Researchers believe they have found a sustainable solution to the toxic lead (Pb) ions inside perovskite – calcium titanium oxide – solar panels. Until now, the residual ions have been a barrier to full-scale commercial recycling.
Managing lead ions in waste PV modules using common organic solvents is challenging because of the lack of suitable adsorbents on whose surface the ions can adhere.
‘We have found a new adsorbent for both the separation and recovery of Pb from perovskite solar cell pollutants,’ reveals Dr. Soyeon-Park of Sungkyunkwan University. Park explains that the new absorbent, synthesized iron-incorporated hydroxyapatite, has a strongly negatively charged surface that improves electrostatic interaction through surface-charge delocalization.
‘We demonstrate the feasibility of a complete Pb management process, including the purification of Pb-containing non-aqueous solvents below 15 parts per 109,’ she reports.
‘This level is compliant with the standards of the US Environmental Protection Agency, as well as recycling 99.97% of Pb ions by forming lead iodide.’
The researchers are confident that their study will enable a zero lead emission process for the manufacture of lead-based perovskite. They have shared the details of their work in a paper in the journal ‘Nature Sustainability’.
The worldwide solar panel market increased 12% to total almost 630 GW last year, according to the latest market data.