Strain of BN Induced by Graphene Oxide to Enhance Electrocatalytic Nitrogen Reduction

Ammonia (NH₃) is primarily produced through the traditional Haber–Bosch (H–B) technology which features high energy consumption and high pollution. As a sustainable alternative, electrocatalytic nitrogen reduction (eNRR) has attracted significant attention for its potential to replace the H–B process under ambient conditions. The key challenge lies in developing efficient catalysts to achieve high Faradaic efficiency (FE) for eNRR at normal temperature and pressure. Here, a metal-free composite catalyst composed of hexagonal boron nitride nanosheets (h-BNNs) and graphene oxide (GO) (h-BNNs/GO) was designed for ambient eNRR. A weak strain effect was induced between the layered structure of GO and h-BNNs, which contributed to an enhanced NH₃ yield rate of 25.0 μg h⁻¹ mg_cat.⁻¹) at −0.7 V versus reversible hydrogen electrode (RHE) in neutral media. Notably, the composite catalyst exhibited a remarkable 52.6% FE, a significant improvement over pure h-BNNs (4.7% FE). Furthermore, the morphology of the carbon support (e.g., GO vs. CNTs) was found to influence the strain effect, directly impacting the eNRR performance. This work provides valuable insights for strain-engineered catalyst design, advancing the development of sustainable nitrogen fixation technologies.

Graphical Abstract