Over the past decades, various photocatalysts have been developed and great progress has been achieved in the field of solar-driven photocatalytic water splitting. However, the lack of an accurate and comprehensive evaluation method greatly hinders the meaningful comparison between different systems and becomes a serious impediment for the development of photocatalysts. Although many researchers are aware of this, there has been little work in this area. In this Viewpoint, we first analyze the insufficiencies of the existing evaluation methods and then make preliminary suggestions, aiming to stimulate discussion in the research community and hopefully lead to a widely accepted and authoritative evaluation system to assess photocatalyst performance.
