As the performance of photoelectrodes used in in a photoelectrochemical cell (PEC) for water splitting continues to improve, concurrently improving their photostabilities has become an important issue. In this presentation, we report a new strategy to suppress photocorrosion of photoelectrodes using a BiVO₄ photoanode as an example. BiVO₄ has been recently identified as a promising oxide-based photoanodes for solar water splitting owing to many of its uniquely advantageous features. Anodic photocorrosion of BiVO₄ photoanodes involves the loss of V⁵⁺ from the BiVO₄ lattice by dissolution. Any composition change caused by the anodic photocorrosion of BiVO₄ must be coupled with the oxidation of one or more of the elements present in BiVO₄. Since V⁵⁺ in the BiVO₄ lattice cannot be further oxidized, the dissolution of V⁵⁺ must be linked with the photooxidation of Bi³⁺ and/or lattice O^2- ions. We show that the use of a V⁵⁺-saturated electrolyte, which inhibits the photooxidation-coupled dissolution of BiVO₄, can slow down the rate of photocorrosion considerably and serve as a simple yet effective method to suppress anodic photocorrosion of BiVO₄. We also discovered that the V⁵⁺ species in the solution can incorporate into the oxygen evolution catalyst (OEC) layer present on the BiVO₄ surface during water oxidation, further enhancing water oxidation kinetics. The effect of the V⁵⁺ species in the electrolyte on both the long-term photostability of BiVO₄ and the performance of the OEC layer will be discussed in detail.