Development of photoelectrodes capable of efficiently degrading fluorinated pollutants with C-F bonds remains a significant challenge in the photoelectrocatalytic (PEC) system. Herein, a nanoneedle CoOOH-loaded nanoplate WO3 photoelectrode (CoOOH/WO3) was successfully fabricated, which exhibited a high rate of 3.92 × 10−2 min−1 in the PEC degradation of 4-fluorophenol, much higher than that of pristine WO3. The ∙OH generation rate by CoOOH/WO3 was 1.5 times that by WO3. Photoelectric features demonstrated that an interfacial internal-electric field provided a driving force for efficient charge separation in the CoOOH/WO3; Density functional theory calculations demonstrated that constructing CoOOH onto WO3 reduced thermodynamic barriers for H2O oxidation and for *OH formation, thereby promoting the ∙OH generation; Computational fluid dynamic simulations confirmed the facilitated surface reactions and intensified contact between pollutants and ∙OH. This study provided viable insights into simultaneously improving the charge separation efficiency, surface H2O oxidation kinetic and physical contact in PEC wastewater treatment.