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

Abstract

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.