An efficient and robust p-type NiO/Cu2O nanocomposite was developed as photocathodic catalyst of a photoelectrochemical cell. The nanocomposite with heterojunction demonstrates enhanced photoelectrochemical (PEC) properties and considerable photocatalytic hydrogen generation ability. When ca. 6 wt.% Cu2O was loaded on the surface of NiO, the sample exhibited the highest photocatalytic activity. The amount of hydrogen evolved from the cathodic chamber of the PEC cell up to 17.6 mu mol under 2 h simulated sunlight irradiation with -0.0455 V vs. RHE (reversible hydrogen electrode) bias. (C) 2018 Elsevier B.V. All rights reserved.