Exploring the hydrogen evolution reaction (HER) side of perovskite-based materials during photoelectrochemical water splitting

Solar energy-powered hydrogen (H2) production has emerged as a leading process for renewable energy transformation in our pursuit of a sustainable and reliable energy harvest process. Hydrogen is a chemical mediator that can convert otherwise intermittent and dilute renewables to electricity. This process is critical for decarbonizing our energy landscape while we minimize the adverse anthropogenic effects on our climate. The development of highly active and durable photocatalytic systems with extended light absorption in a broad solar spectrum is essential for this solar-to-hydrogen conversion. Perovskite oxides have attracted much attention as a common catalyst that not only absorbs sunlight, but also catalyzes water splitting to generate H2 from omnipresent water. The photo(electro)chemical hydrogen production by perovskites highlights their exceptional compositional flexibility, excellent electronic, optical, and magnetic properties, overall resistance to photo-corrosion, and good thermal stability. This chapter discusses the fundamental principles of solar-driven water splitting and the structure-functional properties of perovskite materials. The different routes of structural engineering of perovskite semiconductor oxides via selective element doping create new heterojunctions while boosting the overall catalytic performance and stability due to favorable surface modifications. Herein, an up-to-date discussion on the research progress in design, development, and application in HER has been summarized, emphasizing the relationship between the composition/structure and (photo)electrochemical activity.