Comparative investigation of hydrogen production over Ag-, Ni-, and Cu-loaded mesoporous-assembled TiO2-ZrO2 mixed oxide nanocrystal photocatalysts

This work focused on the enhancement of photocatalytic hydrogen production activity under UV light irradiation of mesoporous-assembled 0.93TiO(2)-0.07ZrO(2) mixed oxide nanocrystal photocatalysts (having the TiO2-to-ZrO2 molar ratio of 93:7) by non-precious metal (Ag, Ni, and Cu) loadings via a photochemical deposition method. The mesoporous-assembled 0.93TiO(2)-0.07ZrO(2) mixed oxide was synthesized by a sol-gel process with the aid of a structure-directing surfactant prior to the metal loadings. The prepared photocatalysts were characterized by N-2 adsorption-desorption, scanning electron microscopy, transmission electron microscopy, X-ray energy dispersive analysis, X-ray diffraction, UV-visible spectroscopy, and H-2 chemisorption. The most efficient loaded metal was found to be Cu due to its suitable physical, chemical, and electrochemical properties with the 0.93TiO(2)-0.07ZrO(2) mixed oxide-based photocatalyst. The 0.15 wt.% Cu-loaded 0.93TiO(2)-0.07ZrO(2) mixed oxide photocatalyst exhibited the highest photocatalytic hydrogen production activity with a hydrogen production rate of 12.8 cm(3) h(-1) g(cat)(-1). (C) 2011 Elsevier B.V. All rights reserved.