Synthetic Methodologies and Energy Storage/Conversion Applications of Porous Carbon Nanosheets: A Systematic Review

Owing to their unique morphologies, properties, and promising applications, two-dimensional (2D) porous carbon materials have attracted tremendous research interest in the past decade. These materials not only combine the advantages of both 2D and porous structures but also possess some excellent features, including nanoscale thickness, high surface area, and enhanced electronics, heat, and mass transport properties bestowing them with high potential for applications in energy storage, catalysis, and adsorption. 2D Porous carbon nanosheets (2D PCNS) have been extensively investigated since the explosive research on graphene. The key factor for the target application of these materials is their porous morphologies which are greatly affected by various synthetic procedures. This review focuses on the recent progress in synthetic methodologies for 2D PCNS, in which the main porosity controlling factors for each method are highlighted. Applications of such materials are discussed in detail in energy storage and conversion devices, including supercapacitors, lithium, sodium, potassium, and zinc-ion batteries, lithium–sulfur batteries, and heterogeneous catalysis. Finally, the challenges and prospects of the further development of 2D PCNS are discussed.