Dual‐Interface Kinetics Activation Through Dipole‐Induced Dynamic Liquid Crystal Interfacial Engineering for Efficient Solar Water Splitting

Interface engineering is vital for improving the efficiency of semiconductor‐based solar energy devices. Herein, we report a dipole‐induced dynamic interface engineering strategy enabled by the nematic phase of 2‐(4‐((4‐(heptyloxy)phenyl)ethynyl)phenyl)‐5‐methylbenzo[ d ]oxazole (PEMB‐N) liquid crystal molecules. The rationally designed BiVO 4 /PEMB‐N/FeNiOOH photoanode achieves a photocurrent density of 6.4 mA/cm 2 at 1.23 V vs. RHE, alongside a solar‐to‐hydrogen (STH) conversion efficiency of 7.2% and sustained photostability. A combination of density functional theory (DFT) calculations and experimental characterizations (in situ UV/vis spectroelectrochemistry and Kelvin probe force microscopy) elucidates that the enhanced dipole moment arising from benzoxazole functionalization, coupled with the dynamically tunable nematic phase of PEMB‐N, facilitates the directional and multichannel extraction and migration of holes across the BiVO 4 /PEMB‐N interface. Furthermore, at the PEMB‐N/FeNiOOH interface, the well‐ordered nematic phase effectively modulates the Fe d‐band center and boosts the oxygen evolution reaction (OER) kinetics. Importantly, this strategy is universally applicable to Ti‐Fe 2 O 3 /PEMB‐N/FeNiOOH photoanodes, demonstrating its broad compatibility with different photoanodes. These findings provide a “soft” interface engineering concept compared to conventional “rigid” interface modulation strategies for constructing high‐performance solar‐driven water splitting systems.