Construction of BiOBr/Hydrophobic Carbon Cloth Heterojunction with Internal Electric Field for Enhanced Photocatalytic Nitrogen Fixation

Enhancing the separation efficiency of photogenerated charge carriers and suppressing the competition of the hydrogen evolution reaction (HER) are potential methods to improve the activity of photocatalytic nitrogen fixation. In this study, a BiOBr/hydrophobic carbon cloth (HCC) heterojunction with an internal electric field (IEF) has been successfully fabricated through a one-step solvent method. The IEF facilitates the migration of photogenerated electrons from BiOBr to the HCC. Concurrently, the HCC provides an N₂-rich environment, thereby suppressing the competitive HER. Theoretical calculations reveal that N₂ adsorbs on the Bi atom surface, with HCC acting as an electron transfer medium. Photogenerated electrons are transferred from HCC to the distal N atom, enhancing its activation and reducing the energy barrier of the rate-determining step. The nitrogen fixation yield of BiOBr/HCC is 202.2 µmol g^-1 h^-1. The ammonia produced by BiOBr/HCC has been successfully applied in the hydroponic experiment of pennywort, which confirms its non-toxicity and growth-promoting effects. The synthesis of BiOBr/HCC heterojunctions with superior nitrogen fixation capabilities has opened new avenues for the application of BiOBr-based catalysts in the field of nitrogen fixation, potentially leading to widespread use in agricultural production in the future.