Synthesis and environmental applications of graphene oxide/layered double hydroxides and graphene oxide/MXenes: A critical review

The diverse characteristics of two-dimensional (2D) materials have gained considerable research attention because of their applicability in the development of sustainable environments. Researchers have focused on the development of advanced methods for preparing multifunctional 2D/2D composite materials such as graphene oxide-based layered double hydroxides (GO/LDHs) and MXenes (GO/MXenes) through various pathways with exceptional characteristics that can help new technologies to address the ongoing environmental issues. This critical review highlights the recent advancements in the synthesis and environmental applications including adsorption of metal ions, dyes, radioactive ions/nuclides, oil and organic solvents/compounds, and other pollutants; photocatalysis and water splitting; electrocatalysis; and antibacterial/antimicrobial activities of GO/ LDHs and GO/MXenes in detail. We have also depicted the materials' structure-adsorption property-performance relationship of those 2D/2D materials. Both composites afford excellent environmental applications because of their superb integration of exfoliation, the presence of active functional groups, interconnected systematic structural characteristics, and topological conversion properties. There are some crucial challenges and future opportunities including the development of sustainable budget-friendly methods with controlled composition and morphology, multipollutant remediation, separation and reusability along with valuation, optimization and database, unification between technology and upscaling process, and funding from sponsors, which are discussed in this critical review followed by the concluding remarks.