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

The conversion of low-concentration nitrate into value-added ammonia (NH₃) 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 SnS₂/TiC interface, the strong adsorption and highly active catalytic sites are generated to activate ^*H and ^*NO₃⁻, 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 NO₃⁻ reduction reaction (NO₃⁻RR) catalysis. Therefore, the optimized SnS₂/TiC heterostructures display a high NH₃ 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 NH₃ 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.