Iridium complex modified MOFs for enhancing photocatalytic hydrogen evolution

Abstract

In this paper, we prepared an iridium(III) complex modified MOF (cmrIr/Pt@UiO-66-NH₂) to combine the excellent light absorption properties of iridium(III) complexes and good photostability of metal–organic frameworks (MOFs). Photocatalytic tests show that even with extremely low content of cmrIr, cmrIr/Pt@UiO-66-NH₂ achieves enhanced hydrogen evolution performance while maintaining the inherent photostability of the MOF. The hydrogen evolution amount of cmrIr/Pt@UiO-66-NH₂ (with only 0.2% of Ir content) is 446.4 μmol g⁻¹, which is about 2.5 times that of Pt@UiO-66-NH₂ (180.7 μmol g⁻¹). Solid UV, photocurrent response and electrochemical impedance tests indicate that the introduction of the iridium(III) complex promotes the separation of electrons and holes, thus sensitizing the MOF and resulting in enhanced photocatalytic activity. This study provides a new insight for the design of hybrid material photocatalysts.