Aurivillius compound Bi5Ti3CrO15 as a visible-light-active photocatalyst for hydrogen production from water

Layered Aurivillius compound Bi 5 Ti 3 CrO 15 has been synthesized by a hydrothermal method for the application as a photocatalyst to liberate hydrogen from water. Bi 5 Ti 3 CrO 15 owns a narrow band gap ( E g  ~2.46 eV) and shows stable photocatalytic activity under both full range ( λ  ≥250 nm) and visible light illumination ( λ  ≥420 nm). A short hydrothermal reaction time is critical to achieve high photocatalytic activity as defects such as Cr 6+ and Bi 5+ can be avoided. An AQE as high as 3.66% at 420 nm ± 20 nm has been recorded, warranting promising application in the field of solar energy conversions. DFT calculation reveals the important role of Cr 3+ cations for visible light sensitivity of Bi 5 Ti 3 CrO 15 .