Novel NiO-modified Cu2O photocathode for photoelectrochemical water splitting

A novel ITO/NiO/Cu2O structure served as photocathodes was applied in photoelectrochemical (PEC) water splitting for the first time. The NiO integration is found to slightly ameliorate the crystalline structure of Cu2O. PEC measurements showed that NiO-modified Cu2O photocathodes can deliver a higher PEC performance, as the photocurrent density was up to − 1.68 mA/cm2 at − 0.6 V versus RHE under simulated AM 1.5G illumination, which is 2.8 times higher than that of nude one. The enhanced PEC performance may come from the improved charge separation and migration properties of NiO modification.