Near-infrared light-driven photofixation of nitrogen over Ti3C2Tx/TiO2 hybrid structures with superior activity and stability

Abstract Utilization of infrared (IR)/near-infrared (NIR) light paves an opportunity to improve the efficiency of N2 photofixation under full-spectrum irradiation, but remains as a grand challenge. Herein, a highly active photocatalyst toward NIR light-driven N2 photofixation was successfully developed by construction of plasmonic Ti3C2Tx MXene and TiO2 hybrid structures (Ti3C2Tx/TiO2-400). Impressively, Ti3C2Tx/TiO2-400 exhibited remarkable activity in N2 photofixation under full-spectrum irradiation of Xenon lamp, attaining an NH3 production rate of 422 μmol gcat.–1 h–1 without any sacrificial agents. More importantly, superior activity under NIR light was even achieved for Ti3C2Tx/TiO2-400 with the NH3 production rate up to 82 μmol gcat.–1 h–1 by applying 740-nm monochromatic light. Further mechanistic studies revealed that plasmonic Ti3C2Tx Mxene phase in Ti3C2Tx/TiO2-400 enabled the harvesting of NIR light. Moreover, oxygen vacancies in TiO2 phase of Ti3C2Tx/TiO2-400 served as the active centers to efficiently adsorb and activate N2.