Photoelectrochemical water splitting at titanium dioxide nanotubes coated with tungsten trioxide

The photocatalytic splitting of water into hydrogen and oxygen using solar light is a potentially clean and renewable source for hydrogen fuel. Titanium oxide nanotubes coated with tungsten oxide were prepared to harvest more solar light for the first time and characterized their water splitting efficiency. The tungsten trioxide coatings significantly enhanced the visible spectrum absorption of the titanium dioxide nanotube array, as well as their solar-spectrum induced photocurrents. For the sample, upon white light illumination at $150\mathrm{mW}∕{\mathrm{cm}}^2$ , hydrogen gas generated at the overall conversion efficiency of 0.87%.