Sustainable antimony management via porphyrin ligand-based MOFs: From enrichment of antimony from water to the utilization in SbO2– based aqueous batteries

Abstract

Antimony-based materials are rapidly developing towards industrialization, making it crucial to control potential toxicity and address sustainable antimony management. A strategy has been proposed to remove antimony from wastewater and sustainably convert the resulting antimony-enriched waste adsorbent into electrode materials. Herein, the porphyrin ligand-based zirconium metal-organic framework (PCN-222) was constructed for antimony adsorption. The antimony is initially adsorbed onto the Zr cluster nodes, spreads along the skeleton through hydrogen bonds, and finally terminates at the N-coordination fixed sites in the porphyrin ligand. Afterwards adsorption, the antimony-enriched waste adsorbent is converted to Sb nanoparticles embedded in N-doped porous carbon composite by one-step carbothermal reduction. The composite is applied into SbO2--based aqueous alkaline battery, which displays a high specific capacity with 122.5 mAh/g at 1 A/g and good cycling stability. The work provides valuable insights into the treatment of contaminated water and the management of antimony resources.