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.