Progress in designing effective photoelectrodes for solar water splitting

Abstract Photoelectrochemical (PEC) water splitting process is regarded as a promising route to generate hydrogen by solar energy and at the heart of PEC is efficient electrode design. Great progress has been achieved in the aspects of material design, cocatalyst study, and electrode fabrication over the past decades. However, some key challenges remain unsolved, including the most demanded conversion efficiency issue. As three critical steps, i.e. light harvesting, charge transfer and surface reaction of the PEC process, occur in a huge range of time scale (from 10−12 s to 100 s), how to manage these subsequent steps to facilitate the seamless cooperation between each step to realize efficient PEC process is essentially important. This review focuses on an integral consideration of the three key criteria based on the recent progress on high efficient and stable photoelectrode design in PEC. The basic principles and potential strategies are summarized. Moreover, the challenge and perspective are also discussed.