## 3 Results and Discussion  
### Structure and Morphology  
The morphology and structure are explored by SEM and TEM for MRGO, MRGO@ZIF-7, and MRGO@ZIF7-MIP, as shown in Figure 1. Figure 1a shows the SEM and TEM (inset) images of sample MRGO. Fe\({}_{3}\)O\({}_{4}\) microspheres are uniformly distributed on the RGO surface with an average particle size of about 200 nm. Figure 1b shows the SEM and TEM (inset) images of sample MRGO@ZIF-7, where Fe\({}_{3}\)O\({}_{4}\) and ZIF-7 have adhered well to the surface of wrinkled RGO. ZIF-7 demonstrates a three-dimensional block structure, smooth surface, and an average particle size of around 400 nm. Figure 1c shows SEM and TEM (inset) images of sample MRGO@ZIF7-MIP; the description shows that ZIF-7 and MRGO are covered by molecularly imprinted polymers when MIP is grafted onto the MRGO@ZIF-7 surface. The structural properties of the prepared experimental materials were characterized using the XRD technique (Figure 2). For MRGO, the peaks represent the Bragg reflections of (220), (311) and (400) facets, which match well with those of Fe\({}_{3}\)O\({}_{4}\) nanoparticles (JCPDS Card No. 19-0629), indicating the coating of Fe\({}_{3}\)O\({}_{4}\) microspheres on RGO [61]. After the decoration of ZIF-7, typical diffraction peaks of ZIF-7 emerge, consistent with the reference XRD pattern for the cubic ZIF-7 (CCDC Card No. 04-2541) [54]. Furthermore, the crystal plane diffraction peaks of Fe\({}_{3}\)O\({}_{4}\) microspheres can also be observed. These observations suggest that the introduction of ZIF-7 did not affect the crystalline structure of MRGO. When MIP was grafted onto the surface of MRGO@ZIF-7, the positions and widths of the diffraction peaks did not change, indicating that the crystalline structures of the Fe\({}_{3}\)O\({}_{4}\) microspheres and ZIF-7 were not affected by the grafted MIP. Analytical characterization was carried out regarding the specific surface area, total pore volume, and pore size distribution of experimental materials using the BET adsorption equation and BJH academic model. The nitrogen adsorption-desorption isotherms and pore size distributions of MRGO@ZIF7-MIP, MRGO@ZIF-7, and MRGO were analyzed, as shown in Figure 3. Figure 3a shows that the Brunauer-Emmett-Teller (BET) surface areas of MRGO@ZIF-7, MRGO@ZIF-7 MIP, and MRGO are 261.31 m\({}^{2}\) g\({}^{-1}\), 96.83 m\({}^{2}\) g\({}^{-1}\), and 51.98 m\({}^{2}\) g\({}^{-1}\), respectively. The introduction of ZIF-7 in the MRGO@ZIF-7 structure resulted in a significant increase in the specific surface area compared to MRGO [55], and the decrease in the specific surface area when its surface was grafted with MIP again proved the presence of MIP. In addition, all three materials exhibit type-IV adsorption isotherms, and their mesoporous structures are an important basis for their efficient ad sorption performance. Figure 3b,c shows the pore size distribution of MRGO@ZIF-7 and MRGO@ZIF-MIP. Both materials have a uniformly distributed pore structure with an average pore size of 1.848 nm and 3.823 nm, respectively. Raman spectroscopy is an effective method for characterizing the structure and properties of graphene materials, such as surface defects, edge structures, and doping states. Figure 4a shows the Raman spectra of MRGO, MRGO@ZIF-7, and RGO@ZIF-MIP. Two distinct absorption peaks appear in the spectra of all three materials for the G and D peaks, respectively. The G peak is the main characteristic peak of graphene materials, which is caused by the in-plane vibration of sp\({}^{2}\) carbon atoms and appears near 1580 cm\({}^{-1}\)[64]. The D peak is usually considered the disordered vibrational peak of graphene materials, which is caused by the lattice vibrations leaving the center of the Brillouin zone. It is used to characterize the structural defects on the surface of graphene materials and appears near  
Figure 3: (**a**) The nitrogen adsorption–desorption isotherms of MRGO@ZIF-MIP, MRGO@ZIF-7 and MRGO and (**b,c**) pore size distribution of MRGO@ZIF-7 and MRGO@ZIF-MIP.