Outstanding photocatalytic nitrogen fixation performance of TiO₂ QDs modified by Bi₂O₃/NaBiS₂ nanostructures upon simulated sunlight

Nowadays, a promising material for NH₃ production under mild and safe conditions using heterogeneous photocatalysts is very important. In this regard, Bi₂O₃ and NaBiS₂ nanoparticles were combined with TiO₂ quantum dots (QDs) through a facile hydrothermal process. The TiO₂ QDs/Bi₂O₃/NaBiS₂ nanocomposites displayed excellent performance in the photofixation of nitrogen upon simulated sunlight. The NH₃ generation rate constant over the optimum nanocomposite was 10.2 and 3.3-folds higher than TiO₂ (P25) and TiO₂ QDs photocatalysts, respectively. The spectroscopic and electrochemical studies affirmed more effective segregation and transfer of photo-induced charge carriers within ternary nanocomposite, due to the developing tandem n-n-p heterojunctions, which led to more lifetime of charges. Moreover, the impacts of solvent, pH, electron scavenger, and lake of nitrogen molecules on the NH₃ generation were investigated. Finally, it was concluded that the TiO₂ QDs/Bi₂O₃/NaBiS₂ nanocomposite, with appealing features of more activity, high stability, and a facile one-pot synthesis method, is a promising photocatalyst in nitrogen fixation technology.