Abstract: Nitrate (NO₃^-) pollution in water has become a significant environmental issue, while ammonia, as an important chemical raw material and a potential energy carrier, holds high value. The electrochemical nitrate reduction reaction (eNO₃RR) offers a green and controllable new approach for the resource utilization of nitrate. This paper presents a teaching experiment on electrochemical nitrate reduction based on a Cu_xO catalyst. By directionally converting nitrate from wastewater into ammonia, the experiment aims to achieve both wastewater treatment and the production of a high-value product, effectively “killing two birds with one stone”. During the experiment, students can intuitively observe the color changes from copper foam to copper hydroxide and then to copper oxide during the catalyst preparation stage, the gas evolution phenomenon at the electrode during electrolysis, and the color reaction during ammonia detection. This deepens their understanding of the fundamental principles of electrocatalysis and the mechanism of electrochemical cathode reactions. With its simple operation and intuitive phenomena, this experiment holds significant value for teaching demonstration. This experiment can serve as a comprehensive experiment in materials chemistry titled “electrochemical method for directional conversion of nitrate in wastewater into high-value-added ammonia” for fourth-year undergraduate students, effectively enhancing their comprehensive knowledge application ability and scientific literacy.

Key words: Material chemistry, Comprehensive teaching experiment, Electrochemistry, Nitrate reduction reaction, Ammonia synthesis