Effective 1D/2D nanostructured S-scheme W18O49/g-C3N4 heterojunction photocatalyst fabrication for improved photocatalytic nitrogen fixation performance

The fundamental insights into the reaction mechanism, especially the electron transfer mechanism, are highly promising yet challenging for W 18 O 49 /g-C 3 N 4 heterojunction catalysts during photocatalytic nitrogen fixation. Herein, the 1D/2D nanostructured S-scheme heterojunctions were designed by in situ growth of 1D W 18 O 49 nanowires on 2D g-C 3 N 4 nanosheets through solvothermal method using methanol as solvent. In situ XPS analysis revealed that electrons in the conduction band of W 18 O 49 recombine with holes in the valence band of g-C 3 N 4 under the conduction effect of internal electric field, band bending, and Coulombic attraction in the W 18 O 49 /g-C 3 N 4 heterojunction. The photogenerated electrons are retained in g-C 3 N 4 , where the negative reduction potential of its conduction band enhances the activation of N 2 . As a result, the ammonia generation rate employing the optimal W 18 O 49 /g-C 3 N 4 heterojunction is 64.8 μmol g cat −1 h −1 , approximately double that of W 18 O 49 alone and 2.3 times higher than that of g-C 3 N 4 . The enhanced activity and facile methodology make the current material exceedingly appealing for implementation in photocatalytic nitrogen fixation for the synthesis of ammonia.