Nanoscopic US 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 (lambda > 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 US in ETS-zeolites is effective for separating charge-carriers photogenerated in US and for improving the activity as well as the stability. (c) 2005 Elsevier B.V. All rights reserved.