Synthesis, characterization and photocatalytic evaluation of potassium hexatitanate (K_2Ti_6O_(13)) fibers

摘要

Potassium hexatitanate has been barely studied as a photocatalytic material for the hydrogen production from water splitting. The aim is to synthesize and characterize K2Ti6O13 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 mu m 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 degrees C (C21) and 1000 degrees 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 mu molH(2)/gcat, while the lowest production was observed for sample (C22) with 1538 mu molH(2)/gcat at 8 h of irradiation. Crystals of K2Ti6O13 exhibited high photocatalytic activity and they can be considered as potential photocatalysts for H-2 production. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.