Constructing Electron Transfer Bridge between Organometal Halide Perovskites and Noble Metal Cocatalyst for Enhanced Photocatalytic Hydrogen Production

Organometal halide perovskites (OMHPs) are attractive candidates for the photocatalytic hydrogen evolution reaction (HER), yet the poor contact between OMHPs and the HER cocatalysts, like benchmark noble metals, seriously restricts the interfacial charge transfer and therefore the photocatalytic activity. Herein, by using two-dimensional (2D) OMHP phenylmethylammonium lead iodide (PMA2PbI4) as an example, we present an “electron transfer bridge” design to address this issue. In this design, metal sulfides, like nickel sulfide (NiSx), were preassembled on the surface of PMA2PbI4 via a facile adsorption approach. Benefiting from the strong chemical interaction between PMA2PbI4 and NiSx and the favorable electron-extraction ability of NiSx, the photogenerated electrons can efficiently transfer from OMHPs to NiSx. The electron-rich NiSx particles can then behave as the active sites for the following photodeposited Pt cocatalyst, which allows the efficient consumption of the photogenerated electrons to produce H2. Therefore, the sandwich-like architecture of the Pt-NiSx/S-PMA2PbI4 can leverage the high electron-extraction capability of NiSx and the efficient HER catalytic activity of Pt simultaneously, liberating the potential of PMA2PbI4 for photocatalytic HER. A photocatalytic HER activity of 693.2 μmol·h–1 was achieved with the optimum Pt-NiSx/S-PMA2PbI4, which is ca. 39 times that of PMA2PbI4. An apparent quantum efficiency of 25.1% at 450 nm was obtained, representing one of the highest values reported for 2D OMHPs.