Tungsten-based oxide semiconductors for solar hydrogen generation

In this focused review the progress achieved in solar water splitting over tungsten based oxide photocatalysts is summarized. Beyond simple doping of WO3, both binary and ternary oxides are discussed, presenting the various synthesis methods and resulting crystal structures. Theoretical considerations on the band structure are also given including a perspective on possible strategies for band engineering. The effectiveness of such strategies for designing tungsten-based oxide semiconductors as robust photocatalysts for stoichiometric solar water splitting, is reviewed. In addition, progress on Z-scheme based strategies using combined photocatalysts, where WO3 is responsible for water photooxidation (O2-evolution) while H2 generation takes place on its counterpart, is also reviewed.