Syntheses, structures and Br2 uptake of Cu(I)-bipyrazole frameworks

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

Bromine (Br2) plays vital roles in various chemical reactions in laboratories and industries, however, the excessive use of Br2 inevitably causes their leakage, which increases the risk of environmental pollution. Although efficient Br2 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 Br2, while abundant polar groups enhances the physical adsorption of Br2, thus realizing an extremely high Br2 removal capacity of 9511 mg g-1, which far exceeds the average level of Br2 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.

Tandem Efficient Bromine Removal and Silver Recovery by Resorcinol-Formaldehyde Resin Nanoparticles

Halogen wastewater greatly threatens the health of human beings and aquatic organisms due to its severe toxicity, corrosiveness, and volatility. Efficient bromine removal is therefore urgently required, while existing Br₂-capture materials often face challenges from limited water stability and possible halogen leaking. We report a facile and efficient aqueous Br₂ removal method using submicron resorcinol-formaldehyde (RF) resin nanoparticles (NPs). The abundant aromatic groups dominate the Br₂ removal by substitution reactions. An excellent Br₂ conversion capacity of 7441 mg g_RF^-1 was achieved by RF NPs that outperform state-of-the-art materials by ∼2-fold, along with advantages including good water stability, low cost, and easy fabrication. Two recycling-coupled (electrochemical or H₂O₂-involved) Br₂ removal routes further reveal the feasibility of in-depth halogen removal by RF NPs. The brominated resin can be downstream upcycled for silver recovery, realizing the harvesting of precious metal, reducing of heavy-metal pollution, and resource utilization of brominated resin.

Calix[4]pyrrole-Based Azo-Bridged Porous Organic Polymer for Bromine Capture

The toxicity, corrosiveness, and volatility of elemental bromine presents challenges for its safe storage and transportation. Purification from other halogens is also difficult. Here, we report an easy-to-prepare calix[4]pyrrole-based azo-bridged porous organic polymer (C4P-POP) that supports efficient bromine capture. C4P-POP was found to capture bromine as a vapor and from a cyclohexane source phase with maximum uptake capacities of 3.6 and 3.4 g·g^-1, respectively. Flow-through adsorption experiments revealed that C4P-POP removes 80% of the bromine from a 4.0 mM cyclohexane solution at a flow rate of 45 mL·h^-1. C4P-POP also allowed the selective capture of bromine from a 1:1 mixture of bromine and iodine in cyclohexane.