Study on the dissolution of precious metals in the nitrogrn-oxygen free radical ionic liquid system

In order to develop an efficient and environmentally friendly method for the recovery of precious metals, a functionalized ionic liquid containing free radicals (1-methyl-3-(2-oxo-2-(2,2,6,6-tetramethyl-1-oxo-4-piperidinoxy) butyl) imidazole trichloro-1-bromoaluminium salt) was designed and synthesized. This was achieved by combining 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), which possesses oxidizing properties, with halide ions that exhibit complexing abilities. Notably, under optimal conditions, a maximum gold dissolution rate of 100 % was attained. X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and Raman spectroscopy analyses were conducted to elucidate the dissolution mechanism. Ultimately, these functionalized ionic liquids can be utilized for the dissolution of precious metals in CPU pins and waste catalysts. This study presents an effective approach for the recovery of precious metals.