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• We reported CeO x -S/ZnIn2S4 catalysts with size of CeO x -S clusters less than 2 nm. • The CeO x -S/ZnIn2S4 hybrid catalysts hold rich surface defects. • CeO x -S/ZnIn 2 S 4 had higher activity in photocatalytic CO 2 reduction than ZnIn 2 S 4. • Oxygen vacancies on CeO x -S/ZnIn 2 S 4 can trap electrons and then transfer to CO 2. • The Ce–S can lower activation energy barrier during CO 2 reduction. Engineering the electronic properties of heterogeneous catalysts is an important strategy to enhance their activity towards CO 2 reduction. Herein, we prepared partially sulfurized cerium oxide (CeO x -S) nanoclusters with the size less than 2 nm on the surface of ZnIn 2 S 4 layers. Surface electronic properties of CeO x -S nanoclusters are facilely modulated by cerium coordination to sulfur, inducing the emergence of abundant Ce3+ and oxygen vacancies. For the photoreduction of CO 2 , CeO x -S/ZnIn 2 S 4 hybrid catalysts exhibited a CO productivity of 1.8 mmol g−1 with a rate of 0.18 mmol g−1 h−1, which was twice as higher as that of ZnIn 2 S 4 catalyst using triethylamine as a sacrificial electron donor. Further mechanistic studies reveal that the photogenerated electrons are trapped by oxygen vacancies on CeO x -S/ZnIn 2 S 4 catalysts and subsequently transfer to CO 2 , benefiting the activation of CO 2. Moreover, the extremely high selectivity of CO is derived from the weak adsorption of CO on the surface of CeO x -S/ZnIn 2 S 4 catalysts. [ABSTRACT FROM AUTHOR]

• Ti 3 C 2 T x /TiO 2 -400 toward NIR light-driven N 2 photofixation was successfully developed by combining Ti 3 C 2 T x MXene with TiO 2. • The NH 3 production rate of Ti 3 C 2 T x /TiO 2 -400 reached 422 μmol g cat. –1 h–1 under full-spectrum in water without any sacrificial agents. • Superior activity was achieved for Ti 3 C 2 T x /TiO 2 -400 with the NH 3 production rate of 82 μmol g cat. –1 h–1 by applying 740-nm monochromatic light. • Plasmonic Ti 3 C 2 T x Mxene phase in Ti 3 C 2 T x /TiO 2 -400 enabled the harvesting of NIR light to generate hot electrons. • Oxygen vacancies in TiO 2 phase of Ti 3 C 2 T x /TiO 2 -400 served as the active centers to efficiently adsorb and activate N 2 molecules. Utilization of infrared (IR)/near-infrared (NIR) light paves an opportunity to improve the efficiency of N 2 photofixation under full-spectrum irradiation, but remains as a grand challenge. Herein, a highly active photocatalyst toward NIR light-driven N 2 photofixation was successfully developed by construction of plasmonic Ti 3 C 2 T x MXene and TiO 2 hybrid structures (Ti 3 C 2 T x /TiO 2 -400). Impressively, Ti 3 C 2 T x /TiO 2 -400 exhibited remarkable activity in N 2 photofixation under full-spectrum irradiation of Xenon lamp, attaining an NH 3 production rate of 422 μmol g cat. –1 h–1 without any sacrificial agents. More importantly, superior activity under NIR light was even achieved for Ti 3 C 2 T x /TiO 2 -400 with the NH 3 production rate up to 82 μmol g cat. –1 h–1 by applying 740-nm monochromatic light. Further mechanistic studies revealed that plasmonic Ti 3 C 2 T x Mxene phase in Ti 3 C 2 T x /TiO 2 -400 enabled the harvesting of NIR light. Moreover, oxygen vacancies in TiO 2 phase of Ti 3 C 2 T x /TiO 2 -400 served as the active centers to efficiently adsorb and activate N 2. [ABSTRACT FROM AUTHOR]