The creation of photocatalysts with controlled facets has become an important approach to enhance their activity. Cu2O octahedra formed entirely with {1 1 1} surfaces are more efficient for photocatalysis reactions than nanosphere. Core@shell structured Cu2O@g-C3N4 octahedra photocatalyst was prepared by a combined solvothermal and chemisorption method. Moreover, the Cu2O@g-C3N4 composites exhibit superior activity for H-2 production to pure Cu2O crystals and g-C3N4 nanosheets. The enhanced photocatalytic activity can be mainly attributed to a synergistic effect at the interface of the Cu2O octahedra and g-C3N4 including large contact area, energy band structure and enhanced charge separation properties. Interestingly, the hybrid core@shell octahedra possess high photostability. Our results provide a new approach for the rational design and development of graphitic carbon nitride composites and open the way to a range of important applications of crystal-facet-dependent materials. (C) 2015 Elsevier B.V. All rights reserved.