深共熔溶液(Deep Eutectic Solvent, DES)為近年廣泛研究的綠色溶液之一，將氯化膽鹼和尿素以莫耳比1:2的比例混合是典型的DES。雖然DES對多種金屬氧化物都有良好溶解度，但其溶解機制仍甚不清楚。本研究因此探討氯化膽鹼和尿素的組成成分，在溶解氧化亞銅(Cu2O)所扮演的角色。透過比較氧化亞銅溶解在DES、接近飽和的氯化膽鹼水溶液、尿素水溶液的溶解度和紫外光-可見光譜，發現尿素對溶解Cu2O的影響大。此外，比較銅氯化物、Cu2O和銅金屬溶解在DES和水溶液中的結果，可推論Cu2O溶於DES的機制，是由1價的銅離子與尿素形成錯合物而穩定溶解。最後，探討改變尿素在DES比例，發現增加尿素比例可提高DES對Cu2O的溶解能力，但須將溶液溫度保持在70 ℃才能有較好的操作條件。;Recently, Deep Eutectic Solvent (DES) is known as one of the widely studied green solution with a typical molar mixing ratio of 1:2 between choline chloride and urea. Although many metal oxides have good solubility in DES, the mechanism of it is still lacking. This study consequently investigated the role of choline chloride and urea in dissolving copper (I) oxide (Cu2O). Urea was found to play a significant role in dissolving Cu2O from comparing the solubility and UV-vis absorption spectrogram of dissolved Cu2O in DES, near saturated choline chloride, and urea aqueous solutions. Moreover, the mechanism of dissolving Cu2O in DES was derived from the formation of a stable complex between copper (I) and urea by comparing copper (II) chloride, Cu2O, and metal copper dissolved in both DES and deionized water. Finally, the solubility of Cu2O in DES can be improved by varying urea fractions in DES and maintained temperature at 70 ℃ during operation.
