Mn-Doped Bi2O3 Nanosheets from a Deep Eutectic Solvent toward Enhanced Electrocatalytic N2 Reduction

Abstract

The electrochemical nitrogen reduction reaction (NRR) is a promising green substitute to the resource-consuming Haber–Bosch process. However, it is still far from the industrialized application due to the deficiency of superior catalysts to activate the inert N2 molecules. Bi-based materials, especially Bi2O3, have been utilized for the NRR due to intrinsic suppression of the hydrogen evolution reaction (HER), but the inferior conductivity and low faradaic efficiency (FE) hamper its popularity in the NRR. Herein, for the first time, we designed Mn-doped Bi2O3 nanosheets from a deep eutectic solvent (DES) for the electrochemical NRR. The Mn-doped Bi2O3 nanosheets demonstrated a high NH3 yield rate of 23.54 μg h–1 mgcat.–1 with an enhanced FE of 21.63% in a Na2SO4 electrolyte at −0.1 V versus the reversible hydrogen electrode, superior to previous Bi2O3 catalysts. The result indicated that introducing Mn into Bi2O3 elevates the FE for the NRR by suppressing the adverse HER. Our work offers an instructive Mn doping strategy via the DES approach for ameliorating the NRR performance of Bi2O3, holding great promise for the design of advanced catalysts toward the NRR.