A decrease in CO2 solubility was also observed in the neat ionic liquid [BMIM][NTf2] upon UV irradiation (63 µmol/gL, ambient; 50 µmol/gL, UV irradiation). Since the temperature in the photoreactor remained constant during the sorption measurements, it is unlikely that this was the cause of decrease in CO2 solubility. To our knowledge, there are few studies investigating the effects of UV irradiation on ionic liquids. However, a report by Rao et al. notes changes in the UV-vis and fluorescence spectra on a similar ionic liquid, [BMIM][BF4], but concludes that there is very little change in the bulk of the material. For [BMIM][NTf2], changes are observed in the UV-vis spectra on irradiation (Figure ), which may be responsible for the observed changes in gas solubility, but no structural changes were observed in the 1 H NMR spectra (Figure ). In addition, the difference in CO2 uptake upon irradiation in the ionic liquid (13 µmol/gL) was lower than for the porous liquids at higher MOF loadings (12.5 wt. %, 23 µmol/gPL, 20 wt. %, 29 µmol/gPL), confirming an additional contribution from the incorporated MOF.