Photocatalytic activity of CdS nanoparticles incorporated in titanium silicate molecular sieves of ETS-4 and ETS-10

Nanoscopic CdS particles were encapsulated into microchannels of Engelhard titanosilicates, ETS-4 as well as ETS-10, with the photocatalytically active -Ti-O-Ti- quantum wires in their frameworks. The photocatalytic activities for hydrogen production from water under visible light irradiation (λ > 420 nm) were investigated in the CdS/ETS system. A stable photocatalytic activity under visible light irradiation was found in an aqueous solution containing Na2S and Na2SO3 as electron donors. The results suggest that the encapsulation of CdS in ETS-zeolites is effective for separating charge-carriers photogenerated in CdS and for improving the activity as well as the stability.