Cu-MOF/Iodine Synergistic Electrochromic System for Energy-Efficient Smart Windows

Herein, through an interface–electrolyte synergistic strategy, we construct a Cu-MOF (HKUST-1) host interface and a water-in-salt electrolyte system to regulate iodine redox electrochemistry.

The unsaturated copper coordination sites of HKUST-1 chemically anchor polyiodides to suppress the shuttle behavior, and the reversible redox activity of Cu²⁺ sites provides additional electron transfer pathways for iodine conversion. Impressively, this system achieves voltage-selective spectral modulation covering visible and near-infrared regions via a preoxidation pathway. The modified electrode delivers an optical contrast of 87.37% at 1100 nm and 91.41% at 550 nm, retaining 89.06% of its optical contrast after 6000 cycles, showing promise for smart window applications.