B-doped MoS2 for nitrate electroreduction to ammonia

Electrocatalytic nitrate-to-ammonia conversion (NO3RR) is a promising route to achieve both NH3 electrosynthesis and wastewater treatment. Herein, we report B-doped MoS2 nanosheet arrays as an efficient NO3RR catalyst, delivering an NH3-Faradaic efficiency of 92.3 % with the corresponding NH3 yield of 10.8 mg h-1 cm-2 at -0.7 V (RHE). Theoretical computations identify B-dopants as the pivotal active sites to enhance NO3- activation and optimize the free energies of reaction intermediates, leading to the expedited NO3RR activity. Meanwhile, the undesired hydrogen evolution can be well suppressed on B-MoS2 to render a high NO3RR selectivity.