MXenes-based materials for CO2 capture and conversion: A comprehensive review

CO2 concentration in the atmosphere is rapidly increasing, causing serious environmental problems and threatening the sustainability of life on Earth. To combat CO2 emissions, several materials have been developed and applied in some studies. One class of emerging nanomaterials with a potential efficacy for CO2 capture and conversion is MXenes. However, comprehensive and up-to-date reviews, as the one devised herein, on the utilization of MXenes for CO2 capture and conversion are still greatly lacking in the published research. Accordingly, this work is devoted to reviewing the recent developments in MXenes applications for CO2 capture and conversion into valuable chemicals and fuels. To provide the reader with a comprehensive knowledge on the topic, MXenes synthesis, characterization, and structural modifications aiming to boost charge separation and visible light absorption and, thus, photocatalytic performance has been presented before delving into CO2 capture and conversion contents. Then, recent studies on CO2 capture, including Direct Air Capture, using MXene-based materials as adsorbents have been reviewed. Additionally, CO2 separation from gas mixtures using membranes (including mixed matrix membranes) fabricated from MXene-based materials has been thoroughly presented and discussed. More importantly, recent studies on the application of MXene-based materials for the photocatalytic and electrocatalytic conversion of CO2 into valuable chemicals and fuels have been extensively discussed; the involved mechanisms in these conversion processes have been detailed. This review concludes by highlighting the challenges, limitations, and obstacles still facing the deployment of MXenes-based materials for CO2 capture and conversion while suggesting future research directions to address them.