Integrated Experimental and DFT Analysis of Copper Dissolution in ChCl-PTSA Deep Eutectic Solvent

This study examines copper dissolution from waste printed circuit boards (PCBs) in a ChCl-PTSA deep eutectic solvent (DES) using combined leaching experiments and DFT-based electronic-structure calculations. Experimentally, copper recovery at ۱۰۰ °C increased from ۷۹.۴% (۳۰ min) to ۹۶.۱% (۱۲۰ min) and reached ۹۷.۰% (۳۰۰ min), whereas recovery at ۶۰ °C progressed more slowly, from ۱۵.۸% to ۵۰.۱% and ۸۱.۶% over the same times. Dissolved-copper concentrations showed similar behavior, rising to ۱,۷۱۱ mg.L¹ at ۱۰۰ °C versus ۱,۴۴۰ mg.L¹ at ۶۰ °C after ۳۰۰ min. DFT results reveal that the Cu(I) complex exhibits a larger HOMO-LUMO gap (~۱.۱۴ eV) and thus higher electronic stability, while Cu(II) displays a smaller gap (~۰.۶۱ eV) with frontier orbitals localized on the PTSA sulfonate region, indicating greater reactivity.

کلیدواژه ها:

Copper leaching ، Deep eutectic solvent (DES) ، Solvometallurgy ، Waste printed circuit boards (PCBs) ، Density functional theory (DFT)