A new system for the production of hydrogen, constructed using silica gel as a matrix, Eosin Y as a photosensitizer, and Pt as a cocatalyst, has been reported. It was found that the rate of photosensitized hydrogen evolution in the presence of silica gel is enhanced about 10-fold relative to the homogeneous phase, i.e. in the absence of silica gel. The pH value of the solution and the concentration of Eosin Y have remarkable effects on the rate of hydrogen evolution. The optimal pH and concentration of Eosin Y are 7 and 3.60 x 10(-4) mol dm(-3) (E/S = 1/3) to 7.24 x 10(-4) mol dm(-3) (E/S = 1/1), respectively. Triethanolamine (TEOA) as an electron donor, the rate of hydrogen evolution and the apparent quantum efficiency in the silica gel system under visible-light irradiation (lambda >= 420 nm) can reach about 43 mu mol h(-1) and 10.4%, respectively. In addition, the roles of silica gel, Pt and TEOA, respectively; and the probable mechanism of photosensitized hydrogen evolution have been discussed. (c) 2007 Elsevier B.V. All rights reserved.