Semiconductor Photocatalysts Based on Nanostructured Cd1 − xZnxS Solid Solutions in the Reaction of Hydrogen Evolution From Aqueous Solutions of Inorganic Electron Donors Under Visible Light

The rapid depletion of hydrocarbon resources makes it necessary to harness a wide range of new chemical energy carriers and alternative or unconventional sources of energy. Particular attention is paid to the use of hydrogen as a fuel. Visible light-driven hydrogen production from aqueous solutions of Na₂S/Na₂SO₃ over suspended semiconductor CdS-based photocatalysts is considered as promising method for the conversion of solar energy to the energy of chemical bonds. In this chapter the main approaches to the increase of cadmium sulfide photocatalytic activity were observed. It has been shown that composite photocatalysts based on Cd_1-xZn_xS loaded with a metallic cocatalyst are very active in the visible light-driven hydrogen production from aqueous sulfide-sulfite solutions. The fact that transition metal compounds including copper and nickel rather than noble metals have been used as cocatalysts with increasing frequently is of great importance. Great potential for practical application of photocatalytic hydrogen production from aqueous suspensions of inorganic electron donors over Cd_1-xZn_xS with cocatalysts based on nonnoble metals is confirmed by the apparent quantum efficiency up to 23% upon irradiation with the visible light.