Fabrication of core–shell Pt–Ni(OH)2 nanosheets on Ni foam and investigation on its detection performance of ammonia–nitrogen in lake and sea water

Ammonia-nitrogen is one potential toxic pollutant. Detecting ammonia-nitrogen is meaningful for environment, food and human health. Therefore, designing and developing high-performance sensors is important to detect ammonia-nitrogen. An electrochemical sensor for ammonia-nitrogen detection was obtained based on core-shell Pt–Ni(OH)2 nanosheets on Ni foam (Pt–Ni(OH)2-NF) as a sensing electrode. The Pt–Ni(OH)2-NF sensor exhibited high sensitivity and low limit of detection due to the high catalytic activity of Pt towards ammonia oxidation reaction, large specific surface area and high-quality ohmic contact among Pt (outer layer), β-Ni(OH)2 (middle layer) and Ni (bottom layer). Furthermore, the representative Pt–Ni(OH)2-NF sensor was applied successfully to detect ammonia-nitrogen in lake and sea water, achieving accepted recoveries. Therefore, this Pt–Ni(OH)2-NF sensor presented great potential for practical application.