A novel and universal metal-organic frameworks sensing platform for selective detection and efficient removal of heavy metal ions

Pollution generated by heavy metals has become a global environmental issue with much public concern. For the first time, the current research presented series of amino-decorated MOFs as a universal sensing platform that demonstrated great potential for detecting and removing heavy metals with remarkable specificity and capability. Concretely, the amino-functionalized MIL-101(Fe) synthesized via a simple one-step method possessed satisfactory fluorescence due to the linker emission, and the excellent sensing performance of MIL-101-NH2 in detecting Fe3+, Cu2+ and Pb2+ with a low LOD and a broad liner range could be achieved. Furthermore, MIL-101-NH2 exhibited great adsorption ability and reusability in removing Fe3+, Cu2+ and Pb2+ from aqueous solution, and the saturated adsorption capacities reached up to 3.5, 0.9 and 1.1 mM/g. More importantly, other series MOFs constructed from organic linkers with amino groups decoration including MIL-101-NH2(Cr), MIL-53-NH2(Al), UiO-66-NH2(Zr) and MOF-5-NH2(Zn) also showed similar performance in the detection and removal of metal ions. Possible mechanisms for the fluorescence quenching and adsorption were investigated. All in all, the research results not only met the requirements of sensitively detecting and efficiently removing heavy metals, but also provided novel inspirations for future application of MOFs in the field related to environmental protection via specific surface functionalization.