Abstract Potassium hexatitanate has been barely studied as a photocatalytic material for the hydrogen production from water splitting. The aim is to synthesize and characterize K 2 Ti 6 O 13 fibers in order to evaluate their photocatalytic activity. Materials were characterized by XRD, BET, UV–Vis and SEM. Fibers were produced with sizes varying from 12 to 35 μm in length and 260–530 nm in diameter, as well as with a specific surface area of 4.1 m 2 /g and 2.3 m 2 /g for a heat treatment at 900 °C (C21) and 1000 °C (C22), respectively. Band gap energies for these titanates fall within the visible spectrum 3.23 eV (C21) and 3.28 eV (C22), respectively. Maximum hydrogen production was achieved by (C21) with 2387 μmolH 2 /gcat, while the lowest production was observed for sample (C22) with 1538 μmolH 2 /gcat at 8 h of irradiation. Crystals of K 2 Ti 6 O 13 exhibited high photocatalytic activity and they can be considered as potential photocatalysts for H 2 production.