Photochemically Enhanced Selective Adsorption of Gold Ions on Tannin-Coated Porous Polymer Microspheres
| Autor: | Sun Young Choi, Jeonga Kim, Kyeong Rak Kim, Jin Woong Kim, Yeongran Hong, Cafer T. Yavuz, Yoon Sung Nam |
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| Rok vydání: | 2019 |
| Předmět: |
Aqueous solution
Materials science Ethylene glycol dimethacrylate Metal ions in aqueous solution 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Metal chemistry.chemical_compound Adsorption chemistry Chemical engineering Selective adsorption visual_art visual_art.visual_art_medium General Materials Science Chelation 0210 nano-technology Mesoporous material |
| Zdroj: | ACS Applied Materials & Interfaces. 11:21915-21925 |
| ISSN: | 1944-8252 1944-8244 |
| DOI: | 10.1021/acsami.9b05197 |
| Popis: | Metal recovery from electronic waste and industrial wastewater has attracted increasing attention to recycle precious metals and inhibit the emission of hazardous heavy metals. However, the selective recovery of precious metals with a large quantity is still very challenging because wastewater contains a variety of different cations while precious metal ions are relatively scarce. Here, we introduce a simple method to selectively increase the adsorption of gold ions using tannin-coated porous polymer microspheres through photochemical reduction. Mesoporous poly(ethylene glycol dimethacrylate- co-acrylonitrile) microspheres with an average pore diameter of 13.8 nm were synthesized and used as an adsorbent matrix. Tannic acid (TA) was deposited onto the internal pores of the polymer matrix by simple immersion in an aqueous milieu. TA coatings increased the maximum number of adsorbed gold ions by 1.3 times because of the well-known metal ion chelation of TA. Under light illumination, the maximum number of adsorbed gold ions dramatically increased by 6.1 times. We examined two distinct mechanisms presumably involved in the enhanced adsorption: the photooxidation of TA and plasmon-induced hot electrons. Moreover, TA-coated microspheres exhibited remarkable selectivity for gold ions among competing metal ions commonly found in waste resources. This work suggests that the photochemically activated TA can serve as an excellent adsorbent for the selective and efficient recovery of gold ions from wastewater. |
| Databáze: | OpenAIRE |
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