An Iodide-Mediated Microdroplet for Efficient Ozone Decomposition

Microdroplet chemistry offers a promising platform for advancing green chemical processes; however, its limited reaction efficiency has restricted practical applications. Herein, we report a scalable iodide-mediated microdroplet system that markedly enhances stability and rate. The iodide-mediated microdroplet system (0.1 wt %) can achieve 100% ozone (O₃) decomposition at the gas-liquid interface for 120 h and exhibits continuous and stable characteristics. Experiments proved that compared with bulk solution, I^- enrichment and strong O₃ affinity at microdroplet interfaces promote the accumulation of reactants and stabilize transition states. Moreover, the strong interfacial electric field induces hydroxide dissociation and drives electron-mediated regeneration of I^- from iodine species, thereby sustaining continuous O₃ reduction. Compared with the spray reactor, the iodide-mediated microdroplet reactor achieves a 100% O₃ conversion, above 5-fold longer operational stability, 8.0% cost, and 10.4% energy consumption. Life cycle assessment further confirms its superior environmental and economic performance. This work provides a mechanistic understanding of the iodide-driven interfacial redox reaction and offers a scalable, green approach for O₃ purification.