Enhanced Photocatalytic Hydrogen Evolution from Water Splitting on Ta2O5/SrZrO3Heterostructures Decorated with CuxO/RuO2Cocatalysts

Abstract

Photocatalytic H2generation by water splitting is a promising alternative for producing renewable fuels. This work synthesized a new type of Ta2O5/SrZrO3heterostructure with Ru and Cu (RuO2/CuxO/Ta2O5/SrZrO3) using solid-state chemistry methods to achieve a high H2production of 5164 μmol g-1h-1under simulated solar light, 39 times higher than that produced using SrZrO3. The heterostructure performance is compared with other Ta2O5/SrZrO3heterostructure compositions loaded with RuO2, CuxO, or Pt. CuxO is used to showcase the usage of less costly cocatalysts to produce H2. The photocatalytic activity toward H2by the RuO2/CuxO/Ta2O5/SrZrO3heterostructure remains the highest, followed by RuO2/Ta2O5/SrZrO3> CuxO/Ta2O5/SrZrO3> Pt/Ta2O5/SrZrO3> Ta2O5/SrZrO3> SrZrO3. Band gap tunability and high optical absorbance in the visible region are more prominent for the heterostructures containing cocatalysts (RuO2or CuxO) and are even higher for the binary catalyst (RuO2/CuxO). The presence of the binary catalyst is observed to impact the charge carrier transport in Ta2O5/SrZrO3, improving the solar to hydrogen conversion efficiency. The results represent a valuable contribution to the design of SrZrO3-based heterostructures for photocatalytic H2production by solar water splitting.