From electronic wastes to efficient and specific filtration membranes: A photovoltaic upcycling case enabling silver urban mining

The increasing demand for sustainable and environmentally friendly solutions has driven research into the reuse of photovoltaic (PV) waste. In this study, a bimetallic metal-organic framework (Cu/Ag MOF) was synthesized directly from PV waste leachate and subsequently integrated into a thin-film nanocomposite (TFN) membrane for nanofiltration-based silver (Ag) recovery. The optimized TFN membrane demonstrated high selectivity of (<Si>_{Ag⁺,Cu²⁺}=7.99) and recovery of 99.1 % for Ag over five repeated filtration cycles while maintaining the membrane integrity. The membrane also exhibited exceptional antifouling performance, with a flux recovery rate (FRR) of 92.8 %, and high stability with only 0.5 % detachment of Cu/Ag MOF after prolonged use. Additionally, the high water permeability (58.6 L/(m²·h·bar)) of the TFN membrane has enabled efficient filtration performance. These results highlight the feasibility of Cu/Ag MOF-based TFN membranes for sustainable Ag recovery from PV waste and likely other electronic waste leachates, contributing to circular economy initiatives and resource recovery technologies.