Closed-loop recycling of lead iodide precursor from waste organic solvents in the production of perovskite solar cells: Toward sustainable photovoltaics.

Perovskite solar cells (PSCs), characterized by high efficiency, have demonstrated significant potential in solar energy harvesting. However, the PSCs production process usually generates substantial waste containing polar organic solvents, i.e., N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO), which are contaminated with high-concentration Pb(Ⅱ). This study introduces a closed-loop recycling approach to separate and recover Pb(Ⅱ) from waste organic solvents using a cation-exchange resin, enabling lead reuse in PSCs manufacturing. The resin efficiently adsorbs and desorbs Pb(Ⅱ) from the solvents, achieving a recovery efficiency of over 97 % and demonstrating excellent reusability. The separated lead solution is further converted into high-purity lead iodide (PbI2) precursor (99.99 %). PSCs fabricated with the recovered PbI2 precursor exhibit a power conversion efficiency (17.72 %) and current density (17.59 mA/cm2), comparable to devices made with commercial PbI2 precursor (18.39 %, 17.27 mA/cm2). This work presents an environmentally-friendly method for efficient lead separation and recovery from PSCs production waste solvents, promoting the sustainable development of the PSC industry.