Photocatalysis inorganic reduction

Chapter 2 considers the removal of inorganic water contaminants using photocatalysis. Metal cations react via one-electron steps first leading to unstable chemical intermediates, and later to stable species. Three possible mechanisms are identified (a) direct reduction via photo-generated conduction band electrons, (b) indirect reduction by intermediates generated from electron donors, and (c) oxidative removal by electron holes or hydroxyl radicals. The provided examples show the significance of these mechanisms for the removal of water contaminants such as chromium, mercury, lead, uranium, and arsenic. 

Finally, Chapter IX, discusses recent research on the concurrent oxidation-reduction of organic and inorganic compounds and on the inactivation of model microorganisms. These two applications of photocatalysis have the potential of significantly improving the prospects for this novel technology. 

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