2D/2D Heterostructured Photocatalysts: An Emerging Platform for Artificial Photosynthesis

2D/2D heterostructures have recently garnered substantial research attention due to their advantageous noble properties such as tunable band structures, high interfacial contact areas, and abundant active sites, which remarkably enhance photocatalytic activity. These intriguing properties render 2D/2D nanostructures highly auspicious in a multitude of photocatalytic energy applications, including water splitting for H 2 oxygen (O 2 ) evolution, reduction of CO 2 , and N 2 fixation. As such, this leads to the development of clean energy technology by 2D/2D catalysts and solar energy as the inexhaustible energy resource. Herein, the fundamental principles of 2D/2D hybrid heterostructures and diverse types of interfaces with different material families are systematically discussed. Furthermore, photocatalytic energy applications using 2D/2D heterointerfaces over the recent years are highlighted. Insights into the interplay of 2D/2D heterojunction interfaces and the associated physicochemical properties (e.g., charge carrier dynamics) toward the photocatalytic enhancement are put forward. Last but not least, the challenges and prospects in engineering 2D/2D heterostructure photocatalysts for affordable and clean energy advancements are reviewed, which serve as a guiding star not only in photocatalysis, but also in other applications in the energy realm such as fuel cells, batteries, supercapacitors, and photovoltaics.