Atomically dispersed Pt inside MOFs for highly efficient photocatalytic hydrogen evolution

Impregnating noble metals in metal-organic frameworks (MOFs) for obtaining effective catalysts for the photocatalytic process is of great significance but remains very challenging. Herein, for the first time, atomically dispersed Pt atoms were successfully impregated inside the MOF UiO-66 with the assistance of supercritical carbon dioxide (SC CO₂). Our study demonstrated that the SC CO₂-directed strategy makes Pt undergo a stable encapsulation inside UiO-66, realizing a stage for the rapid transfer of photogenerated electrons between the components of the composite, hence dramatically increasing the catalytic effect. Further, theoretical calculations demonstrated the experimental characterization of the unique structure. Moreover, the as-prepared hybrid structure of Pt@UiO-66 composites presented an extremely high photocatalytic efficiency for hydrogen evolution under visible-light irradiation. An unusual H₂ production rate of 3871.4 μmol h^-1 g^-1 could be achieved by Pt@UiO-66 under visible-light irradiation. This was nearly 50 times higher than the H₂-evolution rate achieved by pure UiO-66 under the full spectrum.