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

[Display omitted] •Ti3C2Tx/TiO2-400 toward NIR light-driven N2 photofixation was successfully developed by combining Ti3C2Tx MXene with TiO2.•The NH3 production rate of Ti3C2Tx/TiO2-400 reached 422 μmol gcat.–1 h–1 under full-spectrum in water without any sacrificial agents.•Superior activity was achieved for Ti3C2Tx/TiO2-400 with the NH3 production rate of 82 μmol gcat.–1 h–1 by applying 740-nm monochromatic light.•Plasmonic Ti3C2Tx Mxene phase in Ti3C2Tx/TiO2-400 enabled the harvesting of NIR light to generate hot electrons.•Oxygen vacancies in TiO2 phase of Ti3C2Tx/TiO2-400 served as the active centers to efficiently adsorb and activate N2 molecules. 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.