An efficient photoelectrochemical water-splitting process is of paramount importance as it provides a sustainable and clean method for generating hydrogen fuel, which is crucial for addressing the world’s growing energy needs while mitigating environmental concerns. Herein, the effects of applying a magnetic field on the photoelectrochemical performance of photoanodes composed of Cobalt ferrite (CoFe2O4) and Manganese (Mn)-doped CoFe2O4 are investigated. The CoMnxFe2-xO4 nanoparticles were synthesized using a sol–gel method, with varying values of x (0.0, 0.1, 0.3, and 0.5). X-ray diffraction analysis consistently reveals a singular cubic spinel structure for all four samples. Magnetic analyses demonstrate an enhancement in magnetic characteristics, including saturation magnetization, coercivity, and anisotropy field in the CoMn0.3Fe1.7O4 sample compared to the other three samples. Photoelectrochemical (PEC) measurements indicate that the photocurrent increases in all four samples when a static magnetic field is applied. However, the CoMn0.3Fe1.7O4 sample shows a more pronounced enhancement. Specifically, the dark current density increases by more than 115 % when a magnetic field of 190 ± 20 mT is applied. Additionally, it rises by 387 % under light illumination with the magnetic field. This enhancement in PEC performance is attributed to electron spin polarization adjusted through the external magnetic field.
