Single Pt Atoms Confined into a Metal–Organic Framework for Efficient Photocatalysis

Abstract

It is highly desirable yet remains challenging to improve the dispersion and usage of noble metal cocatalysts, beneficial to charge transfer in photocatalysis. Herein, for the first time, single Pt atoms are successfully confined into a metal–organic framework (MOF), in which electrons transfer from the MOF photosensitizer to the Pt acceptor for hydrogen production by water splitting under visible-light irradiation. Remarkably, the single Pt atoms exhibit a superb activity, giving a turnover frequency of 35 h⁻¹, ≈30 times that of Pt nanoparticles stabilized by the same MOF. Ultrafast transient absorption spectroscopy further unveils that the single Pt atoms confined into the MOF provide highly efficient electron transfer channels and density functional theory calculations indicate that the introduction of single Pt atoms into the MOF improves the hydrogen binding energy, thus greatly boosting the photocatalytic H₂ production activity.

Metal–organic frameworks (MOFs) are promising templates to stabilize single atoms for catalysis. Herein, a porphyrinic MOF is used as template to obtain single platinum atoms for the first time. The obtained catalyst exhibits superb visible-light photocatalytic efficiency in hydrogen production and the turnover frequency value of single platinum (Pt) atoms is ≈30 times than that of MOF-stabilized platinum nanoparticles.

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