Convegni ATI - Accesso riservato soci CTI

Autore: P.L. Gentili, F. Ortica, F. Elisei, M. Giuliobello

Collana: CA - 61 - Perugia 2006

Note:
In this work, some strategies to exploit the visible portion of solar spectrum in order to photosynthesize hydrogen from water are presented. To split water and develop hydrogen, the choice of an appropriate photo-catalyst is needed. A visible-lightdriven photo-catalyst through doping of foreign elements into semiconductors with large band gaps or preparing solid solutions of semiconductors having different band gaps can be designed. Alternatively, one can coat a semiconductor absorbing only UV radiation with dye-molecules acting simply as sensitizers of the photosynthetic process. Finally, the action of up-converters so as not to waste electromagnetic radiation of low frequency will be exploited.
Furthermore, if these different kinds of materials are prepared with nanometric sizes, they allow some improvements in the different steps of the photo-catalytic process. Nano-particles assure an increase in the efficiency of electron-hole pair separation respect to bulk materials, a shortening in the electron-hole diffusion length and an extension of the interfacial surface area.