Toxic metal pollution is one of the environmental problems that seriously affect water resources and ecosystems. Antimony, recognized for its teratogenic and carcinogenic properties, poses significant health risks due to its widespread presence in natural water sources. In this study, cobalt-doped manganese oxide bimetallic composites were designed as an efficient adsorbent for the antimony removal from water. The adsorbent exhibits robust performance over a range of pH values, achieves a significant adsorption capacity of 591.1 mg/g, and exhibits adsorption equilibrium within 25 min. The effectiveness of the adsorption is attributed to the interaction between metal-O bonds and antimony, as well as the hydrogen bonding. In line with the concept of sustainable development, waste adsorbents are used as negative electrodes for SbO2--based aqueous alkaline batteries. It exhibits a high reversible specific capacity of 122.8 mAh·g−1. This research not only sheds light on innovative approaches to antimony removal but also opens up avenues for the sustainable reuse of waste materials, in line with the principles of sustainable development.