It is highly desirable to combine the microstructure management and heterostructure construction technique to remold inherent wide band gap semiconductor CaTiO3 with the purpose of enhancing its visible light absorption capacity and photocatalytic performance. Herein, a novel multi-shelled hollow cube Bi12O17Cl2/CaTiO3 heterostructure has been successfully synthesized by a facile template-free method for photocatalytic hydrogen production and degradation pollutants in water under the visible light. The investigations of microstructure, physicochemical property and photoelectric behaviors indicate that the multi-shelled hollow cube architecture and synergetic effect of 2D-3D structural coupling are dominant reasons to enhance phototcatalytic performance, which can significantly improve the absorption and utilization of visible light, multiply abundant active radical generation and boost the separation and migration efficiency of photoproduced electron-hole pairs. Moreover, the probable photocatalytic reaction mechanisms, the feasible migration behaviors of photo-produced charges, the influence factors of enhancing photocatalytic activities are proposed in depth. It is intended that further innovative works on the multi-shelled hollow cube architecture design of high-performance photocatalyst by facile template-free hydrothermal method can be inspired. (C) 2020 Elsevier Inc. All rights reserved.