-desorption isotherm measurements, transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), elemental analysis and ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS). The results show that these photocatalysts exhibit high catalytic activities when they are applied in the degradation of imidazolium ILs. The degradation efficiency for [BMIM]Br can reach up to 95% under simulated sunlight irradiation in 180 minutes. The photodegradation intermediates of [BMIM]+are identified as harmless and easily biodegradable moieties. © 2017 The Royal Society of Chemistry
