Engrossing structural developments of double perovskites for viable energy applications

Investigation for novel functional catalysts illustrates an essential direction in advancing and researching renewable energy. On account of their specific compositional and structural tunability and remarkable stability, double perovskites have been extensively examined as a category of versatile compounds for applications in photocatalysis and electrocatalysis, highlighting them as a promising candidate for catalytic performance and stability. In this review article, we have elaborated on the tunability of double perovskites in terms of their compositions and structures, which proved to be tremendous features for double perovskites in diverse applications. Furthermore, the fabrication methods and the performance optimization comprising band gap tuning of double perovskites have been discussed. The current status of double perovskites for photocatalytic and electrocatalytic H 2 production and CO 2 reduction, with recent reports, has also been reviewed. Lastly, the challenges and future outlook are put forward. • Structural classification, fabrication technologies and sustainable energy applications. • Conventional and non-conventional synthetic methodologies. • Optimization of catalyst performance via band gap engineering. • Photocatalytic/electrocatalytic CO 2 reduction and H 2 evolution.