Energy-autonomous electrocatalysis for landfill leachate remediation using a TENG-EMG hybrid generator

Under the leaching effect of rainwater, landfill sites will produce leachate containing high concentrations of harmful pollutants such as ammonia nitrogen (NH 4 + -N), which requires effective purification before discharge. Although electrochemical oxidation had been widely studied, its high energy consumption limited its application. For this purpose, this study developed a self-powered hybrid system that coupled Ti/SnO 2 -Sb 2 O 3 anode and a stainless-steel cathode with the triboelectric-electromagnetic generator (TENG-EMG), which achieved efficient electrocatalytic degradation of NH 4 + -N in landfill leachate without relying on external power sources. Through parameter optimization, the system achieved the optimal degradation rate constant of 0.289 min −1 under the conditions of a rotor speed of 90 r/min, NH 4 + -N concentration of 10 mg/L, pH 7, electrode spacing of 0.9 cm, and 0.1 M NaCl electrolyte. Mechanism studies demonstrated that the coupled system can effectively promote the generation of singlet oxygen (· 1 O 2 ), hydroxyl radicals (·OH), and active chlorine radicals (·Cl/·ClO), thereby driving the degradation of NH 4 + -N. This synergistic strategy significantly enhances the efficiency of environmental energy harvesting and electrocatalysis, providing an innovative solution for self-powered treatment of landfill leachate.