Ti3C2Tx MXenes: From Recovery of Pb from Perovskite Solar Cells to Supercapacitor Usage

Journal article, 2025

Sustainable disposal and valorization of recovered lead from end-of-life perovskite solar cells (PSCs) remain critical challenges from environmental and electrochemical perspectives. Here, we demonstrate a dual-function process wherein Ti3C2Tx MXenes adsorbents are first employed to recover lead from green acetone-based PSC recycling waste and subsequently repurposed as high-performant supercapacitor electrode active materials. Remarkably, Ti3C2Tx achieves >99.9% Pb2+ ion removal from 100 ppm Pb/acetone solutions, with an adsorption capacity reaching up to 555 mgg(-1). After adsorption, the Pb-loaded MXene (Ti3C2Tx/Pb-ads) retains its structural integrity and exhibits significantly enhanced electrochemical performance. Electrochemical cycling in a sodium acetate aqueous electrolyte reveals a doubled specific capacity of the MXenes, from ca. 30 Cg(-1) to ca. 60Cg(-1), by introducing reversible Pb2+/Pb-0 redox activity while maintaining the initial MXene pseudocapacitive behavior. Overall, this conceptual study demonstrates a closed circular materials loop by recovering a green solvent from the PSC recycling, while transforming a hazardous waste stream into a value-added energy storage material.