Highly-efficient synthesis of heavy metal adsorbents by using spent lithium-ion battery anode graphite via one-step mechanochemistry process

Resource recycling has taken center stage of global carbon neutrality. In this study, we reclaimed spent graphite (SG) from retired lithium-ion batteries (LIBs) and introduced potassium permanganate powder to prepare amorphous MnO 2 loaded graphite oxide (AMO@GO) via one-step mechanochemical method for heavy metals adsorption. The synthesized AMO@GO was characterized by X-ray diffraction (XRD), Raman spectra, X-ray Photoelectron Spectroscopy (XPS), Brunauer-Emmett-Teller Method (BET), Fourier Transform Infrared Spectrometer (FTIR), and Scanning Electron Microscope (SEM), which illustrated AMO@GO had richer pore structure, ample active groups, strong surface ion exchange activity. These properties made AMO@GO a highly potential adsorbent for aqueous heavy metal contamination. The results showed the adsorption capacities of AMO@GO for Cu 2+ , Pb 2+ and Cd 2+ in the water body can reach 233.99 mg/g, 353.13 mg/g and 257.95 mg/g respectively (calculated by Langmuir isotherm model), significantly higher than similar graphite-based adsorbents. Through in-depth studies of the adsorption mechanism, we found that the ion exchange of heavy metals with active groups on the surface of graphite oxide and amorphous MnO 2 was the main source of sample adsorption capacity.