Enhanced Roughness of Graphene Foam for Optimizing Surface Active Copper With Efficient Electrochemical Detection of Nitrate

In light of the growing concern over nitrate pollution, developing convenient and efficient electrochemical sensors for nitrate ions is crucial for enhancing the monitoring of drinking water and food safety. To improve the sensitivity and stability of copper-based electrodes for nitrate detection, the ultra-high conductivity graphene foam developed by the group is utilized as a supporting electrode for copper. By increasing the surface roughness of the graphene foam, its binding interaction with copper is enhanced, which significantly improved electron transfer efficiency and stability in the composite electrode during electrochemical nitrate detection. Concretely, the roughened graphene foam surface promotes the formation of a dense copper layer and a higher content of Cu(OH)₂ as well as oxygen defects, which enhances nitrate adsorption and further improves detection sensitivity. The resulting composite electrode achieves an impressive detection limit of 1.78 µm. This study demonstrates that optimizing the surface roughness of graphene foam can significantly enhance the electrochemical performance of composite electrodes, offering valuable insights for the design and development of next-generation, highly active composite electrodes.