Multiphasic 1T@2H MoSe2 as a highly efficient catalyst for the N2 reduction to NH3

[Display omitted] •Multiphasic 1T@2H MoSe2 is demonstrated as a highly efficient catalyst for nitrogen fixation.•The 1T@2H-MoSe2 exhibits outstanding selectivity and activity under ambient conditions.•The presence of 1T phase improves the electron transfer ability with smaller resistance.•The 1T phase enhances the mass transportation ability by affording more exposed active sites. The NH3 is generally synthesized by the traditional Haber–Bosch method, which is energy-consuming and releases a lot of CO2. Electrocatalytic fixation of N2 is highlighted as a carbon-free route to generate NH3 by the nitrogen reduction reaction (NRR), but strongly demands highly efficient and durable electrocatalysts. Herein, we propose the multiphasic 1T@2H-MoSe2 as a highly active NRR catalyst for the first time, which exhibits excellent activity for the NRR with a NH3 yield of 19.91 ± 0.89 μg h−1 mgcat.−1 and a FE of 2.82% ± 0.1% at −0.6 V in 0.1 M Na2SO4. Moreover, a good durability is also demonstrated.