Tailoring hydropathicity and charge characteristics in magnetizable polyhedral oligomeric silsesquioxane adsorbent for improved gold capture

Abstract

Amidst the rapid proliferation of electronic products, an urgent need arises for the efficient retrieval of gold from unconventional sources like electronic waste. This study introduces a straightforward approach for crafting a range of magnetic POSS adsorbents functionalized with monothioglycerol (Fe3O4@POSS-MTGx), demonstrating effective and selective Au(III) capture from aqueous solutions. The resulting Fe3O4@POSS-MTG3 showcases a mesoporous structure with a specific surface area of 113.24 m2 g−1 and a pore size distribution of 4.9 nm. Batch adsorption experiments underscore the high adsorption capacity of Fe3O4@POSS-MTG3, reaching 363.57 mg g−1, alongside a rapid gold recovery rate (achieving 90.6 % of equilibrium adsorption capacity within 4 h). The impact of Fe3O4@POSS-MTG3 on the adsorption capacity of Au(III) under varying light conditions was further examined, revealing an adsorption capacity of 471.3 mg g−1 under white light and 618.49 mg g−1 under ultraviolet light. Leveraging strong sulfur coordination sites, the material showcased selectivity for Au(III) over coexisting ions (Co(II), Cr(III), Cu(II), K(I), Mn(II), Na(I), Ni(II), Zn(II)). These attributes, alongside outstanding regenerability and recyclability, underscore the promising potential of Fe3O4@POSS-MTGx in capturing and recovering Au(III), thus presenting a bright prospect for gold extraction from e-waste.