Effect of Lanthanum Doping on the Microstructure, Thermal Stability, and CO2 Adsorption Property of ZIF-8

The reaction materials La(NO3)3·6H2O, Zn(NO3)2·6H2O, and 2-methylimidazole were mixed in a certain proportion. A research process innovatively adopts the parallel flow-drop solvothermal method and a lanthanum-doping method to achieve the synthesis of metal organic frameworks. In this study, we successfully introduce lanthanum into the framework of ZIF-8 to stabilize the spatial structure and improve its performance. The structure and properties of La-ZIF-8 were characterized by the X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetry analysis (TGA), and fourier transform infrared spectroscopy (FTIR). The relationship between microstructure stability and macroscopical properties is illustrated. The results show that the doping of lanthanum is beneficial for improving the thermal stability and CO2 adsorption property of ZIF-8 because of the improvement in the microstructure. The introduction of lanthanum to the ZIF-8 is also beneficial for forming porous frameworks and raising the thermal stability and CO2 adsorption properties. The crystallinity, structure, morphology, and thermal stability of La-ZIF-8 are optimal at the La content of 2 atom.%.