Synergistic photocatalytic of CO2-to-CO conversion by 2D/1D Ti3C2Tx/p-BN heterojunction with interfacial chemical bonding

Herein, a series of novel Ti 3 C 2 T x /p-BN heterojunctions with excellent photocatalytic activity have been prepared by combining one-dimensional (1D) porous BN fibers (p-BN) with high aspect ratio and two-dimensional (2D) ultrathin Ti 3 C 2 T x MXenes for photocatalytic conversion of CO 2 -to-CO. Our results show that the optimized photocatalyst can photo-reduce CO 2 to generate CO under UV light with CO yield of 22.53 μmol g −1 h −1 , which is 4.3 and 20.1 times of p-BN (5.23 μmol g −1 h −1 ) and Ti 3 C 2 T x (1.23 μmol g −1 h −1 ), respectively. We demonstrate that the Ti 3 C 2 T x /p-BN heterojunction can combine the efficient CO 2 adsorption of porous p-BN and excellent electronic conductivity of Ti 3 C 2 T x . Moreover, the interfacial Ti-O-B bonds lead to strong interaction between p-BN and Ti 3 C 2 T x , resulting in the formation of Schottky heterojunction. The synergistic effect not only enables the adsorption of CO 2 by Ti 3 C 2 T x /p-BN heterojunction higher than p-BN, but also accelerates the transfer and separation of photogenerated carriers in p-BN, which finally exhibits promoted CO 2 photocatalytic activity. The present work pioneer the application of Ti 3 C 2 T x /p-BN heterojunction in photocatalytic CO 2 reduction and further guides the design of noble-metal-free photocatalysts.