Activation of Water‐Splitting Photocatalysts by Loading with Ultrafine Rh–Cr Mixed‐Oxide Cocatalyst Nanoparticles

The activity of many water‐splitting photocatalysts could be improved by the use of RhIII–CrIII mixed oxide (Rh2−xCrxO3) particles as cocatalysts. Although further improvement of water‐splitting activity could be achieved if the size of the Rh2−xCrxO3 particles was decreased further, it is difficult to load ultrafine (
Rh2−x Cr x O3 particles with a size of approximately 1.3 nm were loaded onto a BaLa4Ti4O15 photocatalyst. The photocatalyst exhibited the highest quantum yield reported for BaLa4Ti4O15. The developed preparation technique of Rh2−xCrxO3 particles is also expected to improve the activity of other advanced water‐splitting photocatalysts. SG=glutathionate.