2012-02-05Hydrogen technology meets nanotechnology |
Nanorods are composed of three segments: Pt nanoparticle, CdS single-crustal nanowire and ZnSe nanoparticle. Such nanorods are used for light energy harvesting through photocatalytic hydrogen production.Light-harvesting technology is of importance today due to the high interest to renewable energy sources. The sun provides us with a strong a steady flux of 6000 K photons. Harvesting this energy is a promising direction in solving every increasing usable energy demands. One way to achieve such harvesting is to use the photons to split water molecules and release hydrogen from them. Water of course is not a fuel, but hydrogen is an excellent and clean fuel.
Now a research team led by M. Zamkov of Bowling Green State University demonstrates hydrogen production using nanorods produced by means of nanotechnology. The group synthesized nanorods which are composed of three segments, namely a Pt nanoparticle, a CdS single-crustal nanowire and ZnSe nanoparticle, as shown in the figure. The scientists achieve efficient and stable reduction of water by such composed nanorods. The team finds that the hydrogen production on Pt sites is efficient only when electron donating molecules are employed to stabilize semiconductor surfaces.
A problem that remains to be solved is the degradation of nanorods. The life span of ZnSe/CdS/Pt photocatalysts in hydrogen production experiments was about six hours. The degradation is explained by the decomposition of some
components of the photocatalytic assembly. The degradation
mechanism is not well understood yet. A corrosion of the sulfide by oxidizing holes is a possibility. The team will continue investigations into the efficiency and stability of the composite nanorods.
Journal reference: Nano Lett., vol.11, pp 2919–2926 (2011)
Source: Nano Letters
Hydrogen technology meets nanotechnology
