Opening the window to the solar-driven world of MXenes: Mechanisms, synergistic strategies, and emerging applications for sustainable environmental purification

Securing safe water supplies under increasingly complex contaminant burdens while curbing energy and chemical inputs is a defining challenge for environmental science and technology. Solar-driven photothermal purification concentrates heat at solid–liquid interfaces, accelerating mass transfer and reaction kinetics for intensified water treatment. MXenes (Mn+1XnTx), a rapidly expanding family of two-dimensional transition-metal carbides and nitrides, combine broadband absorption, metallic conductivity, and tailorable surface terminations, making them attractive photothermal platforms. This review synthesizes and critically evaluates MXene-enabled photothermal technologies, linking electronic structure, localized surface plasmon resonance, and interfacial chemistry to photon-to-heat conversion, heat confinement, and coupling with interfacial redox pathways. We consolidate design strategies, including metallic integration, heterojunction construction, polymers combination, and oxygen vacancy engineering, and highlight how these levers broaden solar harvesting while mitigating oxidation and restacking in realistic water matrices. The multifunctional roles of MXene-based systems in pollutant degradation, solar-assisted disinfection, oil-water separation, and interfacial solar evaporation/desalination are assessed with attention to performance metrics, robustness, and regeneration. Finally, we identify priorities for translation, including standardized durability testing under salinity/oxidants and irradiation, scalable and greener synthesis/assembly, and rigorous environmental and biological safety and life-cycle evaluation to enable durable, eco-safe remediation.