Effect of synthesis atmosphere on photocatalytic hydrogen production of NaNbO3

The NaNbO3 photocatalysts were prepared under air, H-2/Ar and O-2 atmosphere by a solid state reaction. These samples were characterized by X-ray diffraction, UV-vis spectroscopy, Raman spectroscopy, scanning electron microscopy and X-ray photoelectron spectroscopy. The photocatalytic activity of NaNbO3 samples were evaluated from the hydrogen evolution from an aqueous methanol solution. The hydrogen evolution rate of NaNbO3 under air, H-2/Ar and O-2 atmosphere showed an increasing trend in turn. Moreover, the hydrogen evolution rate exhibited a linear increase with the surface oxygen defects. (C) 2014 Elsevier B.V. All rights reserved.