The visible light photoassisted production of hydrogen from methanol-water solutions containing mixtures of small particles of CdS/SiO2 and a platinized wide-band-gap semiconductor (TiO2, ZnO, SnO2, or WO3) separately supported on silica was studied. The activity is higher for these separately supported particles than for samples prepared by depositing the active materials together on the silica particles. The efficiency of hydrogen production is not dependent on the energy of the conduction band of the wide-band-gap metal oxide. Hence, we conclude that electron injection from the conduction band of CdS into the conduction band of the metal oxide is not an important pathway for charge transport to the Pt particles. These oxides do improve the hydrogen production activity of the platinum formed during photoplatinization. CdS/SiO2 particles attach to pellets of the platinized oxide and we propose on this basis that agglomeration of the separate oxide- and sulfide-containing particles is important for photoassisted hydrogen production.
|Original language||English (US)|
|Number of pages||5|
|Journal||Journal of physical chemistry|
|State||Published - Dec 1 1987|
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry