Ultimate Energy Dream of Human Beings: Photocatalytic Water Splitting for Hydrogen Production by Using Solar Energy

Hydrogen production based on photocatalytic water splitting driven by sunlight is able to directly provide high-power energy from the solar energy, which is considered to be the ultimate energy dream of human being. The basic principle of photocatalytic water splitting is presented, and the thermodynamic and kinetic requirements for photocatalytic materials are outlined. Four important strategies to achieve efficient photocatalytic water splitting are discussed; these strategies include the research and development of novel photocatalysts, the construction of cocatalytic system, the modification of nanoscale morphology and structure, and the design of integrated devices. Correspondingly, the recent research progress in the key photocatalytic materials and technologies is summarized. For each strategy, the factors affecting photocatalytic performances as well as the remainder challenges are also presented. In terms of practical applications, the photocatalytic hydrogen generation system is also surveyed by introducing the sacrificial reagent employment, the artificial photosynthesis, the photolysis of seawater, and the photocatalyst stability. Finally, the development direction of photocatalytic technologies for hydrogen production based on water splitting is predicted.