An iridium-decorated metal-organic framework for electrocatalytic oxidation of nitrite

Spatially dispersed redox-active iridium sites are immobilized throughout the porous framework of a zirconium-based metal-organic framework (MOF), UiO-66, to enable charge hopping in the MOF. The resulting iridium sites within UiO-66 not only permit redox hopping-based electron transport within the MOF in aqueous electrolytes, but also exhibit electrocatalytic activity for the oxidation of nitrite. The pH of the electrolyte for this electrocatalysis is optimized, and the electrocatalytic mechanism occurring on the Ir-decorated UiO-66 thin films is investigated. The material is further applied for ampemmetric nitrite sensing in aqueous solutions. Owing to its high porosity, the Ir-decorated UiO-66 achieves a good sensitivity (168.8 mu A/mM-cm(2)) for detecting nitrite with a low limit of detection (0.41 mu M).

Automated summary

By immobilizing spatially dispersed redox-active iridium sites throughout the porous framework of UiO-66, charge hopping and electron transport within the MOF are enabled, along with electrocatalytic activity for the oxidation of nitrite. The optimized pH of the electrolyte is studied for this electrocatalysis, and the mechanism occurring on Ir-decorated UiO-66 thin films is investigated for nitrite sensing. The Ir-decorated UiO-66 achieves a good sensitivity (168.8 mu A/mM-cm(2)) for detecting nitrite with a low limit of detection (0.41 mu M) due to its high porosity.