Efficient nitrogen fixation under ambient conditions is an exigent task in both basic research and industrial applications. Recently, reduction of N 2 to NH 3 based on photocatalysis and/or electrocatalysis offers a possible route to the typical Haber-Bosch process. However, achieving a high yield of N 2 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 MoS 2 @TiO 2 semiconductor nanojunction catalysts through a facile hydrothermal synthetic method. The developed MoS 2 @TiO 2 photocathode attains a high NH 3 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, MoS 2 @TiO 2 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 MoS 2 and TiO 2 components.