2D Transition Metal Carbides (MXenes) for Carbon Capture

Abstract

Global warming caused by burning of fossil fuels is indisputably one of mankind's greatest challenges in the 21st century. To reduce the ever-increasing CO₂ emissions released into the atmosphere, dry solid adsorbents with large surface-to-volume ratio such as carbonaceous materials, zeolites, and metal-organic frameworks have emerged as promising material candidates for capturing CO₂ . However, challenges remain because of limited CO₂ /N₂ selectivity and long-term stability. The effective adsorption of CO₂ gas (≈12 mol kg^-1 ) on individual sheets of 2D transition metal carbides (referred to as MXenes) is reported here. It is shown that exposure to N₂ gas results in no adsorption, consistent with first-principles calculations. The adsorption efficiency combined with the CO₂ /N₂ selectivity, together with a chemical and thermal stability, identifies the archetype Ti₃ C₂ MXene as a new material for carbon capture (CC) applications.