Alkanolamine intercalation assisted liquid phase exfoliation of titanium carbide MXene nanosheets for highly efficient photocatalytic CO2 reduction

Two-dimensional titanium carbide (Ti3C2Tx) MXene nanosheets have been widely concerned due to its abundant surface functional groups, high conductivity, excellent photoelectrochemical properties and thermal conductivity. Nevertheless, it is still a challenge for the mass production of high-quality Ti3C2Tx MXene nanosheets. Herein, the bulk Ti3C2Tx MXene powders were stripped into monolayer or few layer nanosheets in propylene carbonate through liquid-phase exfoliation strategy assisted via alkanolamine as intercalators. It is shown that the stripping yield is up to 59.3%, which is the recorded value for the delamination of Ti3C2Tx MXene nanosheets from bulk Ti3C2Tx MXene powder, and 62.2% of nanosheets are monolayer. The ability of hydrogen bond donor and molecular size of alkanolamine have important effects on the yield. Moreover, Ti3C2Tx MXene nanosheets have been employed as catalysts in the photocatalytic CO2 reduction. The yield of CO is 149.7 μmol g-1 h-1, which is about five times that of bulk Ti3C2Tx MXene powder. This work paves the way for the mass production of MXene nanosheets with high activity photocatalysis.