Electric Field Reconstruction Enables Piezoelectric Ammonia Synthesis From Low‐Concentration Nitrates

ABSTRACT The conversion of low‐concentration nitrate into value‐added ammonia (NH ₃ ) is hindered by sluggish kinetics and inefficient electron utilization in conventional photo‐ and electrocatalytic systems. Herein, this work proposes a unique electric field reconstruction strategy to achieve efficient piezoelectric reduction of nitrate to ammonia. Through electric field reconstruction at the SnS ₂ /TiC interface, the strong adsorption and highly active catalytic sites are generated to activate ^* H and ^* NO ₃ ⁻ , thereby enhancing deoxygenation and hydrogenation processes. In addition, piezoelectric‐driven field reconstruction not only accelerates charge carrier migration, but also modulates the electronic energy bands, further facilitating the NO ₃ ⁻ reduction reaction (NO ₃ ⁻ RR) catalysis. Therefore, the optimized SnS ₂ /TiC heterostructures display a high NH ₃ synthesis rate of 10.26 mmol g ⁻¹ h ⁻¹ and a high electron utilization of 98% at low concentrations, surpassing most previously reported photocatalytic NH ₃ production rates and electrocatalytic electron utilization. Moreover, the residual nitrate concentration was reduced below the World Health Organization drinking water standard. Electric field reconstruction at the heterostructural interface provides a tunable and efficient route for green ammonia production via piezoelectric catalysis.