Rhodium was reported to be an essential component of the efficient cocatalyst (Rh2-xCrxO3 or core/shell of Rh@Cr2O3) on GaN-ZnO for photocatalytic overall water splitting (POWS). Herein we demonstrate that the Rh can be replaced by less-expensive Pd deposited via atomic layer deposition and together with photodeposition of Cr2O3 shell, a comparable activity in POWS can be achieved even with much less Pd loading than Rh in Rh2-xCrxO3/GaN-ZnO under the same reaction conditions. [GRAPHICS]