Ce-doped MoS2−x nanoflower arrays for electrocatalytic nitrate reduction to ammonia

Abstract

Electrocatalytic reduction of nitrate to ammonia (NO₃RR) represents a highly appealing route to achieve both value-added NH₃ synthesis and facile removal of waste nitrate. In this study, Ce-doped and S-vacancy-enriched MoS_2−x nanoflower arrays are reported as a highly efficient NO₃RR catalyst, exhibiting an NH₃-faradaic efficiency of 96.6% with a corresponding NH₃ yield rate of 7.3 mg h⁻¹ cm⁻². Theoretical calculations highlight the synergy of the S-vacancy and Ce-dopant to enhance the NO₃RR activity of Ce–MoS_2−x, in which the S-vacancy-induced unsaturated Mo serves as an active site to activate NO₃⁻, while the Ce-dopant jointly enhances NO₃⁻ activation and reduces the thermodynamic energy barrier for the rate-determining step of *NO → *NOH.