Ag nanoparticles modified hollow tubular In2O3 for enhanced photocatalytic nitrogen reduction to ammonia

The photocatalytic nitrogen reduction reaction provides an alternative process for nitrogen cycling and ammonia (NH3) production under mild conditions. Herein, we have synthesized Ag-loaded In2O3 (Ag@In2O3-X) by solvothermal and photoreduction methods. The introduction of Ag significantly alters the band structure of In2O3, resulting in a slight reduction in the band gap and a more negative conduction band position, thereby facilitating the generation of reductive electrons in In2O3. Moreover, the synergistic interaction between loaded Ag nanoparticles and In2O3 forms a Schottky barrier, which widens the light absorption range and promotes charge separation. Under simulated sunlight, the photocatalytic nitrogen fixation performance of Ag@In2O3-5 reaches 35.56 μmol h−1 gcat−1, which is higher than other composites and 3.58 times that of pure In2O3. At the same time, the catalyst has good structural stability and cycle life. Density functional theory (DFT) calculations demonstrate that Ag exhibits a stronger interaction with N2 and lowers the potential barrier of the N2 hydrogenation reaction. The synergistic effect between precious metals and semiconductors offers novel insights and presents challenges for the photocatalytic N2 fixation process. This work provides new insights and challenges for designing and synthesizing nanomaterials for photocatalytic nitrogen fixation.