Highly Efficient and Selective Gold Recovery Based on Hypercross-Linking and Polyamine-Functionalized Porous Organic Polymers

Abstract

With the continuous increase of electronic products, there is an urgent need to effectively recover gold from e-waste and other secondary resources other than the original mine. Here, hypercross-linking and polyamine-functionalized porous organic polymers (Pc–POSS–POP) were designed and facially synthesized based on multiple azo-coupling polymerizations between 2,9,16,23-tetraaminophthalocyanine (H2Pc­(NH2)4) and octa­(aminophenyl)-t8-silsesquioxane (OAPS) for the first time. The reaction requires no metal as a catalyst, thereby benefiting the purification of the product and the industrial scalability. Pc–POSS–POPs possess a hypercross-linking structure, highly conjugated frameworks, nitrogen-rich active sites, and extensively visible and near-infrared light absorption, which was utilized as an absorbent to retrieve Au (III). The results demonstrated that Pc–POSS–POPs have a high adsorption capacity (862.07 mg g–1) and a rapid adsorption rate toward gold recycling. The maximum adsorption capacity could reach up to 1026.87 mg g–1 as in the case of light irradiation. Due to the strong N coordination sites and the electronic interaction between the −NH4 + groups of Pc–POSS–POPs and AuCl4 –, Pc–POSS–POPs also exhibited excellent selectivity toward gold over several coordinated metals [Cr (VI), Co (II), Cd (II), Ni (II), and Hg (II)]. These properties together with the good regenerative ability and superior recyclability demonstrated that Pc–POSS–POPs possess promising potential as hypercross-linking polymers for capturing and recycling of Au (III).

Au Nanoparticles in Silsesquioxane-Based Hybrid Networks by Simultaneous Recovery and Reduction of Au(III) in Wastewater

“…From the EDS images, the elements of C, O, N, and Au are dispersed uniformly in PCS-PAA. According to previous reports, the reduction reaction occurs during the adsorption of Au­(III) by the adsorbent. , …”

“…According to previous reports, the reduction reaction occurs during the adsorption of Au(III) by the adsorbent. 53,54 3.8. Catalytic Application of PCS-PAA-Au.…”

“…Further, the hybrid materials derived from SQs act not only as adsorbents but also as catalysts simultaneously. For example, our group synthesized two SQ-based semiconducting porous polymers, which exhibited high adsorption capacity and photocatalytic degradation of dyes or antibiotics. , By far, novel construction units and simple, mild preparation routes are still being explored to expand SQ-based materials. , …”

“…51,52 By far, novel construction units and simple, mild preparation routes are still being explored to expand SQ-based materials. 53,54 Mild conditions, a fast reaction rate, and no additional catalyst make the amine−ene reaction of polyamine with the acrylate group to be a facile route to prepare functional Scheme 1. Synthetic Route of Amine-Functionalized SQ-Based Network via the Amine−Ene Reaction materials.…”

Turning waste into wealth: efficient and rapid capture of gold from electronic waste with a thiourea functionalised magnetic core stirring rod adsorbent and its application for heterogeneous catalysis

“…5 However, electronic waste (e-waste) is considered one of the most attractive sources of gold due to its high content of precious metals. 6,7 Research has showed that one ton of abandoned mobile phones contains about 347 g of gold, and the gold content of 40 mobile phones is equivalent to mining 1 ton of ore, so it can be seen that e-waste is a "gold mine" that is still to be mined. [8][9][10] According to data from the International Telecommunication Union, a record 53.6 million tons of e-waste was generated worldwide in 2019, and this will rise to 74.7 million tons by 2030.…”