An organo-templated titanium-oxo sulfate of the formulation (H(2)nep)[TiO(SO4)(2)] (denoted as TiOS, nep = N-ethylpiperazine) was synthesized under solvent-free conditions. The framework of TiOS is assembled from the [TiO(SO4)(2)](n)(2n-) infinite chains interconnected by the H(2)nep cations through H-bond networks. After thermal treatment under vacuum conditions, the organic template H(2)nep was partially decomposed and converted into N-doped carbon dots (N-CDs), resulting in the N-CDs@TiOS composite material with retained crystallinity of the parent TiOS. The thermolysis of organic templates generates meso-cavities in the framework, rendering N-CDs@TiOS with a mesoporous structure. Photoelectrochemical and photocatalytic experiments show that the presence of N-CDs substantially improved visible-light-driven photocatalytic activity of N-CDs@TiOS compared to that of TiOS. The template thermolysis strategy gives an effective approach to construct the CDs-sensitized Ti-based mesoporous open-framework materials for visible-light photocatalytic applications.