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

Herein, a series of novel Ti3C2Tx/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 twodimensional (2D) ultrathin Ti3C2Tx MXenes for photocatalytic conversion of CO2-to-CO. Our results show that the optimized photocatalyst can photo-reduce CO2 to generate CO under UV light with CO yield of 22.53 mu mol g(-1) h(-1), which is 4.3 and 20.1 times of p-BN (5.23 mu mol g(-1) h(-1)) and Ti3C2Tx (1.23 mu mol g(-1) h(-1)), respectively. We demonstrate that the Ti3C2Tx/p-BN heterojunction can combine the efficient CO2 adsorption of porous p-BN and excellent electronic conductivity of Ti3C2Tx. Moreover, the interfacial Ti-O-B bonds lead to strong interaction between p-BN and Ti3C2Tx, resulting in the formation of Schottky heterojunction. The synergistic effect not only enables the adsorption of CO2 by Ti3C2Tx/p-BN heterojunction higher than p-BN, but also accelerates the transfer and separation of photogenerated carriers in p-BN, which finally exhibits promoted CO2 photocatalytic activity. The present work pioneer the application of Ti3C2Tx/p-BN heterojunction in photocatalytic CO2 reduction and further guides the design of noble-metal-free photocatalysts. (C) 2022 Elsevier B.V. All rights reserved.