2D-MXenes to tackle wastewater: From purification to SERS-based sensing

Due to their controlled and manipulative optical, electronic, mechanical, molecular, and thermal properties, 2D MXenes-based sensors are emerging as high-performance analytical tools for detecting various types of organic or pharmaceutical contaminants, including dyes such as Methylene blue (MB), methyl orange (MO) and metallic ions such as lead (Pb2+), chromium (Cr2+), copper (Cu2+), mercury (Hg2+) and many more from the waste or discharged water. The photocatalytic capabilities of 2D MXene are considered to be a practical approach to the degradation of water pollutants due to its durability, low power consumption, and environment-friendly nature. This process requires natural solar irradiation and photocatalyst such as MXene or their composites for water purification. This review addresses MXenes as an effective and efficient absorbent and catalytic material for wastewater treatment. Various synthesis schemes of MXenes and Surface Enhanced Raman Spectroscopy (SERS) substrates for photocatalytic water purification and elimination of organic & inorganic contaminations are highlighted. MXene-based SERS detection systems & stability of MXenes are critically discussed. The future perspective of MXenes-based photocatalytic and SERS-based sensing performances, limitations, and challenges for a sustainable environment are also presented, which can provide a pathway to understanding the full potential of MXenes.