Two-dimensional titania nanosheets have been utilized to fabricate 2D titania-based mesoporous silica through a controlled sol-gel method, which can further serve as a robust and versatile template to construct various 2D heterostructures via a nanocasting technology. 2D titania-based CdS has been fabricated. This heterostructure manifests an excellent H-2-production rate of 285 mu mol.h(-1) under visible-light irradiation and an apparent quantum yield of 6.9% at 420 nm.