Microstructure engineering of two-dimensional PAF for targeted Pd(II) up-cycling from wastewater

The continuous innovation in integrated management strategies based on precise control of interactions is crucial for promoting sustainable recycling of precious metals from waste. Porous aromatic frameworks (PAFs) are promising regarding the capture of precious metals, but still lacks decisive molecular engineering or design rules. This study focusses on advanced concepts of direct modulating of active centers, serial PAFs with differentiated micro-dimensional central are well-designed for targeted up-cycling of Pd(II) from wastewater. Impressively, two-dimensional PAF (PAF-2D) possess optimal π-conjugated structure with highest C p z band center allow maximum electron injection from Pd(II), generating a satisfactory Pd(II) selectivity coefficients improved by an order of magnitude than that of PAF-3D and PAF-1D. In addition, PAF-2D possess ultra-high treatment of 1.81 × 10 4 bed volumes for actual Pd-wastewater. This study provides molecular understandings of micro-dimensionally determined the preferred p -orbital-dominated reactivity, guiding the next-generation innovation of valuable recovery blueprint. A fresh concept of direct modulating of active centers were proposed, and PAF-2D possess optimal π-conjugated structure to selectively up-cycle Pd(II) into value-added Pd(0) from actual wastewater. It provides the molecular insights into structure-property-performance relationship for futuristic sustainable reclamation. • Rationally micro-dimensional design of PAFs promoted the custom-tailored reactivity. • Selective up-cycling of Pd(II) into Pd(0) was achieved in actual wastewater. • The molecular insights into structure-property-performance relationship