Recent progress on strategies for the preparation of 2D/2D MXene/g-C3N4 nanocomposites for photocatalytic energy and environmental applications

Recently, an enormous group of novel two-dimensional (2D) transition metal carbides, carbonitride and nitrides, known as MXenes, have attracted increasing interest owing to their elemental compositions and surface terminations. Accordingly, MXenes derived from the MAX phase, participating as a co-catalyst or supporting material with 2D g-C3N4 have been used in photocatalytic systems and are effective due to the creation of an interface and Schottky heterojunction, which accelerate the separation of charge carrier pairs for excellent photocatalytic activities. Thus, the combination of 2D/2D MXene/g-C3N4 can be a tremendous mode to overcome the limitations of individual semiconductors. Encouraged by these features, in this review, we present the latest synthetic strategies for the preparation of 2D/2D MXene/g-C3N4 nanocomposites and explore the role of MXenes as a support or co-catalyst material considering recent advances in their application including H-2 evolution, NO purification, H2O2 evolution, CO2 reduction, and pollutant degradation. In addition, the mechanism for charge separation in 2D/2D MXene/g-C3N4 nanocomposites for photocatalytic application is discussed and an outlook for their future perspectives is also outlined. This review also presents the promising research progress in the area of photocatalysis involving MXene/g-C3N4 materials together with innovative technologies for significant insight into these processes, which can be established in the near future to deal with energy- and environment-related challenges.