Like-enzyme cascades of copper–cobalt oxides heterojunction boosts highly efficient nitrate electroreduction to ammonia for agriculture application

The electrochemical reduction of nitrate (NO₃⁻) presents a sustainable approach for mitigating NO₃⁻ contamination while generating value-added ammonia (NH₃). However, achieving high efficiency and selectivity under ambient conditions remains a significant challenge. Here, we develop an enzyme-like CuO-Co₃O₄ heterojunction catalyst that efficiently facilitates NO₃⁻ reduction to NH₃ under neutral conditions, mimicking enzymatic active sites to boost activity. The enzyme-like catalyst exhibits an exceptional NO₃⁻ conversion rate of 99.6 % and 100 % NH₃ selectivity, achieved through the optimization of interfacial electronic interactions. In-situ Raman spectroscopy and density functional theory analyses reveal that cascade reactions facilitated by the CuO-Co₃O₄ interface significantly enhance the rate-determining step and lower the energy barrier, thereby improving NO₃⁻ electroreduction efficiency. Furthermore, a continuous supply system suppling NH₄⁺-N demonstrates its potential to promote plant growth and fruit production, highlighting its practical applicability. This study offers targeted strategies for addressing NO₃⁻ contamination, synthesizing value-added NH₃, and advancing sustainable agriculture practices.