An Overview of the Photocatalytic Water Splitting over Suspended Particles

The conversion of solar to chemical energy is one of the central processes considered in the emerging renewable energy economy. Hydrogen production from water splitting over particulate semiconductor catalysts has often been proposed as a simple and a cost-effective method for large-scale production. In this review, we summarize the basic concepts of the overall water splitting (in the absence of sacrificial agents) using particulate photocatalysts, with a focus on their synthetic methods and the role of the so-called co-catalysts. Then, a focus is then given on improving light absorption in which the Z-scheme concept and the overall system efficiency are discussed. A section on reactor design and cost of the overall technology is given, where the possibility of the different technologies to be deployed at a commercial scale and the considerable challenges ahead are discussed. To date, the highest reported efficiency of any of these systems is at least one order of magnitude lower than that deserving consideration for practical applications.

Automated summary

This review summarizes the basic concepts and synthetic methods of utilizing particulate semiconductor catalysts for water splitting to produce hydrogen, focusing on the role of co-catalysts and improving light absorption. It also discusses reactor design, overall technology costs, the potential for commercial-scale deployment of different technologies, and the significant challenges ahead. The highest reported efficiency of these systems to date is at least one order of magnitude lower than what is suitable for practical applications.