Stable and Efficient Homogeneous Photocatalytic H2 Evolution Based on Water Soluble Pyrenetetrasulfonic Acid Functionalized Platinum Nanocomposites

Herein, 1,3,6,8‐pyrenetetrasulfonic acid (PTSA) functionalized Pt nanocomposites were synthesized and characterized by UV/vis, X‐ray photoelectron spectroscopic (XPS), FTIR, TEM, and XRD methods. Pyrenetetrasulfonic acid was not only used as the stabilizer to prevent agglomeration of Pt nanoparticles but also served as the light‐harvesting photosensitizer, absorbing irradiating light and transferring photoexited electrons to the platinum nanoparticles. The occurrence of the photoinduced electron transfer process was confirmed by the combination of time‐resolved fluorescence and photoelectrochemical spectral measurements. Photocatalytic results showed that PTSA functionalized Pt nanocomposites could be used as stable photocatalysts for photoinducing H2 evolution. At the optimal reaction conditions (nPt:nPTSA=100, pH 3), enhanced amounts of hydrogen were evolved from the system under UV/vis irradiation in the absence of an electron mediator. The corresponding amount of hydrogen evolution was 125.1 μmol for 12 h exposure to UV/vis irradiation, and the apparent quantum efficiency at a wavelength of λ=365 nm was 11.5 %. Dressed up for the photoshoot: A stable and efficient homogeneous catalytic system involving 1,3,6,8‐pyrenetetrasulfonic acid (PTSA) functionalized Pt nanocomposites as photocatalysts and ethylenediaminetetraacetic acid (EDTA) as a sacrificial reductant in the absence of an electron mediator was prepared.