A modified sol–gel technique with the aid of a structure-directing surfactant was employed to synthesize highly crystalline mesoporous-assembled V 2O 5 nanosheet under mild conditions. The synthesized V 2O 5 nanosheet was systematically characterized by TG-DTA, XRD, N 2 adsorption–desorption, high resolution TEM, and UV–visible spectroscopy analyses. The characterization results revealed that the synthesized V 2O 5 nanosheet exhibited not only high crystallinity but also narrow pore size distribution in the mesoporous range. The photocatalytic H 2 production activity of the synthesized mesoporous-assembled V 2O 5 nanosheet from both self photoexcitation and dye photosensitization systems under visible light irradiation was also found to be higher than that of a commercially available V 2O 5 powder.