Perovskite and layered perovskite oxynitrides for efficient sunlight-driven artificial synthesis

Perovskite and layered perovskite oxynitrides are regarded as promising visible-light-responsive semiconductors for efficient artificial photosynthesis to produce renewable value-added energy resources, including H2, formic acid (HCOOH), and ammonia (NH3). This is because of their chemical stability in aqueous electrolytes at various pH values, along with a narrow bandgap and a suitable band position bestowing ideal optical properties. In this review, we discuss recent advances in photocatalysis using perovskite and layered perovskite oxynitrides responsive to a wide wavelength range of the visible-light spectrum. Next, we address in detail how the photoactivity of oxynitrides can be enhanced with respect to their synthesis, including bulk and surface engineering such as doping (or substitution), controlling their morphology, and crystal facet engineering. Finally, we discuss the existing challenges to realizing efficient artificial photosynthesis using these materials. Perovskite and layered perovskite oxynitrides are regarded as promising visible-light-responsive semiconductors for efficient artificial photosynthesis to produce renewable value-added energy resources, including H2, formic acid, and ammonia.