Stable effect on MIL-101(Cr) with Cu2+for the toluene adsorption

Volatile organic compounds (VOCs) cause great harm to the ecological environment and human health. Metal -organic frameworks (MOFs) are one of the high-performance adsorbents for the removal of VOCs. A typical MOFs material MIL-101(Cr) was prepared by hydrothermal synthesis, and the properties of the material were optimized by doping copper ions. All prepared adsorbents were characterized by XRD, FTIR, SEM, TG and N2 adsorption-desorption. The results showed that Cu@MIL-101(Cr) with different Cu2+ doping content was suc-cessfully prepared without changing the framework structure of MIL-101(Cr). However, the surface area and pore size of Cu@MIL-101(Cr) were reduced, the crystallinity and thermal stability were influenced by varying degrees. Among the samples, Cu-2@MIL-101(Cr) expressed the best adsorption ability on toluene due to the introduction of unsaturated metal sites by doped copper ions, which could improve the adsorption performance of MIL-101(Cr), and its saturation adsorption capacity could reach 469 mg/g. Although Cu2+ doping reduced the spe-cific surface area of the material, the increased active sites could greatly improve the adsorption performance of the material, meanwhile the desorption efficiency of Cu-2@MIL-101(Cr) could also reach 86% after 5 times cycles.

Automated summary

Metal-organic frameworks (MOFs) are effective adsorbents for volatile organic compounds (VOCs) removal. The introduction of copper ions improves the adsorption capacity and thermal stability of the adsorbents.