TiO₂/Fe Heterostructure Enables High-Efficiency Electrochemical Ammonia Synthesis from Nitrate

Abstract

The rational design of heterostructures offers a powerful strategy to enhance the performance towards nitrate (NO3-) reduction to ammonia (NRA). In this work, we successfully constructed a TiO2/Fe heterostructure by anchoring Fe nanoparticles onto TiO2 nanorod arrays, which achieves an impressive Faradaic efficiency of 93.3% at -0.7 V vs. RHE and a high NH3 yield rate of 11.96 mg h⁻1 cm⁻² at -0.8 V vs. RHE. Both experimental investigations and theoretical calculations reveal that the TiO2/Fe heterostructure effectively enhances NO3- adsorption, facilitates the dissociation of H2O for generating more active hydrogen, and lowers the energy barrier. This work provides valuable insights into the design of advanced heterostructure catalysts for NRA.