Challenges for photocatalytic overall water splitting

Summary

The hydrogen economy is a sunrise industry, which is considered the ultimate solution to power the future society. Photocatalytic overall water splitting is projected as a potential technology for H₂ production. However, its performance is still far from meeting the criteria for large-scale production. This paper argues that photocatalytic overall water splitting is theoretically and practically hard to achieve. The limiting factors, including unfavorable thermodynamics, slow kinetics, dissolved oxygen, and rapid backward reaction, are discussed. This paper is expected to give readers a better understanding of the photocatalytic overall water splitting and analyze the associated challenges in every subtle aspect.