Ultrathin 2D Ti₃C₂ MXene Co-catalyst anchored on porous g-C₃N₄ for enhanced photocatalytic CO₂ reduction under visible-light irradiation

Constructing an efficient photocatalyst is critical for photocatalytic carbon dioxide (CO2) into valuable fuel. Herein, a high-efficiency catalyst was synthesized by a simple one-step electrostatic self-assembly method, in which Ti3C2 (TC) was anchored on porous g-C3N4 (PCN) with rich -NHx via NHx-Ti bond. Such a chemical interaction made the optimized TC/PCN-2 with 2 wt% loading of Ti3C2 possess highest CH4 production (0.99 mu mol.h(-1).g(catalyst)(-1)) under visible light (>420 nm), which was 14 times higher than that of pure PCN (0.07 mu mol.h(-1).g(catalyst)(-1)) at the same condition. More importantly, the TC/PCN-2 photocatalyst still maintained satisfied activity after four cycles. Besides the formation of NHx-Ti chemical bonding and superior conductivity of Ti3C2 as a co-catalyst, which facilitated interfacial charges separation and migration, the exceptional performance could also attribute to the enhanced CO2 adsorption/activation and improved light-harvesting capability. This work provided a potential application in energy conversion with MXene as an efficient co-catalyst. (c) 2020 Elsevier Inc. All rights reserved.