Influence of Copper as a Co-catalyst of Potassium Hexaniobate Nanotubes on the Photocatalytic Hydrogen Evolution from a Methanol Aqueous Solution

摘要

In the presence of Cu~(2+) ions, the photocatalytic hydrogen evolution from a methanol aqueous solution was achieved when potassium hexaniobate nanotubes were used as the catalyst. It was found that there existed a photo-induced period in the initial reaction stage. Furthermore, the photo-induced period was prolonged by increasing the amount of Cu~(2+) ions. After that, the rate of hydrogen evolution was dramatically improved. Combined with the reaction phenomena and the result of the photocatalytic hydrogen evolution, it was deduced that the Cu~(2+) ions captured the photo-generated electrons of potassium hexaniobate nanotubes in the photo-induced period. Consequently, the Cu~(2+) ions were reduced and deposited on the potassium hexaniobate nanotubes.