Carbazole–Phosphazene Based Polymer for Efficient\nExtraction of Gold and Precious Elements from Electronic Waste

The continuous advancement\nof industry and technology has significantly\nincreased electronic waste, which contributes to the depletion of\nvaluable metal reserves. Therefore, it is crucial to recycle precious\nmetals in electronic waste effectively and sustainably. This study\nintroduces a novel approach by applying a carbazole–phosphazene-based\npolymer, EBE-06, in a two-stage leaching method for efficient metal\nextraction. In the first leaching stage, tin is selectively separated\nusing an acid solution at a controlled pH. In the second stage, valuable\nmetals such as gold are recovered through adsorption onto EBE-06.\nThe polymer exhibited a 99% gold adsorption rate within 1 h, independent\nof pH, and a maximum adsorption capacity of 1.787 g of gold per gram\nof polymer. The desorption process yielded 95% efficiency, with the\npolymer maintaining 94% efficiency over three cycles of use.