Enhanced Photocatalytic Hydrogen Evolution from Water Splitting on Ta2O5/SrZrO3 Heterostructures Decorated with CuxO/RuO2 Cocatalysts

Photocatalytic H 2 generation by water splitting is a promising alternative for producing renewable fuels. This work synthesized a new type of Ta 2 O 5 /SrZrO 3 heterostructure with Ru and Cu (RuO 2 /Cu x O/Ta 2 O 5 /SrZrO 3 ) using solid-state chemistry methods to achieve a high H 2 production of 5164 μmol g –1 h –1 under simulated solar light, 39 times higher than that produced using SrZrO 3 . The heterostructure performance is compared with other Ta 2 O 5 /SrZrO 3 heterostructure compositions loaded with RuO 2 , Cu x O, or Pt. Cu x O is used to showcase the usage of less costly cocatalysts to produce H 2 . The photocatalytic activity toward H 2 by the RuO 2 /Cu x O/Ta 2 O 5 /SrZrO 3 heterostructure remains the highest, followed by RuO 2 /Ta 2 O 5 /SrZrO 3 > Cu x O/Ta 2 O 5 /SrZrO 3 > Pt/Ta 2 O 5 /SrZrO 3 > Ta 2 O 5 /SrZrO 3 > SrZrO 3 . Band gap tunability and high optical absorbance in the visible region are more prominent for the heterostructures containing cocatalysts (RuO 2 or Cu x O) and are even higher for the binary catalyst (RuO 2 /Cu x O). The presence of the binary catalyst is observed to impact the charge carrier transport in Ta 2 O 5 /SrZrO 3 , improving the solar to hydrogen conversion efficiency. The results represent a valuable contribution to the design of SrZrO 3 -based heterostructures for photocatalytic H 2 production by solar water splitting.