Pyrochlore oxides as visible light-responsive photocatalysts

Heterogeneous photocatalysis has been considered as one of the most attractive alternative routes to transform naturally abundant, clean, and sustainable solar energy into chemical energy. With a view to efficient solar-energy utilisation, the development of new materials, which are sensitive to visible light, is an important direction in the theory and practice of heterogeneous photocatalysis. In recent years, many efforts have been made in the context of the development of pyrochlore oxides as visible light-responsive photocatalysts for dye degradation, water splitting, and CO2 reduction. The interest to pyrochlores is attributed with their compositional flexibility to manipulate electron/hole mobility by introducing a wide range of elements into the structure. The present Perspective reports progress over the last 5 years in the use of pyrochlore-like oxides as promising photocatalysts for various applications. A special focus of this Perspective is on the strategies which allow to enhance the photocatalytic activity of pyrochlores, namely optimisation of preparation method, band gap engineering, incorporation of plasmonic metals, and creation of heterojunctions.