Enhancing photoelectrocatalytic water splitting performance through PdCoP co-modification of Ti:Fe2O3.

α-Fe 2 O 3 has been regarded as an ideal n-type photoanode material due to its exceptional stability, environmental friendliness, optimal band structure (1.9∼2.2 eV), and valence band position (approximately 2.3 V). However, α-Fe 2 O 3 still faces challenges such as low absorption coefficient, poor conductivity, short carrier lifetime, low carrier mobility, facile recombination of photogenerated charges, and sluggish kinetics of water oxidation. To address these issues comprehensively and effectively, this study initially synthesized Ti-doped Fe 2 O 3 nanorods through doping and hydrothermal methods. Subsequently, a PdCoP amorphous layer was deliberately fabricated on the Ti:Fe 2 O 3 nanorods (TF) photoelectrode through facile solution impregnation and phosphorization treatment. The experimental results demonstrate that Ti doping effectively enhances carrier separation, leading to a photocurrent of 0.52 mA cm−2 at 1.23 V RHE , which is 2.08 times higher than the undoped counterpart. Moreover, upon further modification with the PdCoP amorphous layer, the photocurrent density of PdCoP/TF photoanode significantly increases under illumination, reaching 2.82 mA cm−2 at 1.23 V RHE , which is 11.28 times higher than pure Fe 2 O 3. Density functional theory (DFT) calculations performed at the interface between the amorphous layer and substrate indicate that surface modification of PdCoP on TF alters its surface electronic structure while reducing the energy barrier for oxygen evolution reaction (OER), thereby enhancing its performance in photoelectrochemical water splitting. [Display omitted] • The electronic structure of α-Fe 2 O 3 is optimized through Ti doping and modification of the amorphous layer. • The PdCoP/TF photoanode exhibits high efficiency in converting solar energy. • Revealing the active sites and mechanisms for water splitting through DFT calculations. [ABSTRACT FROM AUTHOR]