Self-powered electrocatalytic ammonia synthesis directly from air as driven by dual triboelectric nanogenerators

Abstract

Electrocatalytic reduction at room temperature and atmospheric pressure is a promising low-power-consumption and eco-friendly pathway for replacing the traditional ammonia synthesis method, which is one of the largest chemical processes in terms of energy consumption and greenhouse gas emissions. In this work, we utilize triboelectric nanogenerators (TENGs) to construct an electrocatalytic ammonia synthesis system with air as the nitrogen source, which is self-powered, eco-friendly, low-cost, scalable and allows facile fabrication. The nitrogen fixation and electrocatalytic reduction can proceed simultaneously by introducing a high-output dual-TENG configuration. A needle-plate structure was utilized to achieve air discharge and thus obtain NO_X for further aqueous electrolyte formation. In addition, an electrochemical cell with TiO₂ as the catalyst was used to synthesize ammonia. Driven by the simulated waste gas at a flow rate of 3.5 m³ min⁻¹, the ammonia yield per hour of the self-powered electrocatalytic system reached 2.4 μg h⁻¹.