Modification of Ti‐Fe ₂ O ₃ with Basic Bismuth Nitrate Passivating Layer to Improve the Photoelectrochemical Water Splitting Performance

Hematite (α‐Fe 2 O 3 ) serves as an excellent photoanode for solar‐driven water oxidation. However, its photoelectrochemical (PEC) performance is severely constrained by the pronounced poor electrical conductivity, low charge carrier mobility, short hole diffusion length, and rapid charge recombination. Herein, α‐Fe 2 O 3 is modified through Ti doping, the introduction of surface passivation layer of basic bismuth nitrate (BBN), and the loading of Ti‐FeOOH cocatalyst. The incorporation of Ti increases the carrier concentration and improves conductivity. The BBN crystals play a role in passivating the surface states. When Ti‐FeOOH cocatalyst is loaded, the obtained photoanode Ti‐FeOOH/Bi/Ti‐Fe 2 O 3 achieves a photocurrent density of 1.83 mA cm −2 , which is 5.7 times that of the pristine α‐Fe 2 O 3 photoanode. This study has positive guiding significance for the modification of α‐Fe 2 O 3 photoanode by multiple strategies.