Ultra-Thin Red Phosphor Nanosheets as an Efficient Photocatalyst for Hydrogen Evolution Under Visible Light

As a photocatalyst responding to visible light, red phosphorus has the advantages of cheap and easy availability, low toxicity and suitable band gap. In this work, ultra-thin red phosphorus (URP) with the narrower band gap through ultrasound for 8 h was successfully synthesized. Though a series of characterization (such as: XPS analysis, photoelectric response analysis, Raman analysis, AFM images, etc.), the narrow band gap and ultra-thin nanosheet structure could promote the generation of more photogenerated electrons and effectively improve the separation rate of photogenerated charges for highly efficient hydrogen evolution. URP showed the excellent photocatalytic hydrogen production without any cocatalysts (0.55 mmol g(-1) h(-1)), which was 2.88 times for untreated red phosphorus. In addition, URP overcame the limited stability and decreased the band gap of red phosphorus, producing hydrogen at a rate of 0.16 mmol g(-1) h(-1) after three cycles. This readily available and ultra-thin material can be used as a substrate material for other materials due to its similar graphene thickness.