Construction of semiconductor heterojunctions can effectively accelerate the separation of photo-induced charge carriers and thereby enhance photocatalytic activity. Here, NiSe was used as an effective co-catalyst to construct an active NiSe/TiO2 heterojunction for improving the photocatalytic H-2 production of TiO2 . The resultant 10%NiSe/TiO2 heterojunction exhibited 11 times higher photocatalytic H-2-production activity than that of bare TiO2. The NiSe/TiO2 heterojunction and the photo-reduction of partial Ni2+ to Ni(0 )notably accelerated the separation and transfer of photo-excited electron-hole pairs, and thus resulted in obvious improvement of H-2-evolution activity. This work holds promise for the application of NiSe in photocatalysis as a high-efficiency photocatalytic cocatalyst. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.