Ultra-low-voltage ammonia production in overall chloride-rich wastewater electrolysis of HMF/nitrite enabled by a Ta-induced multi-heterostructured nanocluster catalyst with enhanced photothermal effect

Abstract

In this paper, we report a Ta-induced multi-heterostructured nanocluster catalyst grown on copper foam for efficient co-electrolysis in chloride-rich nitrite wastewater. The incorporation of Ta not only enhances the active area, charge transfer, and corrosion resistance but also introduces a pronounced photothermal effect. As a bifunctional catalyst, it drives both HMF oxidation and nitrite reduction at 100 mA cm⁻² with a record-low cell voltage of 1.22 V under a light–electric hybrid field. This system achieves a 904.65% increase in NH₃ yield and up to 48.98% energy saving compared to pure electric-field operation, surpassing most reported dual-functional nitrate/nitrite-based electrolyzers.