Redox regulation of photocatalytic nitrogen reduction reaction by gadolinium doping in two-dimensional bismuth molybdate nanosheets

Abstract

Photocatalytic nitrogen reduction can achieve sustainable NH3 synthesis at room temperature and pressure, which is a more sustainable technology than the classical Haber-Bosch process. Herein, based on the ability of Gd3+ ions to capture and release electrons, a novel Gd-doped 2D Bi2MoO6 nanosheet photocatalyst for nitrogen reduction with in-built Gd3+ redox center was designed and prepared. The results showed that Gd3+ doping can increase the number of reaction sites by increasing the specific surface area of 2D Bi2MoO6, and promote the separation and transfer of photogenerated carriers by forming in-built Gd3+ redox centers. The visible-light-driven nitrogen reduction performance of Gd-Bi2MoO6 was obviously improved, and the average yield of NH3 was 300.15 μmol g-1 h−1, which was about 5.8 times that of pure Bi2MoO6. Theoretical calculations showed that the Gd3+ redox centers can also control the formation of *NHNH to regulate the nitrogen reduction reaction, which greatly reduces the free energy of the whole nitrogen reduction reaction, thus effectively accelerating the conversion of N2 to NH3. The significance of this work is to prove that the lanthanide ion Gd3+ can be used to regulate the nitrogen reduction reaction of 2D catalyst and enhance the performance of nitrogen reduction reaction.