Improving the photocatalytic H2 evolution activities of TiO2 by modulating the stabilizing ligands of the nanoscale Ti8O8-cluster precursors

Titanium-oxo clusters (TOCs) are important model complexes and potential precise single source precursors of TiO2 materials. We report here a series of TiO2 samples derived from TOCs with the same wheel-like Ti8O8 clustercore but different stabilizing ligands. Our results demonstrate that the ligands on TOCs not only influence the phase-transition during themolysis, but more importantly tune the photocatalytic H-2 evolution activities of the obtained' TiO2 materials. Through 500 degrees C calcination, the nanosized Ti8O8 cluster stabilized by organic benzoate ligands gives rise to a TiO2 sample with H-2 production rate of 611 mu mol/h/g. When the stabilizing ligands are changed to inorganic SO42- a significant improvement of H-2 evolution activity has been achieved, resulting in a 7-times higher value of 4527 mu mol/h/g. This work provides a new strategy to produce TiO2 with enhanced and tunable photocatalytic activities from titanium-oxo cluster precursors. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.