Highly ordered mesocrystalline semiconductors often indicate tremendous prospects in the clean energy production and environmental photocatalysis mainly because of their unique superstructure for efficient charge transport pathways and long-lived charges. Here, superstructure Ta3N5 mesocrystals with the high-energy surface {2 0 0} planes exposed were the first time to be successfully fabricated by topological transformation of Ta2O5 mesocrystals. The prepared Ta3N5 mesocrystals showed enhanced visible-light photocatalytic hydrogen production activity of 98.67 mu mol g(-1) for 180 min irradiation, which was approximately 5.28 times that of comm-Ta3N5 prepared with commercial Ta2O5 as the starting material, mainly due to the formation of long-distance electron conduction pathways and long-lived charges. The detailed electronic band structures of the prepared Ta3N5 mesocrystals were also investigated by electrochemical method. Finally, possible visible-light photocatalytic mechanisms of Ta3N5 mesocrystals for enhanced hydrogen production was also proposed in detail. Current work also indicates that tantalum-based mesocrystals show great potential to enhance the charge separation for efficient photocatalytic water splitting. (C) 2019 Elsevier Inc. All rights reserved.