Pyridine functionalized silver nanosheets for nitrate electroreduction

Abstract

The nitrate electroreduction reaction (NO₃RR) serves as an environmentally friendly method for ammonia (NH₃) synthesis and effectively mitigates nitrate pollution in natural water bodies. The chemical functionalization of noble metal nanostructures can effectively enhance their activity and selectivity in electrocatalytic reactions. In this study, we successfully synthesized pyridine (Py) functionalized silver (Ag) nanosheets (Py–Ag NSs) as an electrocatalyst for NO₃RR. Density functional theory calculation results revealed that the adsorbed pyridine modulated the electronic structure of Ag atoms, thereby facilitating the adsorption of nitrate ions and the following reduction steps. Consequently, Py–Ag NSs revealed significantly improved activity for NO₃RR compared to pure Ag catalysts. Notably, at a potential of −0.53 V, Py–Ag NSs exhibited a faradaic efficiency and production rate of NH₃ reaching 96.6% and 72.664 mg h⁻¹ mg_cat⁻¹, respectively. This work provides valuable insights into the modulation of electronic structures using a chemical functionalization strategy, thus guiding the rational design of noble metal-based electrocatalysts.