Enhanced artificial nitrogen fixation into ammonia via CNT-modified BiFeO3-TiO₂ heterojunction

Photocatalytic ammonia synthesis from nitrogen and water is a promising avenue for energy development due to its potential for sustainable production. In this study, the BiFeO₃-TiO₂-CNT nanocomposite, produced via a facile sol-gel and hydrothermal method (with and without CNTs), effectively converts N₂ into ammonia, a modern, sustainable and H-based fuel. The optimized composite, BFO-10 %TiO₂-CNT, exhibited a remarkable ammonia production rate of 150.8 μmol/g·h under ambient conditions, exceeding the performance of other ratios. CNT inclusion enhanced the photocatalytic performance. The superiority of BiFeO₃-TiO₂-CNT nanocomposite solar energy materials was explained in terms of CNT's ability to increase the photocatalyst surface area and effective interaction with N₂ molecules and the positive effect on photon absorption. The BiFeO₃–10 %TiO₂-CNT nanocomposite showed significantly better photocatalytic performance than other combinations. This optimized composite produced more NH₃ than BiFeO₃ or TiO₂ alone. A proposed charge transfer mechanism explains the enhanced N₂ fixation into ammonia solar fuel.