<p>Compared to traditional energy-intensive ammonia (NH₃) production methods, photocatalytic nitrogen (N₂) reduction offers significant energy savings. However, the complex kinetics and high reaction barriers have hindered its development. In this study, a novel Bi₂₄O₃₁Br₁₀/polyaniline (Bi₂₄O₃₁Br₁₀/PANI) composite photocatalyst was synthesized using a simple solvothermal and chemical oxidation polymerization method. Aniline was oxidized and deposited onto the surface of Bi₂₄O₃₁Br₁₀ nanosheets. The Bi₂₄O₃₁Br₁₀/PANI composite demonstrated better visible-light absorption, and more efficient transfer of photoexcited carriers than pure Bi₂₄O₃₁Br₁₀, resulting in superior photocatalytic N₂ fixation performance. The optimized Bi₂₄O₃₁Br₁₀/PANI composite attained an NH₃ production yield of 245.26 µmol g⁻¹&#xa0;, approximately 7.0 times higher than pure Bi₂₄O₃₁Br₁₀. This study provides a new design of inorganic-polymer hybrid photocatalysts for efficient photocatalytic nitrogen fixation.</p> Graphical abstract <p></p>