Enhanced Photocatalytic Hydrogen Evolution from Water Splitting on Ta(2)O(5)/SrZrO(3) Heterostructures Decorated with Cu(x)O/RuO(2) Cocatalysts

[Image: see text] 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.