In-situ synthesized PtZnCu nanoalloy on carbon cloth for ultrasensitive electrochemical ammonia-nitrogen detection

Nanoalloy materials showed excellent, sensitive properties in the research field of ammonia‑nitrogen electrochemical sensors, which have been widely used by researchers. The PtZnCu ternary nanoalloy electrode based on a carbon cloth substrate (PtZnCu-CC) was prepared using one-step electrodeposition. The characterization results showed that the alloying of Zn, Cu and Pt regulated the electronic structure of Pt and enhanced the electrocatalytic oxidation capacity of Pt for ammonia‑nitrogen. Meanwhile, it was proved by density functional theory (DFT) that PtZnCu nanoalloy fully inherited the advantages of PtCu and PtZn nanoalloy, which not only enhanced the adsorption capacity of ammonia but also balanced the free energy of each step. Finally, the sensitivity of the whole electrode to ammonia‑nitrogen was improved. The linear detection range of the sensor based on PtZnCu-CC electrode for ammonia‑nitrogen was 0.5–1000 μM, the sensitivity was 23.9 μA μM⁻¹ cm⁻², and the limit of detection (LOD) was 8.37 nM, which showed satisfactory repeatability, anti-interference and stability. This work provided a specific direction for designing high-performance electrochemical sensors.