Efficient Photoelectrochemical Route for the Ambient Reduction of N₂ to NH₃ Based on Nanojunctions Assembled from MoS₂ Nanosheets and TiO₂

Efficient nitrogen fixation under ambient conditions is an exigent task in both basic research and industrial applications. Recently, reduction of N₂ to NH₃ based on photocatalysis and/or electrocatalysis offers a possible route to the typical Haber–Bosch process. However, achieving a high yield of N₂ reduction reaction (NRR) is still a challenging goal because of the limitations of efficient catalysts. Herein, we propose a photoelectrochemical NRR route based on the rational design of MoS₂@TiO₂ semiconductor nanojunction catalysts through a facile hydrothermal synthetic method. The developed MoS₂@TiO₂ photocathode attains a high NH₃ yield rate (1.42 × 10^–6 mol h^–1 cm^–2) and a superhigh faradaic efficiency (65.52%), which is the highest record to the best of our knowledge. Moreover, MoS₂@TiO₂ exhibits high stability over 10 consecutive reaction cycles. Therefore, this work demonstrates an effective NRR photoelectrocatalyst and results in a breakthrough in the low faradaic efficiency because of the interfacial electronic coupling and synergistic effects between the MoS₂ and TiO₂ components.