Compositional and Structural Evolutions of Zn-Based Metal–Organic Frameworks During Pyrolysis

Metal–organic framework (MOF)-derived nanostructures for electrochemical applications have attracted tremendous attention; therefore, understanding of the decomposition mechanism of MOFs during thermal treatment is crucial for the design and synthesis of MOF-derived nanomaterials. Here, a systematic investigation was carried out to study the pyrolysis process of a Zn-based metal–organic framework (Zn-MOF), which revealed the compositional and structural evolution by in situ diffuse reflectance infrared Fourier transform spectroscopy, thermogravimetric analysis–differential scanning calorimetry, and X-ray diffraction methods. The continuous change of the nature of surface of pyrolytic Zn-MOF at different temperatures was also studied by the cyclic voltammetry method, described by the fractal concept of electrochemical surface. The results show that the pyrolysis of Zn-MOF occurs at ca. 450 °C and the decomposition products are amorphous carbon and ZnO. The pyrolysis temperature plays a decisive role in the formation of the porous structures of carbon matrices and the evolution of the surface geometry of the products. The presented approach would be instructive and informative for the preparation of MOF-derived nanostructures.