Ultra‐High Bromine Removal from Waste Water and Downstream High‐Value Utilization Using Melanin‐Like Polymers

Abstract Bromine (Br 2 ) plays vital roles in various chemical reactions in laboratories and industries, however, the excessive use of Br 2 inevitably causes their leakage, which increases the risk of environmental pollution. Although efficient Br 2 capture is highly desirable, current removal materials still face grand challenges from unsatisfactory removal efficiency as well as limited function. Polydopamine (PDA), as the most representative analog of melanin‐like polymers, has shown great potential in different fields during the past few decades. Herein, a triple‐level chemical engineering process is innovatively proposed to achieve the high‐value application of PDA. The active hydrogens of aromatic groups within PDA nanoparticles (NPs) enable the active substitution reactions with Br 2 , while abundant polar groups enhances the physical adsorption of Br 2 , thus realizing an extremely high Br 2 removal capacity of 9511 mg g −1 , which far exceeds the average level of Br 2 removal materials reported. More interestingly, the resulting brominated‐PDA (PDA‐Br) NPs can be downstream upcycled to realize harvesting of precious metal silver/gold, and the resulting Ag + ‐loaded PDA‐Br NPs (PDA@AgBr NPs) further exhibits superior anti‐bacterial ability. Overall, this work not only innovatively expands the emerging application scope of melanin‐like polymers, but also paves a new pathway toward the design of robust materials for high‐value utilization.