Metal–Organic Frameworks for Photocatalytic Water Splitting

Various photocatalysts have been developed for photocatalytic water splitting—one of the most important processes that produces dihydrogen as clean energy for fuel cells. The successful achievements for this application are based mainly on transition metal oxides and some metal sulfides/nitrides. Recently, metal–organic frameworks (MOFs), a class of hybrid functional materials comprising organic backbone tethered infinitively in limitless way by metal‐oxide clusters, both of which can be customized accurately at the molecular level for targeted applications, have been able to photocatalytically degrade water. Herein, it is first aimed to comprehensively review fundamentals of water splitting catalyzed by semiconductor photocatalysts, which casts light on understanding of challenges in this area, thus providing strategies for development, if not rational design, of visible‐light‐driven MOFs that are capable of degrading water to hydrogen and oxygen. The recent advancements of using MOF photocatalysts for water splitting are further described in a way that benchmark achievements and limitations are considered so that the readers can imagine the big picture in this field and pay considerable attention to future solutions.