Constructing Active Sites on Self-Supporting Ti3C2Tx (T = OH) Nanosheets for Enhanced Photocatalytic CO2 Reduction into Alcohols

Ti3C2Tx (T = OH) was first prepared from Ti3AlC2 by HF etching and applied into a photocatalytic CO2 reduction. Then, the Ti3C2Tx nanosheets present interbedded a self-supporting structure and extended interlayer spacing. Meanwhile, the Ti3C2Tx nanosheets are decorated with abundant oxygen-containing functional groups in the process of etching, which not only serve as active sites but also show efficient charge migration and separation. Among Ti3C2Tx materials prepared by etching for different times, Ti3C2Tx-36 (Etching time: 36 h) showed the best performance for photoreduction of CO2 into alcohols (methanol and ethanol), giving total yield of 61 μmol g catal.−1, which is 2.8 times than that of Ti3AlC2. Moreover, excellent cycling stability for CO2 reduction is beneficial from the stable morphology and crystalline structure. This work provided novel sights into constructing surface active sites controllably.