Ternary NiFeMnOx compounds for adsorption of antimony and subsequent application in energy storage to avoid secondary pollution

Abstract

Abstract Antimony (Sb) has been widespreadly applied in industry, but it is one of the major pollutants due to the intrinsic biological toxicity. Using chemical adsorption method to recover Sb in sewage is of great value for both academic and industry research. Considering the treatment of the used-adsorbent to avoid secondary pollution, the design of adsorbent should take advantages of both good adsorption capacity and the sequential sustainability of the used adsorbent. Herein, the ternary Ni-Fe-Mn oxide compounds (NiFeMnOx) was prepared as the good adsorbent to recycle Sb. The recovered antimony-enriched waste adsorbent (NiFeMn/SbOx) was used as a supercapacitor and showed excellent energy storage performance. The NiFeMnOx has the maximum adsorption capacity of 553\xa0mg/g for antimony. The mechanism of high adsorption capacity can be ascribed to the interaction caused by hydrogen bonding, the intercalation and inner-sphere complexation. What’s more, a part of Sb(III) was detoxified to less harmful Sb(V) during the adsorption process, this also suggests the redox procedure in the adsorption. In the sequential application, the NiFeMn/SbOx based hybrid supercapacitor exhibits good performance with 108.3 mAh/g at the current density of 1 A/g even loading the highly massive active material (10\xa0±\xa00.5\xa0mg/cm2). This work provides a new pathway not only to exert value-addition of antimony, but also to avoid secondary pollution caused by waste adsorbents.