Part I: Basic Principles: Introduction.- Principles of Photoelectrochemical Cells.- Photoelectrochemical Measurements.- Part II: Materials Properties and Synthesis: Nanostructured α-Fe2O3 Photoanodes.- Mixed Metal Oxide Photoelectrodes and Photocatalysts.- Combinatorial Identification and Optimization of New Oxide Semiconductors.- Part III: Devices and Device Characterization.- Multijunction Approaches to Photo-electrochemical Water Splitting.- Part IV: Future Perspectives.- Economic and Business Perspectives.- Emerging Trends in Water Photoelectrolysis.