A robust aerogel incorporated with phthalocyanine-based porous organic polymers for highly efficient gold extraction

• Published in: Separation and purification technology 2025-02, Vol.354, p.129451, Article 129451
• Main Authors: Chen, Shenghuang, Ding, Rui, Li, Baoyu, Lu, Jitao, Zhang, Xiaomei
• Format: Article
• Language: English
• Subjects: Aerogel; Chitosan; Gold adsorption; Polyethyleneimine; Porous organic polymers
• ISSN: 1383-5866
• DOI: 10.1016/j.seppur.2024.129451

[Display omitted] The gold recovery from electronic waste liquid is of great significance to the recycling of precious metals and environmental restoration. Adsorption method is the preferred technique for gold recovery, but its expansion and application prospects were often limited by the workability and recyclability of common solid powder adsorbents. Herein, a solid absorbent powder (phthalocyanine-based POP, TD-POP) was integrated into chitosan/polyethyleneimine aerogel (TD-POP@CS/PEI-2) via a facile cross-linking and lyophilization strategy. As expected, TD-POP@CS/PEI-2 possessed outstanding mechanical toughness and stability, demonstrating efficient and specific adsorption for Au (III). The maximum adsorption capacity was 2169 mg g−1, higher than most of the absorbents. TD-POP@CS/PEI-2 aerogel also exhibited fast kinetics (recovery efficiency of 81.3 % within 3 h), good selectivity (recovery efficiency of 98.35 % at 10 times concentration of Al3+, Zn2+, Cu2+ Cd2+, Co2+, Ni2+, Mn2+, and Cr6+ than Au ions) and reusability (eight times). Multiple characterizations revealed the adsorption mechanism, which implied that the excellent adsorption properties of the aerogel were ascribed to the electrostatic attraction between cationic aerogel and AuCl4− anion, coordination interaction between nitrogen-containing active sites and Au (III), and reduction of Au (III) by TD-POP@CS/PEI-2 aerogel. This work provides a valuable and promising strategy to design scalable and sustainable adsorbents for capture precious metals, also promotes the development of integral adsorbent for environmental remediation.