One-Step Simultaneous Electrosynthesis of Copper and Selenium from CuSe in Choline Chloride-Urea Deep Eutectic Solvent.

Conventional selenium recovery poses environmental and sustainability challenges. To address this, we propose a one-step method for the separation and recovery of copper and selenium from dissolved CuSe in a choline chloride-urea deep eutectic solvent (DES). In this process, copper, having an average particle size of 0.277 μm, is electrodeposited on the cathode and selenium nanorod powder, having an average particle aspect ratio of 14.52, forms around the anode. Of note, CuSe is effectively converted to Cu and Se in the DES at 80 °C, achieving yields of 69.81 and 73.38%, respectively, after 48 h of scaled-up electrolysis. Importantly, the recyclability of the DES was confirmed, yielding the stable recovery of metallic copper and monolithic selenium through secondary dissolution and the subsequent re-electrolysis of CuSe. This approach presents an innovative, green, and sustainable strategy for recovering valuable elements from other types of copper anode slimes.