Design, synthesis and modification of 2D nanomaterials-based photocatalysts for pollutant degradation and photodegradation experiments from lab-scale to grand-scale

2D nanomaterials display unique properties for photocatalytic energy conversion and for the treatment of water and air pollution thanks to their characteristic atomic structure and physicochemical properties. A deeper understanding of the structure–property relationships of photocatalysts constructed with 2D nanomaterials is of great significance for the development of new-generation high-performance photocatalysts. In this review, detailed mechanisms of photocatalytic reaction processes and pollutant degradation by 2D nanomaterial-based photocatalysts are outlined. Subsequently, preparation strategies and various modification approaches including elemental doping, defect design, and heterostructure construction are presented, together with the principle of modulating the energy-band structure of electrode materials. Methods for the construction of heterojunctions with various configurations based on 2D nanomaterials are elucidated. Current experimental evaluations and approaches for pollutant removal are summarized, showing the use of different types of photoreactors, from lab-scale to grand-scale. Finally, the opportunities and challenges for 2D nanomaterial-based photocatalysts for pollutant degradation are discussed.