Boosting electrocatalytic ammonia synthesis from nitrate by asymmetric chemical potential activated interfacial electric fields.

ABSTRACT

The electrocatalytic nitrate reduction reaction (NO3- RR) has immense potential to alleviate the problem of groundwater pollution and may also become a key route for the environmentally benign production of ammonia (NH3) products. Here, the unique effects of interfacial electric fields arising from asymmetric chemical potentials and local defects were integrated into the binary Bi2S3-Bi2O3 sublattices for enhancing electrocatalytic nitrate reduction reactions. The obtained binary system showed a superior Faraday efficiency (FE) for ammonia production of 94 % and an NH3 yield rate of 89.83 mg gcat-1h-1 at -0.4 V vs. RHE. Systematic experimental and computational results confirmed that the concerted interplay between interfacial electric fields and local defects not only promoted the accumulation and adsorption of NO3-, but also contributed to the destabilization of *NO and the subsequent deoxygenation hydrogenation reaction. This work will stimulate future designs of heterostructured catalysts for efficient electrocatalytic nitrate reduction reactions.