“FeV-cofactor”-inspired bionic Fe-doped BiVO4 photocatalyst decorated with few-layer 2D black phosphorus for efficient nitrogen reduction

Abstract

Drawing inspiration from the biological nitrogenase mechanism, bionic photocatalytic nitrogen fixation technology plays a significant role in activating nitrogen molecules and promoting the nitrogen reduction reaction. However, developing effective semiconductor photocatalysts remains a considerable challenge in the field of bionic nitrogen fixation. Herein, a novel bionic “FeV-cofactor” system for performing photocatalytic nitrogen reduction was proposed for the first time based on an Fe-doped BiVO₄ photocatalyst decorated with few-layer 2D black phosphorus (BP). As expected, Fe doping and BP decoration significantly improved the NH₃ yield of BiVO₄. With an NH₃ yield of 337.9 μmol g⁻¹ h⁻¹ (6.83 times that of BiVO₄), FeBiVO₄-0.05BP ranks among the top-performing nitrogen-fixing materials in oxide-based photocatalysts. DFT calculations show that N₂ molecules can be adsorbed and activated by Fe doping, thus forming the in-built bionic “FeV-cofactor”. The experimental results further confirm that introducing a bionic “FeV-cofactor” system enhances the electron transfer between redox couples (V⁵⁺/V⁴⁺ & Fe³⁺/Fe²⁺) and N₂, thus improving the carrier separation efficiency. Oxygen vacancies coupled with V⁴⁺ ions also contribute to increasing light absorption. The 2D BP decoration plays a crucial role in the whole process of nitrogen reduction due to its exceptional electron transfer ability while increasing the active sites of the reaction.