Black phosphorus: A promising two dimensional visible and near-infrared-activated photocatalyst for hydrogen evolution

- 2D black phosphorus (BP) nanoflakes with a broad spectrum are synthesized.
- BP/Pt/RGO nanoflakes harness visible and NIR light for photocatalytic H2 evolution.
- AQEs are as high as 8.7% at 420 nm (visible) and 1.5% at 780 nm (NIR).
- BP/Pt/RGO acts as visible and NIR-driven photocatalyst in solar energy conversion.

The search for active photocatalysts that directly split water to hydrogen (H2) under visible and near-infrared (NIR) light irradiation remains one of the most challenging tasks for solar energy utilization. Here we report that two dimensional (2D) black phosphorus (BP) nanoflakes can harness visible and NIR light for H2 evolution. In the presence of reduced graphene oxide and Pt nanoparticles, ca. 5.13 and 1.26 μmol H2 were obtained after excited BP nanoflakes under >420 nm and >780 nm irradiation for 4 h, respectively. The apparent quantum efficiencies (AQEs) were as high as approximately 8.7% at 420 ± 5 nm (visible) and 1.5% at 780 ± 5 nm (NIR), respectively. These results indicate that 2D BP can be used as visible- and NIR-activated elemental photocatalyst in artificial photosynthesis and renewable energy conversion.

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