A UiO-66 3D photonic crystal optical sensor for highly efficient chlorobenzene vapor detection

Chlorobenzene (C₆H₅Cl) is a flammable liquid with high vapor activity, which is a severe threat to the environment and human health. Therefore, it is essential to develop a highly efficient sensor to detect C₆H₅Cl vapor. Herein, we developed a UiO-66 three-dimensional photonic crystal (3D PC) optical sensor and investigated its sensing properties toward the C₆H₅Cl vapor. The UiO-66 3D PCs optical sensor shows a high sensitivity of C₆H₅Cl vapor, in the concentrations range of 0-500 ppm, the reflectance intensity response to be 0.06% ppm with a good linear relationship, detection limit can reach 1.64 ppm and the quality factor is 10.8. Additionally, the UiO-66 3D PC optical sensor demonstrated great selectivity with the values of selectivity (S) varying from 2.24 to 10.65 for the C₆H₅Cl vapor as compared with carbon tetrachloride (CCl₄), dichloromethane (CH₂Cl₂), 1,1,2-trichloroethane (C₂H₃Cl₃), benzene (C₆H₆), deionized water (H₂O), ethanol (C₂H₅OH) and methyl alcohol (CH₃OH) vapors. Moreover, the UiO-66 3D PC optical sensor shows an ultrafast optical response time and recovery times of 0.5 s and 0.45 s with exceptional stability and repeatability to 500 ppm C₆H₅Cl vapor. These excellent sensing properties are attributed to the efficacy of signal transduction, increased porosity and gas adsorption sites, which are intrinsically endowed by the design of the 3D optical structure. The design and fabrication of this UiO-66 3D PC optical sensor might open up potential applications for the detection of the C₆H₅Cl vapor.