Abstract In this paper, trioctylphosphine oxide (TOPO) was combined with some environmental-friendly molecules to form hydrophobic deep eutectic solvents (HDESs) for platinum (Pt) extraction from secondary resources. Due to the formation of HDESs, the loss of TOPO content in the aqueous solution obviously decreased. Then, the extraction behaviors under different vibrating time, acidity and salinity (NaCl/NaBr) were investigated and discussed. Among all the constructed HDESs, the TOPO/1-butanol showed the best Pt(IV) extraction performance (98.9%) in 5.6 mmol·L−1 Pt(IV) solution. Ion-association mechanism in the extraction process was proposed through the analysis of UV–vis and FT-IR spectra. In addition, the HDESs exhibited excellent selectivity to Pt(IV) in the experiments of multi-metal selective extraction. The extracted Pt(IV) could be easily and completely stripped by adding 3 mL 0.5 mol·L−1 NaOH solution, and the extraction ability of recovered extractants remained constant after 4 cycles of extraction tests. Furthermore, by using RSM-CCD optimization, the operating concentration of acidity and salinity was obtained: 1.27 mol·L−1 HCl and 2.65 mol·L−1 NaCl. Under optimal experimental conditions, the designed processes of Pt(IV) extraction further improved recycling efficiency.

中文翻译：

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基于三辛基氧化膦的疏水性低共熔溶剂萃取铂 (IV)

摘要 在本文中，三辛基氧化膦 (TOPO) 与一些环保分子结合形成疏水性低共熔溶剂 (HDESs)，用于从二次资源中提取铂 (Pt)。由于HDESs的形成，水溶液中TOPO含量的损失明显减少。然后，研究和讨论了不同振动时间、酸度和盐度（NaCl/NaBr）下的提取行为。在所有构建的 HDES 中，TOPO/1-丁醇在 5.6 mmol·L-1 Pt(IV) 溶液中表现出最佳的 Pt(IV) 提取性能（98.9%）。通过对紫外-可见光和红外光谱的分析，提出了提取过程中的离子缔合机制。此外，在多金属选择性萃取实验中，HDESs 对 Pt(IV) 表现出优异的选择性。加入3 mL 0.5 mol·L-1 NaOH溶液后，提取的Pt(IV)可以很容易地完全脱除，并且经过4个循环的提取试验后，回收的提取剂的提取能力保持不变。此外，通过使用RSM-CCD优化，得到酸度和盐度的操作浓度：1.27 mol·L-1 HCl和2.65 mol·L-1 NaCl。在最佳实验条件下，设计的 Pt(IV) 提取工艺进一步提高了回收效率。